/*
  * copyright (c) 2001 Fabrice Bellard
  *

  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either

  * version 2.1 of the License, or (at your option) any later version.

  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */
 

 #ifndef AVCODEC_AVCODEC_H
 #define AVCODEC_AVCODEC_H

 /**

  * @file

  * external API header

  */
 

 #include <errno.h>

 #include "libavutil/samplefmt.h"

 #include "libavutil/avutil.h"

 #include "libavutil/cpu.h"

 #include "libavutil/dict.h"

 #include "libavutil/log.h"

 #include "libavutil/pixfmt.h"

 #include "libavutil/rational.h"

 #include "libavcodec/version.h"

 /**
  * @defgroup libavc Encoding/Decoding Library
  * @{
  *
  * @defgroup lavc_decoding Decoding
  * @{
  * @}
  *
  * @defgroup lavc_encoding Encoding
  * @{
  * @}
  *
  * @defgroup lavc_codec Codecs
  * @{
  * @defgroup lavc_codec_native Native Codecs
  * @{
  * @}
  * @defgroup lavc_codec_wrappers External library wrappers
  * @{
  * @}
  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
  * @{
  * @}
  * @}
  * @defgroup lavc_internal Internal
  * @{
  * @}
  * @}
  *
  */
 

 /**

  * Identify the syntax and semantics of the bitstream.

  * The principle is roughly:
  * Two decoders with the same ID can decode the same streams.
  * Two encoders with the same ID can encode compatible streams.
  * There may be slight deviations from the principle due to implementation
  * details.

  *

  * If you add a codec ID to this list, add it so that
  * 1. no value of a existing codec ID changes (that would break ABI),

  * 2. Give it a value which when taken as ASCII is recognized uniquely by a human as this specific codec.
  *    This ensures that 2 forks can independantly add CodecIDs without producing conflicts.

  */

 enum CodecID {

     CODEC_ID_NONE,

 
     /* video codecs */

     CODEC_ID_MPEG1VIDEO,

     CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding

     CODEC_ID_MPEG2VIDEO_XVMC,

     CODEC_ID_H261,

     CODEC_ID_H263,
     CODEC_ID_RV10,

     CODEC_ID_RV20,

     CODEC_ID_MJPEG,

     CODEC_ID_MJPEGB,

     CODEC_ID_LJPEG,

     CODEC_ID_SP5X,

     CODEC_ID_JPEGLS,

     CODEC_ID_MPEG4,

     CODEC_ID_RAWVIDEO,

     CODEC_ID_MSMPEG4V1,
     CODEC_ID_MSMPEG4V2,
     CODEC_ID_MSMPEG4V3,

     CODEC_ID_WMV1,

     CODEC_ID_WMV2,

     CODEC_ID_H263P,
     CODEC_ID_H263I,

     CODEC_ID_FLV1,

     CODEC_ID_SVQ1,

     CODEC_ID_SVQ3,

     CODEC_ID_DVVIDEO,

     CODEC_ID_HUFFYUV,

     CODEC_ID_CYUV,

     CODEC_ID_H264,

     CODEC_ID_INDEO3,

     CODEC_ID_VP3,

     CODEC_ID_THEORA,

     CODEC_ID_ASV1,

     CODEC_ID_ASV2,

     CODEC_ID_FFV1,

     CODEC_ID_4XM,

     CODEC_ID_VCR1,

     CODEC_ID_CLJR,

     CODEC_ID_MDEC,

     CODEC_ID_ROQ,
     CODEC_ID_INTERPLAY_VIDEO,

     CODEC_ID_XAN_WC3,
     CODEC_ID_XAN_WC4,

     CODEC_ID_RPZA,
     CODEC_ID_CINEPAK,
     CODEC_ID_WS_VQA,
     CODEC_ID_MSRLE,
     CODEC_ID_MSVIDEO1,

     CODEC_ID_IDCIN,

     CODEC_ID_8BPS,

     CODEC_ID_SMC,

     CODEC_ID_FLIC,

     CODEC_ID_TRUEMOTION1,

     CODEC_ID_VMDVIDEO,

     CODEC_ID_MSZH,
     CODEC_ID_ZLIB,

     CODEC_ID_QTRLE,

     CODEC_ID_SNOW,

     CODEC_ID_TSCC,

     CODEC_ID_ULTI,

     CODEC_ID_QDRAW,

     CODEC_ID_VIXL,

     CODEC_ID_QPEG,

     CODEC_ID_PNG,
     CODEC_ID_PPM,
     CODEC_ID_PBM,
     CODEC_ID_PGM,
     CODEC_ID_PGMYUV,
     CODEC_ID_PAM,

     CODEC_ID_FFVHUFF,

     CODEC_ID_RV30,
     CODEC_ID_RV40,

     CODEC_ID_VC1,

     CODEC_ID_WMV3,

     CODEC_ID_LOCO,

     CODEC_ID_WNV1,

     CODEC_ID_AASC,

     CODEC_ID_INDEO2,

     CODEC_ID_FRAPS,

     CODEC_ID_TRUEMOTION2,

     CODEC_ID_BMP,

     CODEC_ID_CSCD,

     CODEC_ID_MMVIDEO,

     CODEC_ID_ZMBV,

     CODEC_ID_AVS,

     CODEC_ID_SMACKVIDEO,

     CODEC_ID_NUV,

     CODEC_ID_KMVC,

     CODEC_ID_FLASHSV,

     CODEC_ID_CAVS,

     CODEC_ID_JPEG2000,

     CODEC_ID_VMNC,

     CODEC_ID_VP5,
     CODEC_ID_VP6,
     CODEC_ID_VP6F,

     CODEC_ID_TARGA,

     CODEC_ID_DSICINVIDEO,

     CODEC_ID_TIERTEXSEQVIDEO,

     CODEC_ID_TIFF,

     CODEC_ID_GIF,

 #if LIBAVCODEC_VERSION_MAJOR == 53

     CODEC_ID_FFH264,

 #endif

     CODEC_ID_DXA,

     CODEC_ID_DNXHD,

     CODEC_ID_THP,

     CODEC_ID_SGI,

     CODEC_ID_C93,

     CODEC_ID_BETHSOFTVID,

     CODEC_ID_PTX,

     CODEC_ID_TXD,

     CODEC_ID_VP6A,

     CODEC_ID_AMV,

     CODEC_ID_VB,

     CODEC_ID_PCX,

     CODEC_ID_SUNRAST,

     CODEC_ID_INDEO4,
     CODEC_ID_INDEO5,

     CODEC_ID_MIMIC,

     CODEC_ID_RL2,

 #if LIBAVCODEC_VERSION_MAJOR == 53

     CODEC_ID_8SVX_EXP,
     CODEC_ID_8SVX_FIB,

 #endif

     CODEC_ID_ESCAPE124,

     CODEC_ID_DIRAC,

     CODEC_ID_BFI,

     CODEC_ID_CMV,

     CODEC_ID_MOTIONPIXELS,

     CODEC_ID_TGV,

     CODEC_ID_TGQ,

     CODEC_ID_TQI,

     CODEC_ID_AURA,
     CODEC_ID_AURA2,

     CODEC_ID_V210X,

     CODEC_ID_TMV,

     CODEC_ID_V210,

     CODEC_ID_DPX,

     CODEC_ID_MAD,

     CODEC_ID_FRWU,

     CODEC_ID_FLASHSV2,

     CODEC_ID_CDGRAPHICS,

     CODEC_ID_R210,

     CODEC_ID_ANM,

     CODEC_ID_BINKVIDEO,

     CODEC_ID_IFF_ILBM,
     CODEC_ID_IFF_BYTERUN1,

     CODEC_ID_KGV1,

     CODEC_ID_YOP,

     CODEC_ID_VP8,

     CODEC_ID_PICTOR,

     CODEC_ID_ANSI,

     CODEC_ID_A64_MULTI,
     CODEC_ID_A64_MULTI5,

     CODEC_ID_R10K,

     CODEC_ID_MXPEG,

     CODEC_ID_LAGARITH,

     CODEC_ID_PRORES,

     CODEC_ID_JV,

     CODEC_ID_DFA,

     CODEC_ID_WMV3IMAGE,
     CODEC_ID_VC1IMAGE,

 #if LIBAVCODEC_VERSION_MAJOR == 53

     CODEC_ID_G723_1_DEPRECATED,
     CODEC_ID_G729_DEPRECATED,

 #endif

     CODEC_ID_UTVIDEO_DEPRECATED,

     CODEC_ID_BMV_VIDEO,

     CODEC_ID_VBLE,

     CODEC_ID_DXTORY,

     CODEC_ID_V410,

     CODEC_ID_Y41P       = MKBETAG('Y','4','1','P'),

     CODEC_ID_UTVIDEO = 0x800,

     CODEC_ID_ESCAPE130  = MKBETAG('E','1','3','0'),

     CODEC_ID_G2M        = MKBETAG( 0 ,'G','2','M'),
 

     /* various PCM "codecs" */

     CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs

     CODEC_ID_PCM_S16LE = 0x10000,

     CODEC_ID_PCM_S16BE,
     CODEC_ID_PCM_U16LE,
     CODEC_ID_PCM_U16BE,
     CODEC_ID_PCM_S8,
     CODEC_ID_PCM_U8,
     CODEC_ID_PCM_MULAW,
     CODEC_ID_PCM_ALAW,

     CODEC_ID_PCM_S32LE,
     CODEC_ID_PCM_S32BE,
     CODEC_ID_PCM_U32LE,
     CODEC_ID_PCM_U32BE,
     CODEC_ID_PCM_S24LE,
     CODEC_ID_PCM_S24BE,
     CODEC_ID_PCM_U24LE,
     CODEC_ID_PCM_U24BE,
     CODEC_ID_PCM_S24DAUD,

     CODEC_ID_PCM_ZORK,

     CODEC_ID_PCM_S16LE_PLANAR,

     CODEC_ID_PCM_DVD,

     CODEC_ID_PCM_F32BE,

     CODEC_ID_PCM_F32LE,
     CODEC_ID_PCM_F64BE,
     CODEC_ID_PCM_F64LE,

     CODEC_ID_PCM_BLURAY,

     CODEC_ID_PCM_LXF,

     CODEC_ID_S302M,

     CODEC_ID_PCM_S8_PLANAR,

     /* various ADPCM codecs */

     CODEC_ID_ADPCM_IMA_QT = 0x11000,

     CODEC_ID_ADPCM_IMA_WAV,

     CODEC_ID_ADPCM_IMA_DK3,
     CODEC_ID_ADPCM_IMA_DK4,

     CODEC_ID_ADPCM_IMA_WS,

     CODEC_ID_ADPCM_IMA_SMJPEG,

     CODEC_ID_ADPCM_MS,

     CODEC_ID_ADPCM_4XM,

     CODEC_ID_ADPCM_XA,
     CODEC_ID_ADPCM_ADX,

     CODEC_ID_ADPCM_EA,

     CODEC_ID_ADPCM_G726,

     CODEC_ID_ADPCM_CT,

     CODEC_ID_ADPCM_SWF,

     CODEC_ID_ADPCM_YAMAHA,

     CODEC_ID_ADPCM_SBPRO_4,
     CODEC_ID_ADPCM_SBPRO_3,
     CODEC_ID_ADPCM_SBPRO_2,

     CODEC_ID_ADPCM_THP,

     CODEC_ID_ADPCM_IMA_AMV,

     CODEC_ID_ADPCM_EA_R1,
     CODEC_ID_ADPCM_EA_R3,
     CODEC_ID_ADPCM_EA_R2,

     CODEC_ID_ADPCM_IMA_EA_SEAD,

     CODEC_ID_ADPCM_IMA_EA_EACS,

     CODEC_ID_ADPCM_EA_XAS,

     CODEC_ID_ADPCM_EA_MAXIS_XA,

     CODEC_ID_ADPCM_IMA_ISS,

     CODEC_ID_ADPCM_G722,

     /* AMR */

     CODEC_ID_AMR_NB = 0x12000,

     CODEC_ID_AMR_WB,
 

     /* RealAudio codecs*/

     CODEC_ID_RA_144 = 0x13000,

     CODEC_ID_RA_288,

 
     /* various DPCM codecs */

     CODEC_ID_ROQ_DPCM = 0x14000,

     CODEC_ID_INTERPLAY_DPCM,

     CODEC_ID_XAN_DPCM,

     CODEC_ID_SOL_DPCM,

     /* audio codecs */

     CODEC_ID_MP2 = 0x15000,

     CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3

     CODEC_ID_AAC,
     CODEC_ID_AC3,
     CODEC_ID_DTS,
     CODEC_ID_VORBIS,
     CODEC_ID_DVAUDIO,
     CODEC_ID_WMAV1,
     CODEC_ID_WMAV2,
     CODEC_ID_MACE3,
     CODEC_ID_MACE6,
     CODEC_ID_VMDAUDIO,

 #if LIBAVCODEC_VERSION_MAJOR == 53

     CODEC_ID_SONIC,
     CODEC_ID_SONIC_LS,

 #endif

     CODEC_ID_FLAC,

     CODEC_ID_MP3ADU,

     CODEC_ID_MP3ON4,

     CODEC_ID_SHORTEN,

     CODEC_ID_ALAC,

     CODEC_ID_WESTWOOD_SND1,

     CODEC_ID_GSM, ///< as in Berlin toast format

     CODEC_ID_QDM2,

     CODEC_ID_COOK,

     CODEC_ID_TRUESPEECH,

     CODEC_ID_TTA,

     CODEC_ID_SMACKAUDIO,

     CODEC_ID_QCELP,

     CODEC_ID_WAVPACK,

     CODEC_ID_DSICINAUDIO,

     CODEC_ID_IMC,

     CODEC_ID_MUSEPACK7,

     CODEC_ID_MLP,

     CODEC_ID_GSM_MS, /* as found in WAV */

     CODEC_ID_ATRAC3,

     CODEC_ID_VOXWARE,

     CODEC_ID_APE,

     CODEC_ID_NELLYMOSER,

     CODEC_ID_MUSEPACK8,

     CODEC_ID_SPEEX,

     CODEC_ID_WMAVOICE,
     CODEC_ID_WMAPRO,

     CODEC_ID_WMALOSSLESS,

     CODEC_ID_ATRAC3P,

     CODEC_ID_EAC3,

     CODEC_ID_SIPR,

     CODEC_ID_MP1,

     CODEC_ID_TWINVQ,

     CODEC_ID_TRUEHD,

     CODEC_ID_MP4ALS,

     CODEC_ID_ATRAC1,

     CODEC_ID_BINKAUDIO_RDFT,
     CODEC_ID_BINKAUDIO_DCT,

     CODEC_ID_AAC_LATM,

     CODEC_ID_QDMC,

     CODEC_ID_CELT,

 #if LIBAVCODEC_VERSION_MAJOR > 53

     CODEC_ID_G723_1_DEPRECATED,
     CODEC_ID_G729_DEPRECATED,

     CODEC_ID_8SVX_EXP,
     CODEC_ID_8SVX_FIB,

 #endif

     CODEC_ID_BMV_AUDIO,

     CODEC_ID_G729 = 0x15800,

     CODEC_ID_G723_1= 0x15801,

     CODEC_ID_8SVX_RAW   = MKBETAG('8','S','V','X'),

     /* subtitle codecs */

     CODEC_ID_FIRST_SUBTITLE = 0x17000,          ///< A dummy ID pointing at the start of subtitle codecs.

     CODEC_ID_DVD_SUBTITLE = 0x17000,

     CODEC_ID_DVB_SUBTITLE,

     CODEC_ID_TEXT,  ///< raw UTF-8 text

     CODEC_ID_XSUB,

     CODEC_ID_SSA,

     CODEC_ID_MOV_TEXT,

     CODEC_ID_HDMV_PGS_SUBTITLE,

     CODEC_ID_DVB_TELETEXT,

     CODEC_ID_SRT,

     CODEC_ID_MICRODVD   = MKBETAG('m','D','V','D'),

     /* other specific kind of codecs (generally used for attachments) */

     CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.

     CODEC_ID_TTF = 0x18000,

     CODEC_ID_BINTEXT    = MKBETAG('B','T','X','T'),
     CODEC_ID_XBIN       = MKBETAG('X','B','I','N'),
     CODEC_ID_IDF        = MKBETAG( 0 ,'I','D','F'),

     CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like CODEC_ID_NONE) but lavf should attempt to identify it

     CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS

                                 * stream (only used by libavformat) */

     CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
                                 * stream (only used by libavformat) */

     CODEC_ID_FFMETADATA = 0x21000,   ///< Dummy codec for streams containing only metadata information.

 };

 #if FF_API_OLD_SAMPLE_FMT
 #define SampleFormat AVSampleFormat
 
 #define SAMPLE_FMT_NONE AV_SAMPLE_FMT_NONE
 #define SAMPLE_FMT_U8   AV_SAMPLE_FMT_U8
 #define SAMPLE_FMT_S16  AV_SAMPLE_FMT_S16
 #define SAMPLE_FMT_S32  AV_SAMPLE_FMT_S32
 #define SAMPLE_FMT_FLT  AV_SAMPLE_FMT_FLT
 #define SAMPLE_FMT_DBL  AV_SAMPLE_FMT_DBL
 #define SAMPLE_FMT_NB   AV_SAMPLE_FMT_NB
 #endif

 #if FF_API_OLD_AUDIOCONVERT

 #include "libavutil/audioconvert.h"

 /* Audio channel masks */

 #define CH_FRONT_LEFT            AV_CH_FRONT_LEFT
 #define CH_FRONT_RIGHT           AV_CH_FRONT_RIGHT
 #define CH_FRONT_CENTER          AV_CH_FRONT_CENTER
 #define CH_LOW_FREQUENCY         AV_CH_LOW_FREQUENCY
 #define CH_BACK_LEFT             AV_CH_BACK_LEFT
 #define CH_BACK_RIGHT            AV_CH_BACK_RIGHT
 #define CH_FRONT_LEFT_OF_CENTER  AV_CH_FRONT_LEFT_OF_CENTER
 #define CH_FRONT_RIGHT_OF_CENTER AV_CH_FRONT_RIGHT_OF_CENTER
 #define CH_BACK_CENTER           AV_CH_BACK_CENTER
 #define CH_SIDE_LEFT             AV_CH_SIDE_LEFT
 #define CH_SIDE_RIGHT            AV_CH_SIDE_RIGHT
 #define CH_TOP_CENTER            AV_CH_TOP_CENTER
 #define CH_TOP_FRONT_LEFT        AV_CH_TOP_FRONT_LEFT
 #define CH_TOP_FRONT_CENTER      AV_CH_TOP_FRONT_CENTER
 #define CH_TOP_FRONT_RIGHT       AV_CH_TOP_FRONT_RIGHT
 #define CH_TOP_BACK_LEFT         AV_CH_TOP_BACK_LEFT
 #define CH_TOP_BACK_CENTER       AV_CH_TOP_BACK_CENTER
 #define CH_TOP_BACK_RIGHT        AV_CH_TOP_BACK_RIGHT
 #define CH_STEREO_LEFT           AV_CH_STEREO_LEFT
 #define CH_STEREO_RIGHT          AV_CH_STEREO_RIGHT

 /** Channel mask value used for AVCodecContext.request_channel_layout
     to indicate that the user requests the channel order of the decoder output
     to be the native codec channel order. */

 #define CH_LAYOUT_NATIVE         AV_CH_LAYOUT_NATIVE

 /* Audio channel convenience macros */

 #define CH_LAYOUT_MONO           AV_CH_LAYOUT_MONO
 #define CH_LAYOUT_STEREO         AV_CH_LAYOUT_STEREO
 #define CH_LAYOUT_2_1            AV_CH_LAYOUT_2_1
 #define CH_LAYOUT_SURROUND       AV_CH_LAYOUT_SURROUND
 #define CH_LAYOUT_4POINT0        AV_CH_LAYOUT_4POINT0
 #define CH_LAYOUT_2_2            AV_CH_LAYOUT_2_2
 #define CH_LAYOUT_QUAD           AV_CH_LAYOUT_QUAD
 #define CH_LAYOUT_5POINT0        AV_CH_LAYOUT_5POINT0
 #define CH_LAYOUT_5POINT1        AV_CH_LAYOUT_5POINT1
 #define CH_LAYOUT_5POINT0_BACK   AV_CH_LAYOUT_5POINT0_BACK
 #define CH_LAYOUT_5POINT1_BACK   AV_CH_LAYOUT_5POINT1_BACK
 #define CH_LAYOUT_7POINT0        AV_CH_LAYOUT_7POINT0
 #define CH_LAYOUT_7POINT1        AV_CH_LAYOUT_7POINT1
 #define CH_LAYOUT_7POINT1_WIDE   AV_CH_LAYOUT_7POINT1_WIDE
 #define CH_LAYOUT_STEREO_DOWNMIX AV_CH_LAYOUT_STEREO_DOWNMIX
 #endif

 #if FF_API_OLD_DECODE_AUDIO

 /* in bytes */

 #define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio

 #endif

 /**

  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.

  * This is mainly needed because some optimized bitstream readers read
  * 32 or 64 bit at once and could read over the end.<br>

  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
  * MPEG bitstreams could cause overread and segfault.

  */

 #define FF_INPUT_BUFFER_PADDING_SIZE 16

 /**

  * minimum encoding buffer size
  * Used to avoid some checks during header writing.

  */
 #define FF_MIN_BUFFER_SIZE 16384
 

 /**

  * motion estimation type.

  */

 enum Motion_Est_ID {

     ME_ZERO = 1,    ///< no search, that is use 0,0 vector whenever one is needed

     ME_FULL,
     ME_LOG,
     ME_PHODS,

     ME_EPZS,        ///< enhanced predictive zonal search
     ME_X1,          ///< reserved for experiments
     ME_HEX,         ///< hexagon based search
     ME_UMH,         ///< uneven multi-hexagon search
     ME_ITER,        ///< iterative search

     ME_TESA,        ///< transformed exhaustive search algorithm

 };
 

 enum AVDiscard{

     /* We leave some space between them for extensions (drop some
      * keyframes for intra-only or drop just some bidir frames). */

     AVDISCARD_NONE   =-16, ///< discard nothing
     AVDISCARD_DEFAULT=  0, ///< discard useless packets like 0 size packets in avi
     AVDISCARD_NONREF =  8, ///< discard all non reference
     AVDISCARD_BIDIR  = 16, ///< discard all bidirectional frames
     AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
     AVDISCARD_ALL    = 48, ///< discard all
 };
 

 enum AVColorPrimaries{
     AVCOL_PRI_BT709      =1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
     AVCOL_PRI_UNSPECIFIED=2,
     AVCOL_PRI_BT470M     =4,
     AVCOL_PRI_BT470BG    =5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
     AVCOL_PRI_SMPTE170M  =6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
     AVCOL_PRI_SMPTE240M  =7, ///< functionally identical to above
     AVCOL_PRI_FILM       =8,
     AVCOL_PRI_NB           , ///< Not part of ABI
 };
 
 enum AVColorTransferCharacteristic{
     AVCOL_TRC_BT709      =1, ///< also ITU-R BT1361
     AVCOL_TRC_UNSPECIFIED=2,
     AVCOL_TRC_GAMMA22    =4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
     AVCOL_TRC_GAMMA28    =5, ///< also ITU-R BT470BG

     AVCOL_TRC_SMPTE240M  =7,

     AVCOL_TRC_NB           , ///< Not part of ABI
 };
 
 enum AVColorSpace{
     AVCOL_SPC_RGB        =0,
     AVCOL_SPC_BT709      =1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
     AVCOL_SPC_UNSPECIFIED=2,
     AVCOL_SPC_FCC        =4,
     AVCOL_SPC_BT470BG    =5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
     AVCOL_SPC_SMPTE170M  =6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
     AVCOL_SPC_SMPTE240M  =7,

     AVCOL_SPC_YCGCO      =8,

     AVCOL_SPC_NB           , ///< Not part of ABI
 };
 
 enum AVColorRange{
     AVCOL_RANGE_UNSPECIFIED=0,
     AVCOL_RANGE_MPEG       =1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
     AVCOL_RANGE_JPEG       =2, ///< the normal     2^n-1   "JPEG" YUV ranges
     AVCOL_RANGE_NB           , ///< Not part of ABI
 };
 

 /**
  *  X   X      3 4 X      X are luma samples,
  *             1 2        1-6 are possible chroma positions
  *  X   X      5 6 X      0 is undefined/unknown position
  */
 enum AVChromaLocation{
     AVCHROMA_LOC_UNSPECIFIED=0,
     AVCHROMA_LOC_LEFT       =1, ///< mpeg2/4, h264 default
     AVCHROMA_LOC_CENTER     =2, ///< mpeg1, jpeg, h263
     AVCHROMA_LOC_TOPLEFT    =3, ///< DV
     AVCHROMA_LOC_TOP        =4,
     AVCHROMA_LOC_BOTTOMLEFT =5,
     AVCHROMA_LOC_BOTTOM     =6,
     AVCHROMA_LOC_NB           , ///< Not part of ABI
 };
 

 #if FF_API_FLAC_GLOBAL_OPTS

 /**
  * LPC analysis type
  */

 enum AVLPCType {

     AV_LPC_TYPE_DEFAULT     = -1, ///< use the codec default LPC type
     AV_LPC_TYPE_NONE        =  0, ///< do not use LPC prediction or use all zero coefficients
     AV_LPC_TYPE_FIXED       =  1, ///< fixed LPC coefficients
     AV_LPC_TYPE_LEVINSON    =  2, ///< Levinson-Durbin recursion
     AV_LPC_TYPE_CHOLESKY    =  3, ///< Cholesky factorization
     AV_LPC_TYPE_NB              , ///< Not part of ABI
 };

 #endif

 enum AVAudioServiceType {
     AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
     AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
     AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
     AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
     AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
     AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
     AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
     AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
     AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
     AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
 };
 

 typedef struct RcOverride{
     int start_frame;
     int end_frame;

     int qscale; // If this is 0 then quality_factor will be used instead.

     float quality_factor;
 } RcOverride;
 

 #define FF_MAX_B_FRAMES 16

 /* encoding support

    These flags can be passed in AVCodecContext.flags before initialization.
    Note: Not everything is supported yet.

 */

 #define CODEC_FLAG_QSCALE 0x0002  ///< Use fixed qscale.
 #define CODEC_FLAG_4MV    0x0004  ///< 4 MV per MB allowed / advanced prediction for H.263.
 #define CODEC_FLAG_QPEL   0x0010  ///< Use qpel MC.
 #define CODEC_FLAG_GMC    0x0020  ///< Use GMC.
 #define CODEC_FLAG_MV0    0x0040  ///< Always try a MB with MV=<0,0>.

 /**
  * The parent program guarantees that the input for B-frames containing

  * streams is not written to for at least s->max_b_frames+1 frames, if

  * this is not set the input will be copied.
  */

 #define CODEC_FLAG_INPUT_PRESERVED 0x0100

 #define CODEC_FLAG_PASS1           0x0200   ///< Use internal 2pass ratecontrol in first pass mode.
 #define CODEC_FLAG_PASS2           0x0400   ///< Use internal 2pass ratecontrol in second pass mode.
 #define CODEC_FLAG_GRAY            0x2000   ///< Only decode/encode grayscale.
 #define CODEC_FLAG_EMU_EDGE        0x4000   ///< Don't draw edges.
 #define CODEC_FLAG_PSNR            0x8000   ///< error[?] variables will be set during encoding.
 #define CODEC_FLAG_TRUNCATED       0x00010000 /** Input bitstream might be truncated at a random
                                                   location instead of only at frame boundaries. */

 #define CODEC_FLAG_NORMALIZE_AQP  0x00020000 ///< Normalize adaptive quantization.
 #define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
 #define CODEC_FLAG_LOW_DELAY      0x00080000 ///< Force low delay.
 #define CODEC_FLAG_GLOBAL_HEADER  0x00400000 ///< Place global headers in extradata instead of every keyframe.
 #define CODEC_FLAG_BITEXACT       0x00800000 ///< Use only bitexact stuff (except (I)DCT).

 /* Fx : Flag for h263+ extra options */

 #define CODEC_FLAG_AC_PRED        0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
 #define CODEC_FLAG_CBP_RD         0x04000000 ///< Use rate distortion optimization for cbp.
 #define CODEC_FLAG_QP_RD          0x08000000 ///< Use rate distortion optimization for qp selectioon.

 #define CODEC_FLAG_LOOP_FILTER    0x00000800 ///< loop filter

 #define CODEC_FLAG_INTERLACED_ME  0x20000000 ///< interlaced motion estimation

 #define CODEC_FLAG_CLOSED_GOP     0x80000000

 #define CODEC_FLAG2_FAST          0x00000001 ///< Allow non spec compliant speedup tricks.
 #define CODEC_FLAG2_STRICT_GOP    0x00000002 ///< Strictly enforce GOP size.
 #define CODEC_FLAG2_NO_OUTPUT     0x00000004 ///< Skip bitstream encoding.
 #define CODEC_FLAG2_LOCAL_HEADER  0x00000008 ///< Place global headers at every keyframe instead of in extradata.

 #define CODEC_FLAG2_SKIP_RD       0x00004000 ///< RD optimal MB level residual skipping
 #define CODEC_FLAG2_CHUNKS        0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.

 #define CODEC_FLAG2_SHOW_ALL      0x00400000 ///< Show all frames before the first keyframe

 /**
  * @defgroup deprecated_flags Deprecated codec flags
  * Use corresponding private codec options instead.
  * @{
  */
 #if FF_API_MPEGVIDEO_GLOBAL_OPTS
 #define CODEC_FLAG_OBMC           0x00000001 ///< OBMC
 #define CODEC_FLAG_H263P_AIV      0x00000008 ///< H.263 alternative inter VLC
 #define CODEC_FLAG_PART   0x0080  ///< Use data partitioning.
 #define CODEC_FLAG_ALT_SCAN       0x00100000 ///< Use alternate scan.
 #define CODEC_FLAG_H263P_UMV      0x02000000 ///< unlimited motion vector
 #define CODEC_FLAG_H263P_SLICE_STRUCT 0x10000000
 #define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< Will reserve space for SVCD scan offset user data.
 #define CODEC_FLAG2_INTRA_VLC     0x00000800 ///< Use MPEG-2 intra VLC table.
 #define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format.
 #define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< Use MPEG-2 nonlinear quantizer.
 #endif
 #if FF_API_MJPEG_GLOBAL_OPTS
 #define CODEC_FLAG_EXTERN_HUFF     0x1000   ///< Use external Huffman table (for MJPEG).
 #endif

 #if FF_API_X264_GLOBAL_OPTS

 #define CODEC_FLAG2_BPYRAMID      0x00000010 ///< H.264 allow B-frames to be used as references.
 #define CODEC_FLAG2_WPRED         0x00000020 ///< H.264 weighted biprediction for B-frames

 #define CODEC_FLAG2_MIXED_REFS    0x00000040 ///< H.264 one reference per partition, as opposed to one reference per macroblock

 #define CODEC_FLAG2_8X8DCT        0x00000080 ///< H.264 high profile 8x8 transform
 #define CODEC_FLAG2_FASTPSKIP     0x00000100 ///< H.264 fast pskip
 #define CODEC_FLAG2_AUD           0x00000200 ///< H.264 access unit delimiters

 #define CODEC_FLAG2_BRDO          0x00000400 ///< B-frame rate-distortion optimization

 #define CODEC_FLAG2_MBTREE        0x00040000 ///< Use macroblock tree ratecontrol (x264 only)

 #define CODEC_FLAG2_PSY           0x00080000 ///< Use psycho visual optimizations.
 #define CODEC_FLAG2_SSIM          0x00100000 ///< Compute SSIM during encoding, error[] values are undefined.

 #define CODEC_FLAG2_INTRA_REFRESH 0x00200000 ///< Use periodic insertion of intra blocks instead of keyframes.

 #endif

 #if FF_API_SNOW_GLOBAL_OPTS

 #define CODEC_FLAG2_MEMC_ONLY     0x00001000 ///< Only do ME/MC (I frames -> ref, P frame -> ME+MC).

 #endif

 #if FF_API_LAME_GLOBAL_OPTS

 #define CODEC_FLAG2_BIT_RESERVOIR 0x00020000 ///< Use a bit reservoir when encoding if possible

 #endif

 /**
  * @}
  */

 /* Unsupported options :

  *              Syntax Arithmetic coding (SAC)
  *              Reference Picture Selection

  *              Independent Segment Decoding */

 /* /Fx */

 /* codec capabilities */
 

 #define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.

 /**

  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
  * If not set, it might not use get_buffer() at all or use operations that
  * assume the buffer was allocated by avcodec_default_get_buffer.

  */
 #define CODEC_CAP_DR1             0x0002

 #if FF_API_PARSE_FRAME

 /* If 'parse_only' field is true, then avcodec_parse_frame() can be used. */

 #define CODEC_CAP_PARSE_ONLY      0x0004

 #endif

 #define CODEC_CAP_TRUNCATED       0x0008

 /* Codec can export data for HW decoding (XvMC). */

 #define CODEC_CAP_HWACCEL         0x0010

 /**

  * Codec has a nonzero delay and needs to be fed with avpkt->data=NULL,
  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
  * returns frames. If this is not set, the codec is guaranteed to never be fed
  * with NULL data.

  */

 #define CODEC_CAP_DELAY           0x0020

 /**
  * Codec can be fed a final frame with a smaller size.
  * This can be used to prevent truncation of the last audio samples.
  */
 #define CODEC_CAP_SMALL_LAST_FRAME 0x0040

 /**
  * Codec can export data for HW decoding (VDPAU).
  */
 #define CODEC_CAP_HWACCEL_VDPAU    0x0080

 /**
  * Codec can output multiple frames per AVPacket

  * Normally demuxers return one frame at a time, demuxers which do not do
  * are connected to a parser to split what they return into proper frames.
  * This flag is reserved to the very rare category of codecs which have a
  * bitstream that cannot be split into frames without timeconsuming
  * operations like full decoding. Demuxers carring such bitstreams thus
  * may return multiple frames in a packet. This has many disadvantages like
  * prohibiting stream copy in many cases thus it should only be considered
  * as a last resort.

  */
 #define CODEC_CAP_SUBFRAMES        0x0100

 /**
  * Codec is experimental and is thus avoided in favor of non experimental
  * encoders
  */
 #define CODEC_CAP_EXPERIMENTAL     0x0200

 /**
  * Codec should fill in channel configuration and samplerate instead of container
  */
 #define CODEC_CAP_CHANNEL_CONF     0x0400

 /**
  * Codec is able to deal with negative linesizes
  */
 #define CODEC_CAP_NEG_LINESIZES    0x0800

 /**
  * Codec supports frame-level multithreading.
  */
 #define CODEC_CAP_FRAME_THREADS    0x1000

 /**
  * Codec supports slice-based (or partition-based) multithreading.
  */
 #define CODEC_CAP_SLICE_THREADS    0x2000

 /**

  * Codec supports changed parameters at any point.
  */
 #define CODEC_CAP_PARAM_CHANGE     0x4000
 /**

  * Codec is lossless.
  */
 #define CODEC_CAP_LOSSLESS         0x80000000

 //The following defines may change, don't expect compatibility if you use them.

 #define MB_TYPE_INTRA4x4   0x0001

 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
 #define MB_TYPE_INTRA_PCM  0x0004 //FIXME H.264-specific

 #define MB_TYPE_16x16      0x0008
 #define MB_TYPE_16x8       0x0010
 #define MB_TYPE_8x16       0x0020
 #define MB_TYPE_8x8        0x0040
 #define MB_TYPE_INTERLACED 0x0080

 #define MB_TYPE_DIRECT2    0x0100 //FIXME

 #define MB_TYPE_ACPRED     0x0200
 #define MB_TYPE_GMC        0x0400
 #define MB_TYPE_SKIP       0x0800
 #define MB_TYPE_P0L0       0x1000
 #define MB_TYPE_P1L0       0x2000
 #define MB_TYPE_P0L1       0x4000
 #define MB_TYPE_P1L1       0x8000
 #define MB_TYPE_L0         (MB_TYPE_P0L0 | MB_TYPE_P1L0)
 #define MB_TYPE_L1         (MB_TYPE_P0L1 | MB_TYPE_P1L1)
 #define MB_TYPE_L0L1       (MB_TYPE_L0   | MB_TYPE_L1)
 #define MB_TYPE_QUANT      0x00010000
 #define MB_TYPE_CBP        0x00020000
 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
 

 /**
  * Pan Scan area.

  * This specifies the area which should be displayed.
  * Note there may be multiple such areas for one frame.

  */
 typedef struct AVPanScan{
     /**

      * id
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
     int id;
 
     /**
      * width and height in 1/16 pel

      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
     int width;
     int height;
 
     /**

      * position of the top left corner in 1/16 pel for up to 3 fields/frames
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
     int16_t position[3][2];
 }AVPanScan;
 

 #define FF_QSCALE_TYPE_MPEG1 0
 #define FF_QSCALE_TYPE_MPEG2 1
 #define FF_QSCALE_TYPE_H264  2

 #define FF_QSCALE_TYPE_VP56  3

 
 #define FF_BUFFER_TYPE_INTERNAL 1

 #define FF_BUFFER_TYPE_USER     2 ///< direct rendering buffers (image is (de)allocated by user)
 #define FF_BUFFER_TYPE_SHARED   4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
 #define FF_BUFFER_TYPE_COPY     8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.

 #if FF_API_OLD_FF_PICT_TYPES
 /* DEPRECATED, directly use the AV_PICTURE_TYPE_* enum values */
 #define FF_I_TYPE  AV_PICTURE_TYPE_I  ///< Intra
 #define FF_P_TYPE  AV_PICTURE_TYPE_P  ///< Predicted
 #define FF_B_TYPE  AV_PICTURE_TYPE_B  ///< Bi-dir predicted
 #define FF_S_TYPE  AV_PICTURE_TYPE_S  ///< S(GMC)-VOP MPEG4
 #define FF_SI_TYPE AV_PICTURE_TYPE_SI ///< Switching Intra
 #define FF_SP_TYPE AV_PICTURE_TYPE_SP ///< Switching Predicted
 #define FF_BI_TYPE AV_PICTURE_TYPE_BI
 #endif

 #define FF_BUFFER_HINTS_VALID    0x01 // Buffer hints value is meaningful (if 0 ignore).
 #define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
 #define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
 #define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).

 enum AVPacketSideDataType {
     AV_PKT_DATA_PALETTE,

     AV_PKT_DATA_NEW_EXTRADATA,

     AV_PKT_DATA_PARAM_CHANGE,

 };
 

 typedef struct AVPacket {
     /**

      * Presentation timestamp in AVStream->time_base units; the time at which
      * the decompressed packet will be presented to the user.

      * Can be AV_NOPTS_VALUE if it is not stored in the file.
      * pts MUST be larger or equal to dts as presentation cannot happen before
      * decompression, unless one wants to view hex dumps. Some formats misuse
      * the terms dts and pts/cts to mean something different. Such timestamps
      * must be converted to true pts/dts before they are stored in AVPacket.
      */
     int64_t pts;
     /**

      * Decompression timestamp in AVStream->time_base units; the time at which
      * the packet is decompressed.

      * Can be AV_NOPTS_VALUE if it is not stored in the file.
      */
     int64_t dts;
     uint8_t *data;
     int   size;
     int   stream_index;

     /**
      * A combination of AV_PKT_FLAG values
      */

     int   flags;
     /**

      * Additional packet data that can be provided by the container.
      * Packet can contain several types of side information.
      */
     struct {
         uint8_t *data;
         int      size;
         enum AVPacketSideDataType type;
     } *side_data;
     int side_data_elems;
 
     /**

      * Duration of this packet in AVStream->time_base units, 0 if unknown.

      * Equals next_pts - this_pts in presentation order.
      */
     int   duration;
     void  (*destruct)(struct AVPacket *);
     void  *priv;
     int64_t pos;                            ///< byte position in stream, -1 if unknown
 
     /**

      * Time difference in AVStream->time_base units from the pts of this

      * packet to the point at which the output from the decoder has converged
      * independent from the availability of previous frames. That is, the
      * frames are virtually identical no matter if decoding started from
      * the very first frame or from this keyframe.
      * Is AV_NOPTS_VALUE if unknown.
      * This field is not the display duration of the current packet.

      * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
      * set.

      *
      * The purpose of this field is to allow seeking in streams that have no
      * keyframes in the conventional sense. It corresponds to the
      * recovery point SEI in H.264 and match_time_delta in NUT. It is also
      * essential for some types of subtitle streams to ensure that all
      * subtitles are correctly displayed after seeking.
      */
     int64_t convergence_duration;
 } AVPacket;

 #define AV_PKT_FLAG_KEY     0x0001 ///< The packet contains a keyframe
 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted

 /**

  * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
  * u32le param_flags
  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
  *     s32le channel_count
  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
  *     u64le channel_layout
  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
  *     s32le sample_rate
  * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
  *     s32le width
  *     s32le height
  */
 
 enum AVSideDataParamChangeFlags {
     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT  = 0x0001,
     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
     AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE    = 0x0004,
     AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS     = 0x0008,
 };
 
 /**

  * Audio Video Frame.

  * New fields can be added to the end of AVFRAME with minor version

  * bumps. Similarly fields that are marked as to be only accessed by
  * av_opt_ptr() can be reordered. This allows 2 forks to add fields
  * without breaking compatibility with each other.
  * Removal, reordering and changes in the remaining cases require

  * a major version bump.

  * sizeof(AVFrame) must not be used outside libavcodec.

  */

 typedef struct AVFrame {

 #if FF_API_DATA_POINTERS
 #define AV_NUM_DATA_POINTERS 4
 #else
 #define AV_NUM_DATA_POINTERS 8
 #endif

     /**

      * pointer to the picture/channel planes.

      * This might be different from the first allocated byte

      * - encoding: Set by user
      * - decoding: set by AVCodecContext.get_buffer()

      */

     uint8_t *data[AV_NUM_DATA_POINTERS];

 
     /**
      * Size, in bytes, of the data for each picture/channel plane.
      *
      * For audio, only linesize[0] may be set. For planar audio, each channel
      * plane must be the same size.
      *
      * - encoding: Set by user (video only)
      * - decoding: set by AVCodecContext.get_buffer()

      */

     int linesize[AV_NUM_DATA_POINTERS];

     /**
      * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.
      * This isn't used by libavcodec unless the default get/release_buffer() is used.
      * - encoding:
      * - decoding:
      */

     uint8_t *base[AV_NUM_DATA_POINTERS];

     /**
      * 1 -> keyframe, 0-> not
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     int key_frame;
 
     /**
      * Picture type of the frame, see ?_TYPE below.
      * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
      * - decoding: Set by libavcodec.
      */
     enum AVPictureType pict_type;
 
     /**
      * presentation timestamp in time_base units (time when frame should be shown to user)
      * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.
      * - encoding: MUST be set by user.
      * - decoding: Set by libavcodec.
      */
     int64_t pts;
 
     /**
      * picture number in bitstream order
      * - encoding: set by
      * - decoding: Set by libavcodec.
      */
     int coded_picture_number;
     /**
      * picture number in display order
      * - encoding: set by
      * - decoding: Set by libavcodec.
      */
     int display_picture_number;
 
     /**
      * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
      * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
      * - decoding: Set by libavcodec.
      */
     int quality;
 
     /**
      * buffer age (1->was last buffer and dint change, 2->..., ...).
      * Set to INT_MAX if the buffer has not been used yet.
      * - encoding: unused

      * - decoding: MUST be set by get_buffer() for video.

      */
     int age;
 
     /**
      * is this picture used as reference
      * The values for this are the same as the MpegEncContext.picture_structure
      * variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
      * Set to 4 for delayed, non-reference frames.
      * - encoding: unused
      * - decoding: Set by libavcodec. (before get_buffer() call)).
      */
     int reference;
 
     /**
      * QP table
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     int8_t *qscale_table;
     /**
      * QP store stride
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     int qstride;
 
     /**
      * mbskip_table[mb]>=1 if MB didn't change
      * stride= mb_width = (width+15)>>4
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     uint8_t *mbskip_table;
 
     /**
      * motion vector table
      * @code
      * example:
      * int mv_sample_log2= 4 - motion_subsample_log2;
      * int mb_width= (width+15)>>4;
      * int mv_stride= (mb_width << mv_sample_log2) + 1;
      * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
      * @endcode
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     int16_t (*motion_val[2])[2];
 
     /**
      * macroblock type table
      * mb_type_base + mb_width + 2
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     uint32_t *mb_type;
 
     /**
      * log2 of the size of the block which a single vector in motion_val represents:
      * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     uint8_t motion_subsample_log2;
 
     /**
      * for some private data of the user
      * - encoding: unused
      * - decoding: Set by user.
      */
     void *opaque;
 
     /**
      * error
      * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.
      * - decoding: unused
      */

     uint64_t error[AV_NUM_DATA_POINTERS];

 
     /**
      * type of the buffer (to keep track of who has to deallocate data[*])
      * - encoding: Set by the one who allocates it.
      * - decoding: Set by the one who allocates it.
      * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.
      */
     int type;
 
     /**
      * When decoding, this signals how much the picture must be delayed.
      * extra_delay = repeat_pict / (2*fps)
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     int repeat_pict;
 
     /**
      *
      */
     int qscale_type;
 
     /**
      * The content of the picture is interlaced.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec. (default 0)
      */
     int interlaced_frame;
 
     /**
      * If the content is interlaced, is top field displayed first.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     int top_field_first;
 
     /**
      * Pan scan.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     AVPanScan *pan_scan;
 
     /**
      * Tell user application that palette has changed from previous frame.
      * - encoding: ??? (no palette-enabled encoder yet)
      * - decoding: Set by libavcodec. (default 0).
      */
     int palette_has_changed;
 
     /**
      * codec suggestion on buffer type if != 0
      * - encoding: unused
      * - decoding: Set by libavcodec. (before get_buffer() call)).
      */
     int buffer_hints;
 
     /**
      * DCT coefficients
      * - encoding: unused
      * - decoding: Set by libavcodec.
      */
     short *dct_coeff;
 
     /**
      * motion reference frame index
      * the order in which these are stored can depend on the codec.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     int8_t *ref_index[2];
 
     /**
      * reordered opaque 64bit (generally an integer or a double precision float
      * PTS but can be anything).
      * The user sets AVCodecContext.reordered_opaque to represent the input at
      * that time,
      * the decoder reorders values as needed and sets AVFrame.reordered_opaque
      * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
      * @deprecated in favor of pkt_pts
      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t reordered_opaque;
 
     /**

      * hardware accelerator private data (FFmpeg-allocated)

      * - encoding: unused
      * - decoding: Set by libavcodec
      */
     void *hwaccel_picture_private;
 
     /**
      * reordered pts from the last AVPacket that has been input into the decoder
      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t pkt_pts;
 
     /**
      * dts from the last AVPacket that has been input into the decoder
      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t pkt_dts;
 
     /**
      * the AVCodecContext which ff_thread_get_buffer() was last called on
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     struct AVCodecContext *owner;
 
     /**
      * used by multithreading to store frame-specific info
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     void *thread_opaque;

 
     /**

      * number of audio samples (per channel) described by this frame
      * - encoding: unused
      * - decoding: Set by libavcodec
      */
     int nb_samples;
 
     /**
      * pointers to the data planes/channels.
      *
      * For video, this should simply point to data[].
      *
      * For planar audio, each channel has a separate data pointer, and
      * linesize[0] contains the size of each channel buffer.
      * For packed audio, there is just one data pointer, and linesize[0]
      * contains the total size of the buffer for all channels.
      *
      * Note: Both data and extended_data will always be set by get_buffer(),
      * but for planar audio with more channels that can fit in data,
      * extended_data must be used by the decoder in order to access all
      * channels.
      *
      * encoding: unused
      * decoding: set by AVCodecContext.get_buffer()
      */
     uint8_t **extended_data;

 
     /**

      * frame timestamp estimated using various heuristics, in stream time base

      * Code outside libavcodec should access this field using:
      *  av_opt_ptr(avcodec_get_frame_class(), frame, "best_effort_timestamp");

      * - encoding: unused
      * - decoding: set by libavcodec, read by user.
      */
     int64_t best_effort_timestamp;
 
     /**
      * reordered pos from the last AVPacket that has been input into the decoder

      * Code outside libavcodec should access this field using:
      *  av_opt_ptr(avcodec_get_frame_class(), frame, "pkt_pos");

      * - encoding: unused
      * - decoding: Read by user.
      */
     int64_t pkt_pos;
 
     /**
      * reordered sample aspect ratio for the video frame, 0/1 if unknown\unspecified

      * Code outside libavcodec should access this field using:
      *  av_opt_ptr(avcodec_get_frame_class(), frame, "sample_aspect_ratio");

      * - encoding: unused
      * - decoding: Read by user.
      */
     AVRational sample_aspect_ratio;
 
     /**
      * width and height of the video frame

      * Code outside libavcodec should access this field using:
      *  av_opt_ptr(avcodec_get_frame_class(), frame, "width");

      * - encoding: unused
      * - decoding: Read by user.
      */
     int width, height;
 
     /**
      * format of the frame, -1 if unknown or unset
      * It should be cast to the corresponding enum (enum PixelFormat
      * for video, enum AVSampleFormat for audio)

      * Code outside libavcodec should access this field using:
      *  av_opt_ptr(avcodec_get_frame_class(), frame, "format");

      * - encoding: unused
      * - decoding: Read by user.
      */
     int format;
 

 } AVFrame;

 struct AVCodecInternal;
 

 /**

  * main external API structure.
  * New fields can be added to the end with minor version bumps.

  * Removal, reordering and changes to existing fields require a major

  * version bump.

  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user

  * applications.

  * sizeof(AVCodecContext) must not be used outside libav*.

  */

 typedef struct AVCodecContext {

     /**

      * information on struct for av_log

      * - set by avcodec_alloc_context3

      */

     const AVClass *av_class;

     /**

      * the average bitrate
      * - encoding: Set by user; unused for constant quantizer encoding.
      * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.

      */

     int bit_rate;

 
     /**

      * number of bits the bitstream is allowed to diverge from the reference.

      *           the reference can be CBR (for CBR pass1) or VBR (for pass2)

      * - encoding: Set by user; unused for constant quantizer encoding.

      * - decoding: unused

      */

     int bit_rate_tolerance;

 
     /**

      * CODEC_FLAG_*.

      * - encoding: Set by user.
      * - decoding: Set by user.

      */

     int flags;

 
     /**

      * Some codecs need additional format info. It is stored here.
      * If any muxer uses this then ALL demuxers/parsers AND encoders for the
      * specific codec MUST set it correctly otherwise stream copy breaks.
      * In general use of this field by muxers is not recommanded.
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec. (FIXME: Is this OK?)

      */
     int sub_id;
 
     /**

      * Motion estimation algorithm used for video coding.

      * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),

      * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]

      * - encoding: MUST be set by user.
      * - decoding: unused

      */
     int me_method;
 
     /**

      * some codecs need / can use extradata like Huffman tables.
      * mjpeg: Huffman tables

      * rv10: additional flags

      * mpeg4: global headers (they can be in the bitstream or here)

      * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
      * than extradata_size to avoid prolems if it is read with the bitstream reader.
      * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
      * - encoding: Set/allocated/freed by libavcodec.
      * - decoding: Set/allocated/freed by user.

      */

     uint8_t *extradata;

     int extradata_size;

     /**

      * This is the fundamental unit of time (in seconds) in terms
      * of which frame timestamps are represented. For fixed-fps content,

      * timebase should be 1/framerate and timestamp increments should be
      * identically 1.

      * - encoding: MUST be set by user.
      * - decoding: Set by libavcodec.

      */

     AVRational time_base;

     /* video only */

     /**

      * picture width / height.

      * - encoding: MUST be set by user.

      * - decoding: Set by libavcodec.
      * Note: For compatibility it is possible to set this instead of
      * coded_width/height before decoding.

      */

     int width, height;

 #define FF_ASPECT_EXTENDED 15

 
     /**

      * the number of pictures in a group of pictures, or 0 for intra_only
      * - encoding: Set by user.

      * - decoding: unused

      */
     int gop_size;
 
     /**

      * Pixel format, see PIX_FMT_xxx.

      * May be set by the demuxer if known from headers.
      * May be overriden by the decoder if it knows better.

      * - encoding: Set by user.

      * - decoding: Set by user if known, overridden by libavcodec if known

      */

     enum PixelFormat pix_fmt;

     /**

      * If non NULL, 'draw_horiz_band' is called by the libavcodec
      * decoder to draw a horizontal band. It improves cache usage. Not

      * all codecs can do that. You must check the codec capabilities

      * beforehand.

      * When multithreading is used, it may be called from multiple threads
      * at the same time; threads might draw different parts of the same AVFrame,
      * or multiple AVFrames, and there is no guarantee that slices will be drawn
      * in order.

      * The function is also used by hardware acceleration APIs.
      * It is called at least once during frame decoding to pass
      * the data needed for hardware render.
      * In that mode instead of pixel data, AVFrame points to
      * a structure specific to the acceleration API. The application
      * reads the structure and can change some fields to indicate progress
      * or mark state.

      * - encoding: unused

      * - decoding: Set by user.

      * @param height the height of the slice
      * @param y the y position of the slice
      * @param type 1->top field, 2->bottom field, 3->frame
      * @param offset offset into the AVFrame.data from which the slice should be read

      */

     void (*draw_horiz_band)(struct AVCodecContext *s,

                             const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],

                             int y, int type, int height);

     /* audio only */

     int sample_rate; ///< samples per second

     int channels;    ///< number of audio channels

 
     /**

      * audio sample format
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */

     enum AVSampleFormat sample_fmt;  ///< sample format

     /* The following data should not be initialized. */

     /**

      * Samples per packet, initialized when calling 'init'.

      */
     int frame_size;

     int frame_number;   ///< audio or video frame number
 

     /**

      * Encoding: Number of frames delay there will be from the encoder input to
      *           the decoder output. (we assume the decoder matches the spec)
      * Decoding: Number of frames delay in addition to what a standard decoder
      *           as specified in the spec would produce.

      * - encoding: Set by libavcodec.

      * - decoding: Set by libavcodec.

      */
     int delay;

     /* - encoding parameters */
     float qcompress;  ///< amount of qscale change between easy & hard scenes (0.0-1.0)

     float qblur;      ///< amount of qscale smoothing over time (0.0-1.0)
 

     /**

      * minimum quantizer
      * - encoding: Set by user.

      * - decoding: unused

      */
     int qmin;
 
     /**

      * maximum quantizer
      * - encoding: Set by user.

      * - decoding: unused

      */
     int qmax;
 
     /**

      * maximum quantizer difference between frames
      * - encoding: Set by user.

      * - decoding: unused

      */
     int max_qdiff;
 
     /**

      * maximum number of B-frames between non-B-frames
      * Note: The output will be delayed by max_b_frames+1 relative to the input.
      * - encoding: Set by user.

      * - decoding: unused

      */
     int max_b_frames;
 
     /**

      * qscale factor between IP and B-frames

      * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).

      * - encoding: Set by user.

      * - decoding: unused

      */
     float b_quant_factor;

     /** obsolete FIXME remove */
     int rc_strategy;

 #define FF_RC_STRATEGY_XVID 1
 

     int b_frame_strategy;

     struct AVCodec *codec;

     void *priv_data;
 

     int rtp_payload_size;   /* The size of the RTP payload: the coder will  */

                             /* do its best to deliver a chunk with size     */

                             /* below rtp_payload_size, the chunk will start */

                             /* with a start code on some codecs like H.263. */

                             /* This doesn't take account of any particular  */

                             /* headers inside the transmitted RTP payload.  */

     /* The RTP callback: This function is called    */
     /* every time the encoder has a packet to send. */
     /* It depends on the encoder if the data starts */
     /* with a Start Code (it should). H.263 does.   */
     /* mb_nb contains the number of macroblocks     */
     /* encoded in the RTP payload.                  */

     void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);

     /* statistics, used for 2-pass encoding */
     int mv_bits;
     int header_bits;
     int i_tex_bits;
     int p_tex_bits;
     int i_count;
     int p_count;
     int skip_count;

     int misc_bits;

     /**

      * number of bits used for the previously encoded frame
      * - encoding: Set by libavcodec.

      * - decoding: unused

      */

     int frame_bits;

     /**

      * Private data of the user, can be used to carry app specific stuff.
      * - encoding: Set by user.
      * - decoding: Set by user.

      */
     void *opaque;
 

     char codec_name[32];

     enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */

     enum CodecID codec_id; /* see CODEC_ID_xxx */

     /**
      * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').

      * This is used to work around some encoder bugs.
      * A demuxer should set this to what is stored in the field used to identify the codec.
      * If there are multiple such fields in a container then the demuxer should choose the one
      * which maximizes the information about the used codec.

      * If the codec tag field in a container is larger than 32 bits then the demuxer should

      * remap the longer ID to 32 bits with a table or other structure. Alternatively a new

      * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated

      * first.
      * - encoding: Set by user, if not then the default based on codec_id will be used.
      * - decoding: Set by user, will be converted to uppercase by libavcodec during init.

      */
     unsigned int codec_tag;

     /**

      * Work around bugs in encoders which sometimes cannot be detected automatically.
      * - encoding: Set by user
      * - decoding: Set by user

      */
     int workaround_bugs;

 #define FF_BUG_AUTODETECT       1  ///< autodetection

 #define FF_BUG_OLD_MSMPEG4      2
 #define FF_BUG_XVID_ILACE       4
 #define FF_BUG_UMP4             8
 #define FF_BUG_NO_PADDING       16

 #define FF_BUG_AMV              32

 #define FF_BUG_AC_VLC           0  ///< Will be removed, libavcodec can now handle these non-compliant files by default.

 #define FF_BUG_QPEL_CHROMA      64

 #define FF_BUG_STD_QPEL         128

 #define FF_BUG_QPEL_CHROMA2     256

 #define FF_BUG_DIRECT_BLOCKSIZE 512

 #define FF_BUG_EDGE             1024

 #define FF_BUG_HPEL_CHROMA      2048

 #define FF_BUG_DC_CLIP          4096

 #define FF_BUG_MS               8192 ///< Work around various bugs in Microsoft's broken decoders.

 #define FF_BUG_TRUNCATED       16384

 //#define FF_BUG_FAKE_SCALABILITY 16 //Autodetection should work 100%.

     /**

      * luma single coefficient elimination threshold
      * - encoding: Set by user.

      * - decoding: unused

      */

     int luma_elim_threshold;

     /**

      * chroma single coeff elimination threshold
      * - encoding: Set by user.

      * - decoding: unused

      */

     int chroma_elim_threshold;

     /**

      * strictly follow the standard (MPEG4, ...).
      * - encoding: Set by user.

      * - decoding: Set by user.
      * Setting this to STRICT or higher means the encoder and decoder will

      * generally do stupid things, whereas setting it to unofficial or lower

      * will mean the encoder might produce output that is not supported by all
      * spec-compliant decoders. Decoders don't differentiate between normal,

      * unofficial and experimental (that is, they always try to decode things

      * when they can) unless they are explicitly asked to behave stupidly

      * (=strictly conform to the specs)

      */
     int strict_std_compliance;

 #define FF_COMPLIANCE_VERY_STRICT   2 ///< Strictly conform to an older more strict version of the spec or reference software.

 #define FF_COMPLIANCE_STRICT        1 ///< Strictly conform to all the things in the spec no matter what consequences.

 #define FF_COMPLIANCE_NORMAL        0

 #define FF_COMPLIANCE_UNOFFICIAL   -1 ///< Allow unofficial extensions

 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.

     /**

      * qscale offset between IP and B-frames
      * - encoding: Set by user.

      * - decoding: unused

      */
     float b_quant_offset;

 #if FF_API_ER

     /**

      * Error recognition; higher values will detect more errors but may

      * misdetect some more or less valid parts as errors.

      * - encoding: unused

      * - decoding: Set by user.

      */

     attribute_deprecated int error_recognition;

 #define FF_ER_CAREFUL         1

 #define FF_ER_COMPLIANT       2
 #define FF_ER_AGGRESSIVE      3
 #define FF_ER_VERY_AGGRESSIVE 4

 #define FF_ER_EXPLODE         5

 #endif /* FF_API_ER */

     /**

      * Called at the beginning of each frame to get a buffer for it.

      *
      * The function will set AVFrame.data[], AVFrame.linesize[].
      * AVFrame.extended_data[] must also be set, but it should be the same as
      * AVFrame.data[] except for planar audio with more channels than can fit
      * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
      * many data pointers as it can hold.
      *

      * if CODEC_CAP_DR1 is not set then get_buffer() must call
      * avcodec_default_get_buffer() instead of providing buffers allocated by
      * some other means.

      *
      * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
      * need it. avcodec_default_get_buffer() aligns the output buffer properly,
      * but if get_buffer() is overridden then alignment considerations should
      * be taken into account.
      *
      * @see avcodec_default_get_buffer()
      *
      * Video:
      *
      * If pic.reference is set then the frame will be read later by libavcodec.
      * avcodec_align_dimensions2() should be used to find the required width and
      * height, as they normally need to be rounded up to the next multiple of 16.
      *

      * If frame multithreading is used and thread_safe_callbacks is set,

      * it may be called from a different thread, but not from more than one at
      * once. Does not need to be reentrant.
      *
      * @see release_buffer(), reget_buffer()
      * @see avcodec_align_dimensions2()
      *
      * Audio:
      *
      * Decoders request a buffer of a particular size by setting
      * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
      * however, utilize only part of the buffer by setting AVFrame.nb_samples
      * to a smaller value in the output frame.
      *
      * Decoders cannot use the buffer after returning from
      * avcodec_decode_audio4(), so they will not call release_buffer(), as it
      * is assumed to be released immediately upon return.
      *
      * As a convenience, av_samples_get_buffer_size() and
      * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
      * functions to find the required data size and to fill data pointers and
      * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
      * since all planes must be the same size.
      *
      * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
      *

      * - encoding: unused

      * - decoding: Set by libavcodec, user can override.

      */

     int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);

     /**

      * Called to release buffers which were allocated with get_buffer.

      * A released buffer can be reused in get_buffer().
      * pic.data[*] must be set to NULL.

      * May be called from a different thread if frame multithreading is used,
      * but not by more than one thread at once, so does not need to be reentrant.

      * - encoding: unused

      * - decoding: Set by libavcodec, user can override.

      */

     void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);

     /**

      * Size of the frame reordering buffer in the decoder.

      * For MPEG-2 it is 1 IPB or 0 low delay IP.

      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.

      */
     int has_b_frames;

 
     /**
      * number of bytes per packet if constant and known or 0

      * Used by some WAV based audio codecs.

      */
     int block_align;

 #if FF_API_PARSE_FRAME
     /**
      * If true, only parsing is done. The frame data is returned.
      * Only MPEG audio decoders support this now.
      * - encoding: unused
      * - decoding: Set by user
      */
     attribute_deprecated int parse_only;
 #endif

     /**

      * 0-> h263 quant 1-> mpeg quant
      * - encoding: Set by user.

      * - decoding: unused

      */
     int mpeg_quant;

     /**

      * pass1 encoding statistics output buffer
      * - encoding: Set by libavcodec.

      * - decoding: unused

      */

     char *stats_out;

     /**

      * pass2 encoding statistics input buffer
      * Concatenated stuff from stats_out of pass1 should be placed here.
      * - encoding: Allocated/set/freed by user.

      * - decoding: unused

      */
     char *stats_in;

     /**

      * ratecontrol qmin qmax limiting method
      * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax.
      * - encoding: Set by user.

      * - decoding: unused

      */

     float rc_qsquish;

     float rc_qmod_amp;
     int rc_qmod_freq;

     /**

      * ratecontrol override, see RcOverride
      * - encoding: Allocated/set/freed by user.

      * - decoding: unused

      */

     RcOverride *rc_override;
     int rc_override_count;

     /**

      * rate control equation
      * - encoding: Set by user

      * - decoding: unused

      */

     const char *rc_eq;

     /**

      * maximum bitrate
      * - encoding: Set by user.

      * - decoding: unused

      */

     int rc_max_rate;

     /**

      * minimum bitrate
      * - encoding: Set by user.

      * - decoding: unused

      */

     int rc_min_rate;

     /**

      * decoder bitstream buffer size
      * - encoding: Set by user.

      * - decoding: unused

      */

     int rc_buffer_size;
     float rc_buffer_aggressivity;

 
     /**

      * qscale factor between P and I-frames
      * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
      * - encoding: Set by user.

      * - decoding: unused

      */
     float i_quant_factor;

     /**

      * qscale offset between P and I-frames
      * - encoding: Set by user.

      * - decoding: unused

      */
     float i_quant_offset;

     /**

      * initial complexity for pass1 ratecontrol
      * - encoding: Set by user.

      * - decoding: unused

      */

     float rc_initial_cplx;

     /**

      * DCT algorithm, see FF_DCT_* below
      * - encoding: Set by user.

      * - decoding: unused

      */

     int dct_algo;

 #define FF_DCT_AUTO    0

 #define FF_DCT_FASTINT 1

 #define FF_DCT_INT     2
 #define FF_DCT_MMX     3
 #define FF_DCT_MLIB    4

 #define FF_DCT_ALTIVEC 5

 #define FF_DCT_FAAN    6

     /**

      * luminance masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float lumi_masking;

     /**

      * temporary complexity masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float temporal_cplx_masking;

     /**

      * spatial complexity masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float spatial_cplx_masking;

     /**

      * p block masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float p_masking;

     /**

      * darkness masking (0-> disabled)
      * - encoding: Set by user.

      * - decoding: unused

      */
     float dark_masking;

     /**

      * IDCT algorithm, see FF_IDCT_* below.
      * - encoding: Set by user.
      * - decoding: Set by user.

      */
     int idct_algo;

 #define FF_IDCT_AUTO          0
 #define FF_IDCT_INT           1
 #define FF_IDCT_SIMPLE        2
 #define FF_IDCT_SIMPLEMMX     3
 #define FF_IDCT_LIBMPEG2MMX   4
 #define FF_IDCT_PS2           5
 #define FF_IDCT_MLIB          6
 #define FF_IDCT_ARM           7
 #define FF_IDCT_ALTIVEC       8
 #define FF_IDCT_SH4           9
 #define FF_IDCT_SIMPLEARM     10
 #define FF_IDCT_H264          11
 #define FF_IDCT_VP3           12
 #define FF_IDCT_IPP           13
 #define FF_IDCT_XVIDMMX       14
 #define FF_IDCT_CAVS          15

 #define FF_IDCT_SIMPLEARMV5TE 16

 #define FF_IDCT_SIMPLEARMV6   17

 #define FF_IDCT_SIMPLEVIS     18

 #define FF_IDCT_WMV2          19

 #define FF_IDCT_FAAN          20

 #define FF_IDCT_EA            21

 #define FF_IDCT_SIMPLENEON    22

 #define FF_IDCT_SIMPLEALPHA   23

 #define FF_IDCT_BINK          24

     /**

      * slice count
      * - encoding: Set by libavcodec.
      * - decoding: Set by user (or 0).

      */
     int slice_count;
     /**

      * slice offsets in the frame in bytes
      * - encoding: Set/allocated by libavcodec.
      * - decoding: Set/allocated by user (or NULL).

      */
     int *slice_offset;
 

     /**

      * error concealment flags

      * - encoding: unused

      * - decoding: Set by user.

      */
     int error_concealment;
 #define FF_EC_GUESS_MVS   1
 #define FF_EC_DEBLOCK     2
 

     /**

      * dsp_mask could be add used to disable unwanted CPU features

      * CPU features (i.e. MMX, SSE. ...)

      *

      * With the FORCE flag you may instead enable given CPU features.
      * (Dangerous: Usable in case of misdetection, improper usage however will
      * result into program crash.)

      */
     unsigned dsp_mask;

     /**

      * bits per sample/pixel from the demuxer (needed for huffyuv).

      * - encoding: Set by libavcodec.
      * - decoding: Set by user.

      */

      int bits_per_coded_sample;

     /**

      * prediction method (needed for huffyuv)
      * - encoding: Set by user.

      * - decoding: unused

      */
      int prediction_method;
 #define FF_PRED_LEFT   0
 #define FF_PRED_PLANE  1
 #define FF_PRED_MEDIAN 2

     /**

      * sample aspect ratio (0 if unknown)

      * That is the width of a pixel divided by the height of the pixel.

      * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */

     AVRational sample_aspect_ratio;

 
     /**

      * the picture in the bitstream
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.

      */

     AVFrame *coded_frame;

 
     /**

      * debug
      * - encoding: Set by user.
      * - decoding: Set by user.

      */
     int debug;

 #define FF_DEBUG_PICT_INFO   1
 #define FF_DEBUG_RC          2
 #define FF_DEBUG_BITSTREAM   4
 #define FF_DEBUG_MB_TYPE     8
 #define FF_DEBUG_QP          16
 #define FF_DEBUG_MV          32
 #define FF_DEBUG_DCT_COEFF   0x00000040
 #define FF_DEBUG_SKIP        0x00000080
 #define FF_DEBUG_STARTCODE   0x00000100
 #define FF_DEBUG_PTS         0x00000200
 #define FF_DEBUG_ER          0x00000400
 #define FF_DEBUG_MMCO        0x00000800
 #define FF_DEBUG_BUGS        0x00001000
 #define FF_DEBUG_VIS_QP      0x00002000

 #define FF_DEBUG_VIS_MB_TYPE 0x00004000

 #define FF_DEBUG_BUFFERS     0x00008000

 #define FF_DEBUG_THREADS     0x00010000

     /**

      * debug
      * - encoding: Set by user.
      * - decoding: Set by user.

      */
     int debug_mv;
 #define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
 #define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
 
     /**

      * error
      * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.

      * - decoding: unused

      */

     uint64_t error[AV_NUM_DATA_POINTERS];

     /**

      * motion estimation comparison function
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_cmp;
     /**

      * subpixel motion estimation comparison function
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_sub_cmp;
     /**

      * macroblock comparison function (not supported yet)
      * - encoding: Set by user.

      * - decoding: unused

      */
     int mb_cmp;

     /**

      * interlaced DCT comparison function
      * - encoding: Set by user.

      * - decoding: unused
      */
     int ildct_cmp;

 #define FF_CMP_SAD    0
 #define FF_CMP_SSE    1
 #define FF_CMP_SATD   2
 #define FF_CMP_DCT    3
 #define FF_CMP_PSNR   4
 #define FF_CMP_BIT    5
 #define FF_CMP_RD     6
 #define FF_CMP_ZERO   7
 #define FF_CMP_VSAD   8
 #define FF_CMP_VSSE   9
 #define FF_CMP_NSSE   10
 #define FF_CMP_W53    11
 #define FF_CMP_W97    12

 #define FF_CMP_DCTMAX 13

 #define FF_CMP_DCT264 14

 #define FF_CMP_CHROMA 256

     /**

      * ME diamond size & shape
      * - encoding: Set by user.

      * - decoding: unused

      */
     int dia_size;

 
     /**

      * amount of previous MV predictors (2a+1 x 2a+1 square)
      * - encoding: Set by user.

      * - decoding: unused

      */
     int last_predictor_count;

     /**

      * prepass for motion estimation
      * - encoding: Set by user.

      * - decoding: unused

      */
     int pre_me;

     /**

      * motion estimation prepass comparison function
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_pre_cmp;

     /**

      * ME prepass diamond size & shape
      * - encoding: Set by user.

      * - decoding: unused

      */
     int pre_dia_size;
 

     /**

      * subpel ME quality
      * - encoding: Set by user.

      * - decoding: unused

      */
     int me_subpel_quality;
 

     /**

      * callback to negotiate the pixelFormat

      * @param fmt is the list of formats which are supported by the codec,

      * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
      * The first is always the native one.
      * @return the chosen format

      * - encoding: unused

      * - decoding: Set by user, if not set the native format will be chosen.

      */

     enum PixelFormat (*get_format)(struct AVCodecContext *s, const enum PixelFormat * fmt);

 
     /**

      * DTG active format information (additional aspect ratio
      * information only used in DVB MPEG-2 transport streams)
      * 0 if not set.

      *

      * - encoding: unused
      * - decoding: Set by decoder.

      */
     int dtg_active_format;
 #define FF_DTG_AFD_SAME         8
 #define FF_DTG_AFD_4_3          9
 #define FF_DTG_AFD_16_9         10
 #define FF_DTG_AFD_14_9         11
 #define FF_DTG_AFD_4_3_SP_14_9  13
 #define FF_DTG_AFD_16_9_SP_14_9 14
 #define FF_DTG_AFD_SP_4_3       15
 

     /**

      * maximum motion estimation search range in subpel units
      * If 0 then no limit.

      *

      * - encoding: Set by user.
      * - decoding: unused

      */

     int me_range;

     /**

      * intra quantizer bias
      * - encoding: Set by user.

      * - decoding: unused
      */
     int intra_quant_bias;
 #define FF_DEFAULT_QUANT_BIAS 999999

     /**

      * inter quantizer bias
      * - encoding: Set by user.

      * - decoding: unused
      */
     int inter_quant_bias;

 
     /**

      * color table ID
      * - encoding: unused
      * - decoding: Which clrtable should be used for 8bit RGB images.
      *             Tables have to be stored somewhere. FIXME

      */
     int color_table_id;

 #if FF_API_INTERNAL_CONTEXT

     /**

      * internal_buffer count
      * Don't touch, used by libavcodec default_get_buffer().

      * @deprecated this field was moved to an internal context

      */

     attribute_deprecated int internal_buffer_count;

     /**

      * internal_buffers
      * Don't touch, used by libavcodec default_get_buffer().

      * @deprecated this field was moved to an internal context

      */

     attribute_deprecated void *internal_buffer;
 #endif

     /**

      * Global quality for codecs which cannot change it per frame.
      * This should be proportional to MPEG-1/2/4 qscale.
      * - encoding: Set by user.

      * - decoding: unused
      */
     int global_quality;

 #define FF_CODER_TYPE_VLC       0
 #define FF_CODER_TYPE_AC        1

 #define FF_CODER_TYPE_RAW       2
 #define FF_CODER_TYPE_RLE       3
 #define FF_CODER_TYPE_DEFLATE   4

     /**
      * coder type

      * - encoding: Set by user.

      * - decoding: unused
      */
     int coder_type;
 
     /**
      * context model

      * - encoding: Set by user.

      * - decoding: unused
      */
     int context_model;

 #if 0
     /**
      *
      * - encoding: unused

      * - decoding: Set by user.

      */
     uint8_t * (*realloc)(struct AVCodecContext *s, uint8_t *buf, int buf_size);
 #endif

     /**
      * slice flags
      * - encoding: unused

      * - decoding: Set by user.

      */
     int slice_flags;
 #define SLICE_FLAG_CODED_ORDER    0x0001 ///< draw_horiz_band() is called in coded order instead of display
 #define SLICE_FLAG_ALLOW_FIELD    0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
 #define SLICE_FLAG_ALLOW_PLANE    0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
 

     /**
      * XVideo Motion Acceleration
      * - encoding: forbidden
      * - decoding: set by decoder
      */
     int xvmc_acceleration;

     /**
      * macroblock decision mode

      * - encoding: Set by user.

      * - decoding: unused
      */
     int mb_decision;
 #define FF_MB_DECISION_SIMPLE 0        ///< uses mb_cmp
 #define FF_MB_DECISION_BITS   1        ///< chooses the one which needs the fewest bits

 #define FF_MB_DECISION_RD     2        ///< rate distortion

 
     /**
      * custom intra quantization matrix

      * - encoding: Set by user, can be NULL.
      * - decoding: Set by libavcodec.

      */
     uint16_t *intra_matrix;
 
     /**
      * custom inter quantization matrix

      * - encoding: Set by user, can be NULL.
      * - decoding: Set by libavcodec.

      */
     uint16_t *inter_matrix;

     /**
      * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').

      * This is used to work around some encoder bugs.

      * - encoding: unused

      * - decoding: Set by user, will be converted to uppercase by libavcodec during init.

      */
     unsigned int stream_codec_tag;

 
     /**

      * scene change detection threshold
      * 0 is default, larger means fewer detected scene changes.
      * - encoding: Set by user.

      * - decoding: unused
      */
     int scenechange_threshold;

 
     /**

      * minimum Lagrange multipler
      * - encoding: Set by user.

      * - decoding: unused
      */
     int lmin;
 
     /**

      * maximum Lagrange multipler
      * - encoding: Set by user.

      * - decoding: unused
      */
     int lmax;

 #if FF_API_PALETTE_CONTROL

     /**

      * palette control structure

      * - encoding: ??? (no palette-enabled encoder yet)

      * - decoding: Set by user.

      */
     struct AVPaletteControl *palctrl;

 #endif

 
     /**
      * noise reduction strength

      * - encoding: Set by user.

      * - decoding: unused
      */
     int noise_reduction;

     /**

      * Called at the beginning of a frame to get cr buffer for it.
      * Buffer type (size, hints) must be the same. libavcodec won't check it.
      * libavcodec will pass previous buffer in pic, function should return

      * same buffer or new buffer with old frame "painted" into it.

      * If pic.data[0] == NULL must behave like get_buffer().

      * if CODEC_CAP_DR1 is not set then reget_buffer() must call
      * avcodec_default_reget_buffer() instead of providing buffers allocated by
      * some other means.

      * - encoding: unused

      * - decoding: Set by libavcodec, user can override.

      */

     int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);

 
     /**

      * Number of bits which should be loaded into the rc buffer before decoding starts.
      * - encoding: Set by user.

      * - decoding: unused
      */
     int rc_initial_buffer_occupancy;
 
     /**
      *

      * - encoding: Set by user.

      * - decoding: unused
      */
     int inter_threshold;
 
     /**

      * CODEC_FLAG2_*
      * - encoding: Set by user.
      * - decoding: Set by user.

      */
     int flags2;

 
     /**

      * Simulates errors in the bitstream to test error concealment.
      * - encoding: Set by user.
      * - decoding: unused

      */
     int error_rate;

 #if FF_API_ANTIALIAS_ALGO

     /**
      * MP3 antialias algorithm, see FF_AA_* below.
      * - encoding: unused

      * - decoding: Set by user.

      */

     attribute_deprecated int antialias_algo;

 #define FF_AA_AUTO    0
 #define FF_AA_FASTINT 1 //not implemented yet
 #define FF_AA_INT     2
 #define FF_AA_FLOAT   3

 #endif
 

     /**

      * quantizer noise shaping
      * - encoding: Set by user.

      * - decoding: unused
      */
     int quantizer_noise_shaping;

 
     /**

      * thread count

      * is used to decide how many independent tasks should be passed to execute()

      * - encoding: Set by user.
      * - decoding: Set by user.

      */
     int thread_count;

     /**

      * The codec may call this to execute several independent things.
      * It will return only after finishing all tasks.
      * The user may replace this with some multithreaded implementation,
      * the default implementation will execute the parts serially.

      * @param count the number of things to execute

      * - encoding: Set by libavcodec, user can override.
      * - decoding: Set by libavcodec, user can override.

      */

     int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);

     /**

      * thread opaque
      * Can be used by execute() to store some per AVCodecContext stuff.

      * - encoding: set by execute()
      * - decoding: set by execute()
      */
     void *thread_opaque;

 
     /**

      * Motion estimation threshold below which no motion estimation is
      * performed, but instead the user specified motion vectors are used.

      *

      * - encoding: Set by user.

      * - decoding: unused

      */

      int me_threshold;

 
     /**

      * Macroblock threshold below which the user specified macroblock types will be used.
      * - encoding: Set by user.

      * - decoding: unused
      */
      int mb_threshold;

 
     /**

      * precision of the intra DC coefficient - 8
      * - encoding: Set by user.

      * - decoding: unused
      */
      int intra_dc_precision;

 
     /**

      * noise vs. sse weight for the nsse comparsion function
      * - encoding: Set by user.

      * - decoding: unused
      */
      int nsse_weight;

 
     /**

      * Number of macroblock rows at the top which are skipped.

      * - encoding: unused

      * - decoding: Set by user.

      */
      int skip_top;
 
     /**

      * Number of macroblock rows at the bottom which are skipped.

      * - encoding: unused

      * - decoding: Set by user.

      */
      int skip_bottom;

 
     /**
      * profile

      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
      int profile;
 #define FF_PROFILE_UNKNOWN -99

 #define FF_PROFILE_RESERVED -100

 #define FF_PROFILE_AAC_MAIN 0

 #define FF_PROFILE_AAC_LOW  1
 #define FF_PROFILE_AAC_SSR  2
 #define FF_PROFILE_AAC_LTP  3

 #define FF_PROFILE_DTS         20
 #define FF_PROFILE_DTS_ES      30
 #define FF_PROFILE_DTS_96_24   40
 #define FF_PROFILE_DTS_HD_HRA  50
 #define FF_PROFILE_DTS_HD_MA   60
 

 #define FF_PROFILE_MPEG2_422    0
 #define FF_PROFILE_MPEG2_HIGH   1
 #define FF_PROFILE_MPEG2_SS     2
 #define FF_PROFILE_MPEG2_SNR_SCALABLE  3
 #define FF_PROFILE_MPEG2_MAIN   4
 #define FF_PROFILE_MPEG2_SIMPLE 5
 

 #define FF_PROFILE_H264_CONSTRAINED  (1<<9)  // 8+1; constraint_set1_flag
 #define FF_PROFILE_H264_INTRA        (1<<11) // 8+3; constraint_set3_flag
 
 #define FF_PROFILE_H264_BASELINE             66
 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
 #define FF_PROFILE_H264_MAIN                 77
 #define FF_PROFILE_H264_EXTENDED             88
 #define FF_PROFILE_H264_HIGH                 100
 #define FF_PROFILE_H264_HIGH_10              110
 #define FF_PROFILE_H264_HIGH_10_INTRA        (110|FF_PROFILE_H264_INTRA)
 #define FF_PROFILE_H264_HIGH_422             122
 #define FF_PROFILE_H264_HIGH_422_INTRA       (122|FF_PROFILE_H264_INTRA)

 #define FF_PROFILE_H264_HIGH_444             144

 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE  244
 #define FF_PROFILE_H264_HIGH_444_INTRA       (244|FF_PROFILE_H264_INTRA)
 #define FF_PROFILE_H264_CAVLC_444            44

 #define FF_PROFILE_VC1_SIMPLE   0
 #define FF_PROFILE_VC1_MAIN     1
 #define FF_PROFILE_VC1_COMPLEX  2
 #define FF_PROFILE_VC1_ADVANCED 3
 

 #define FF_PROFILE_MPEG4_SIMPLE                     0
 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE            1
 #define FF_PROFILE_MPEG4_CORE                       2
 #define FF_PROFILE_MPEG4_MAIN                       3
 #define FF_PROFILE_MPEG4_N_BIT                      4
 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE           5
 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION      6
 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE     7
 #define FF_PROFILE_MPEG4_HYBRID                     8
 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME         9
 #define FF_PROFILE_MPEG4_CORE_SCALABLE             10
 #define FF_PROFILE_MPEG4_ADVANCED_CODING           11
 #define FF_PROFILE_MPEG4_ADVANCED_CORE             12
 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO             14
 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE           15
 

     /**
      * level

      * - encoding: Set by user.
      * - decoding: Set by libavcodec.

      */
      int level;
 #define FF_LEVEL_UNKNOWN -99

 
     /**

      * low resolution decoding, 1-> 1/2 size, 2->1/4 size

      * - encoding: unused

      * - decoding: Set by user.

      */
      int lowres;

 
     /**

      * Bitstream width / height, may be different from width/height if lowres enabled.

      * - encoding: unused

      * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.

      */
     int coded_width, coded_height;

 
     /**
      * frame skip threshold

      * - encoding: Set by user.

      * - decoding: unused
      */
     int frame_skip_threshold;
 
     /**
      * frame skip factor

      * - encoding: Set by user.

      * - decoding: unused
      */
     int frame_skip_factor;

 
     /**
      * frame skip exponent

      * - encoding: Set by user.

      * - decoding: unused
      */
     int frame_skip_exp;
 
     /**

      * frame skip comparison function
      * - encoding: Set by user.

      * - decoding: unused
      */
     int frame_skip_cmp;

 
     /**

      * Border processing masking, raises the quantizer for mbs on the borders

      * of the picture.

      * - encoding: Set by user.

      * - decoding: unused
      */
     float border_masking;

 
     /**

      * minimum MB lagrange multipler
      * - encoding: Set by user.

      * - decoding: unused
      */
     int mb_lmin;
 
     /**

      * maximum MB lagrange multipler
      * - encoding: Set by user.

      * - decoding: unused
      */
     int mb_lmax;

 
     /**

      *

      * - encoding: Set by user.

      * - decoding: unused
      */
     int me_penalty_compensation;

 
     /**

      *

      * - encoding: unused

      * - decoding: Set by user.

      */
     enum AVDiscard skip_loop_filter;
 
     /**

      *

      * - encoding: unused

      * - decoding: Set by user.

      */
     enum AVDiscard skip_idct;
 
     /**

      *

      * - encoding: unused

      * - decoding: Set by user.

      */
     enum AVDiscard skip_frame;

 
     /**
      *

      * - encoding: Set by user.

      * - decoding: unused
      */
     int bidir_refine;

 
     /**
      *

      * - encoding: Set by user.

      * - decoding: unused
      */
     int brd_scale;

 #if FF_API_X264_GLOBAL_OPTS

     /**
      * constant rate factor - quality-based VBR - values ~correspond to qps

      * - encoding: Set by user.

      * - decoding: unused

      *   @deprecated use 'crf' libx264 private option

      */

     attribute_deprecated float crf;

 
     /**
      * constant quantization parameter rate control method

      * - encoding: Set by user.

      * - decoding: unused

      *   @deprecated use 'cqp' libx264 private option

      */

     attribute_deprecated int cqp;
 #endif

 
     /**

      * minimum GOP size
      * - encoding: Set by user.

      * - decoding: unused
      */
     int keyint_min;
 
     /**
      * number of reference frames

      * - encoding: Set by user.

      * - decoding: Set by lavc.

      */
     int refs;
 
     /**
      * chroma qp offset from luma

      * - encoding: Set by user.

      * - decoding: unused
      */
     int chromaoffset;
 

 #if FF_API_X264_GLOBAL_OPTS

     /**

      * Influences how often B-frames are used.
      * - encoding: Set by user.

      * - decoding: unused
      */

     attribute_deprecated int bframebias;
 #endif

 
     /**
      * trellis RD quantization

      * - encoding: Set by user.

      * - decoding: unused
      */
     int trellis;
 

 #if FF_API_X264_GLOBAL_OPTS

     /**

      * Reduce fluctuations in qp (before curve compression).
      * - encoding: Set by user.

      * - decoding: unused
      */

     attribute_deprecated float complexityblur;

 
     /**
      * in-loop deblocking filter alphac0 parameter
      * alpha is in the range -6...6

      * - encoding: Set by user.

      * - decoding: unused
      */

     attribute_deprecated int deblockalpha;

 
     /**
      * in-loop deblocking filter beta parameter
      * beta is in the range -6...6

      * - encoding: Set by user.

      * - decoding: unused
      */

     attribute_deprecated int deblockbeta;

 
     /**
      * macroblock subpartition sizes to consider - p8x8, p4x4, b8x8, i8x8, i4x4

      * - encoding: Set by user.

      * - decoding: unused
      */

     attribute_deprecated int partitions;

 #define X264_PART_I4X4 0x001  /* Analyze i4x4 */
 #define X264_PART_I8X8 0x002  /* Analyze i8x8 (requires 8x8 transform) */
 #define X264_PART_P8X8 0x010  /* Analyze p16x8, p8x16 and p8x8 */
 #define X264_PART_P4X4 0x020  /* Analyze p8x4, p4x8, p4x4 */
 #define X264_PART_B8X8 0x100  /* Analyze b16x8, b8x16 and b8x8 */

 
     /**

      * direct MV prediction mode - 0 (none), 1 (spatial), 2 (temporal), 3 (auto)

      * - encoding: Set by user.

      * - decoding: unused
      */

     attribute_deprecated int directpred;
 #endif

     /**

      * Audio cutoff bandwidth (0 means "automatic")

      * - encoding: Set by user.

      * - decoding: unused
      */
     int cutoff;

 
     /**

      * Multiplied by qscale for each frame and added to scene_change_score.
      * - encoding: Set by user.

      * - decoding: unused
      */
     int scenechange_factor;

 
     /**
      *

      * Note: Value depends upon the compare function used for fullpel ME.
      * - encoding: Set by user.

      * - decoding: unused
      */
     int mv0_threshold;

 
     /**

      * Adjusts sensitivity of b_frame_strategy 1.
      * - encoding: Set by user.

      * - decoding: unused
      */
     int b_sensitivity;

 
     /**

      * - encoding: Set by user.

      * - decoding: unused
      */
     int compression_level;
 #define FF_COMPRESSION_DEFAULT -1
 
     /**

      * - encoding: Set by user.
      * - decoding: unused

      */

     int min_prediction_order;

 
     /**

      * - encoding: Set by user.
      * - decoding: unused

      */

     int max_prediction_order;
 
 #if FF_API_FLAC_GLOBAL_OPTS
     /**

      * @name FLAC options

      * @deprecated Use FLAC encoder private options instead.
      * @{
      */

 
     /**

      * LPC coefficient precision - used by FLAC encoder

      * - encoding: Set by user.
      * - decoding: unused

      */

     attribute_deprecated int lpc_coeff_precision;

 
     /**
      * search method for selecting prediction order

      * - encoding: Set by user.
      * - decoding: unused

      */

     attribute_deprecated int prediction_order_method;

 
     /**

      * - encoding: Set by user.
      * - decoding: unused

      */

     attribute_deprecated int min_partition_order;

 
     /**

      * - encoding: Set by user.
      * - decoding: unused

      */

     attribute_deprecated int max_partition_order;
     /**
      * @}
      */
 #endif

 
     /**

      * GOP timecode frame start number
      * - encoding: Set by user, in non drop frame format
      * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)

      */
     int64_t timecode_frame_start;

 #if FF_API_REQUEST_CHANNELS

     /**

      * Decoder should decode to this many channels if it can (0 for default)
      * - encoding: unused
      * - decoding: Set by user.

      * @deprecated Deprecated in favor of request_channel_layout.

      */
     int request_channels;

 #endif

 #if FF_API_DRC_SCALE

     /**
      * Percentage of dynamic range compression to be applied by the decoder.
      * The default value is 1.0, corresponding to full compression.
      * - encoding: unused
      * - decoding: Set by user.

      * @deprecated use AC3 decoder private option instead.

      */

     attribute_deprecated float drc_scale;
 #endif

 
     /**
      * opaque 64bit number (generally a PTS) that will be reordered and
      * output in AVFrame.reordered_opaque

      * @deprecated in favor of pkt_pts

      * - encoding: unused
      * - decoding: Set by user.
      */
     int64_t reordered_opaque;

 
     /**
      * Bits per sample/pixel of internal libavcodec pixel/sample format.
      * - encoding: set by user.
      * - decoding: set by libavcodec.
      */
     int bits_per_raw_sample;

 
     /**
      * Audio channel layout.
      * - encoding: set by user.

      * - decoding: set by user, may be overwritten by libavcodec.

      */

     uint64_t channel_layout;

 
     /**
      * Request decoder to use this channel layout if it can (0 for default)
      * - encoding: unused
      * - decoding: Set by user.
      */

     uint64_t request_channel_layout;

 
     /**
      * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
      * - encoding: Set by user.
      * - decoding: unused.
      */
     float rc_max_available_vbv_use;
 
     /**
      * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
      * - encoding: Set by user.
      * - decoding: unused.
      */
     float rc_min_vbv_overflow_use;

 
     /**
      * Hardware accelerator in use
      * - encoding: unused.
      * - decoding: Set by libavcodec
      */
     struct AVHWAccel *hwaccel;

 
     /**
      * For some codecs, the time base is closer to the field rate than the frame rate.
      * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
      * if no telecine is used ...
      *
      * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
      */
     int ticks_per_frame;

 
     /**
      * Hardware accelerator context.
      * For some hardware accelerators, a global context needs to be
      * provided by the user. In that case, this holds display-dependent
      * data FFmpeg cannot instantiate itself. Please refer to the
      * FFmpeg HW accelerator documentation to know how to fill this
      * is. e.g. for VA API, this is a struct vaapi_context.
      * - encoding: unused
      * - decoding: Set by user
      */
     void *hwaccel_context;

 
     /**
      * Chromaticity coordinates of the source primaries.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorPrimaries color_primaries;
 
     /**
      * Color Transfer Characteristic.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorTransferCharacteristic color_trc;
 
     /**
      * YUV colorspace type.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorSpace colorspace;
 
     /**
      * MPEG vs JPEG YUV range.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */
     enum AVColorRange color_range;

 
     /**
      * This defines the location of chroma samples.
      * - encoding: Set by user
      * - decoding: Set by libavcodec
      */

     enum AVChromaLocation chroma_sample_location;

 
     /**
      * The codec may call this to execute several independent things.
      * It will return only after finishing all tasks.
      * The user may replace this with some multithreaded implementation,
      * the default implementation will execute the parts serially.
      * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
      * @param c context passed also to func
      * @param count the number of things to execute
      * @param arg2 argument passed unchanged to func
      * @param ret return values of executed functions, must have space for "count" values. May be NULL.
      * @param func function that will be called count times, with jobnr from 0 to count-1.
      *             threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
      *             two instances of func executing at the same time will have the same threadnr.
      * @return always 0 currently, but code should handle a future improvement where when any call to func
      *         returns < 0 no further calls to func may be done and < 0 is returned.
      * - encoding: Set by libavcodec, user can override.
      * - decoding: Set by libavcodec, user can override.
      */
     int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);

 #if FF_API_X264_GLOBAL_OPTS

     /**
      * explicit P-frame weighted prediction analysis method
      * 0: off
      * 1: fast blind weighting (one reference duplicate with -1 offset)
      * 2: smart weighting (full fade detection analysis)
      * - encoding: Set by user.
      * - decoding: unused
      */

     attribute_deprecated int weighted_p_pred;

 
     /**
      * AQ mode
      * 0: Disabled
      * 1: Variance AQ (complexity mask)
      * 2: Auto-variance AQ (experimental)
      * - encoding: Set by user
      * - decoding: unused
      */

     attribute_deprecated int aq_mode;

 
     /**
      * AQ strength
      * Reduces blocking and blurring in flat and textured areas.
      * - encoding: Set by user
      * - decoding: unused
      */

     attribute_deprecated float aq_strength;

 
     /**
      * PSY RD
      * Strength of psychovisual optimization
      * - encoding: Set by user
      * - decoding: unused
      */

     attribute_deprecated float psy_rd;

 
     /**
      * PSY trellis
      * Strength of psychovisual optimization
      * - encoding: Set by user
      * - decoding: unused
      */

     attribute_deprecated float psy_trellis;

 
     /**
      * RC lookahead
      * Number of frames for frametype and ratecontrol lookahead
      * - encoding: Set by user
      * - decoding: unused
      */

     attribute_deprecated int rc_lookahead;

 
     /**
      * Constant rate factor maximum
      * With CRF encoding mode and VBV restrictions enabled, prevents quality from being worse
      * than crf_max, even if doing so would violate VBV restrictions.
      * - encoding: Set by user.
      * - decoding: unused
      */

     attribute_deprecated float crf_max;
 #endif

 
     int log_level_offset;

 #if FF_API_FLAC_GLOBAL_OPTS

     /**
      * Determines which LPC analysis algorithm to use.
      * - encoding: Set by user
      * - decoding: unused
      */

     attribute_deprecated enum AVLPCType lpc_type;

 
     /**
      * Number of passes to use for Cholesky factorization during LPC analysis
      * - encoding: Set by user
      * - decoding: unused
      */

     attribute_deprecated int lpc_passes;
 #endif

 
     /**
      * Number of slices.
      * Indicates number of picture subdivisions. Used for parallelized
      * decoding.
      * - encoding: Set by user
      * - decoding: unused
      */
     int slices;

 
     /**
      * Header containing style information for text subtitles.
      * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
      * [Script Info] and [V4+ Styles] section, plus the [Events] line and
      * the Format line following. It shouldn't include any Dialogue line.

      * - encoding: Set/allocated/freed by user (before avcodec_open2())
      * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())

      */
     uint8_t *subtitle_header;
     int subtitle_header_size;

 
     /**
      * Current packet as passed into the decoder, to avoid having
      * to pass the packet into every function. Currently only valid
      * inside lavc and get/release_buffer callbacks.
      * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
      * - encoding: unused
      */
     AVPacket *pkt;

 #if FF_API_INTERNAL_CONTEXT

     /**

      * Whether this is a copy of the context which had init() called on it.
      * This is used by multithreading - shared tables and picture pointers
      * should be freed from the original context only.
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.

      *
      * @deprecated this field has been moved to an internal context

      */

     attribute_deprecated int is_copy;
 #endif

 
     /**
      * Which multithreading methods to use.
      * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
      * so clients which cannot provide future frames should not use it.
      *
      * - encoding: Set by user, otherwise the default is used.
      * - decoding: Set by user, otherwise the default is used.
      */
     int thread_type;

 #define FF_THREAD_FRAME   1 ///< Decode more than one frame at once
 #define FF_THREAD_SLICE   2 ///< Decode more than one part of a single frame at once

 
     /**
      * Which multithreading methods are in use by the codec.
      * - encoding: Set by libavcodec.
      * - decoding: Set by libavcodec.
      */
     int active_thread_type;
 
     /**
      * Set by the client if its custom get_buffer() callback can be called
      * from another thread, which allows faster multithreaded decoding.
      * draw_horiz_band() will be called from other threads regardless of this setting.
      * Ignored if the default get_buffer() is used.
      * - encoding: Set by user.
      * - decoding: Set by user.
      */
     int thread_safe_callbacks;
 
     /**

      * VBV delay coded in the last frame (in periods of a 27 MHz clock).
      * Used for compliant TS muxing.
      * - encoding: Set by libavcodec.
      * - decoding: unused.
      */
     uint64_t vbv_delay;
 
     /**

      * Type of service that the audio stream conveys.
      * - encoding: Set by user.
      * - decoding: Set by libavcodec.
      */
     enum AVAudioServiceType audio_service_type;

 
     /**

      * desired sample format
      * - encoding: Not used.

      * - decoding: Set by user.

      * Decoder will decode to this format if it can.

      */
     enum AVSampleFormat request_sample_fmt;

 
     /**

      * Error recognition; may misdetect some more or less valid parts as errors.
      * - encoding: unused
      * - decoding: Set by user.
      */

     int err_recognition;

 #define AV_EF_CRCCHECK  (1<<0)
 #define AV_EF_BITSTREAM (1<<1)
 #define AV_EF_BUFFER    (1<<2)
 #define AV_EF_EXPLODE   (1<<3)

 #define AV_EF_CAREFUL    (1<<16)
 #define AV_EF_COMPLIANT  (1<<17)
 #define AV_EF_AGGRESSIVE (1<<18)
 

     /**

      * Private context used for internal data.
      *
      * Unlike priv_data, this is not codec-specific. It is used in general
      * libavcodec functions.
      */
     struct AVCodecInternal *internal;

 
     /**

      * Current statistics for PTS correction.

      * - decoding: maintained and used by libavcodec, not intended to be used by user apps

      * - encoding: unused
      */
     int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
     int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
     int64_t pts_correction_last_pts;       /// PTS of the last frame
     int64_t pts_correction_last_dts;       /// DTS of the last frame
 

 } AVCodecContext;
 

 /**

  * AVProfile.
  */
 typedef struct AVProfile {
     int profile;
     const char *name; ///< short name for the profile
 } AVProfile;
 

 typedef struct AVCodecDefault AVCodecDefault;
 

 /**

  * AVCodec.
  */

 typedef struct AVCodec {

     /**
      * Name of the codec implementation.
      * The name is globally unique among encoders and among decoders (but an
      * encoder and a decoder can share the same name).
      * This is the primary way to find a codec from the user perspective.
      */