/*

  * Interface to xvidcore for MPEG-4 encoding

  * Copyright (c) 2004 Adam Thayer <krevnik@comcast.net>
  *

  * 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

  */

 /**

  * @file

  * Interface to xvidcore for MPEG-4 compliant encoding.
  * @author Adam Thayer (krevnik@comcast.net)
  */

 #include <stdio.h>
 #include <string.h>

 #include <xvid.h>

 #include "libavutil/avassert.h"

 #include "libavutil/cpu.h"

 #include "libavutil/file.h"

 #include "libavutil/internal.h"

 #include "libavutil/intreadwrite.h"

 #include "libavutil/mathematics.h"

 #include "libavutil/mem.h"

 #include "libavutil/opt.h"

 
 #include "avcodec.h"

 #include "internal.h"

 #include "libxvid.h"

 #include "mpegutils.h"

 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif
 

 #if HAVE_IO_H
 #include <io.h>
 #endif
 

 /**
  * Buffer management macros.
  */

 #define BUFFER_SIZE         1024
 #define BUFFER_REMAINING(x) (BUFFER_SIZE - strlen(x))
 #define BUFFER_CAT(x)       (&((x)[strlen(x)]))

 
 /**

  * Structure for the private Xvid context.

  * This stores all the private context for the codec.
  */

 struct xvid_context {

     AVClass *class;

     void *encoder_handle;          /**< Handle for Xvid encoder */
     int xsize;                     /**< Frame x size */
     int ysize;                     /**< Frame y size */
     int vop_flags;                 /**< VOP flags for Xvid encoder */
     int vol_flags;                 /**< VOL flags for Xvid encoder */
     int me_flags;                  /**< Motion Estimation flags */
     int qscale;                    /**< Do we use constant scale? */
     int quicktime_format;          /**< Are we in a QT-based format? */
     char *twopassbuffer;           /**< Character buffer for two-pass */
     char *old_twopassbuffer;       /**< Old character buffer (two-pass) */
     char *twopassfile;             /**< second pass temp file name */

     int twopassfd;

     unsigned char *intra_matrix;   /**< P-Frame Quant Matrix */
     unsigned char *inter_matrix;   /**< I-Frame Quant Matrix */

     int lumi_aq;                   /**< Lumi masking as an aq method */
     int variance_aq;               /**< Variance adaptive quantization */

     int ssim;                      /**< SSIM information display mode */
     int ssim_acc;                  /**< SSIM accuracy. 0: accurate. 4: fast. */

     int gmc;

     int me_quality;                /**< Motion estimation quality. 0: fast 6: best. */

     int mpeg_quant;                /**< Quantization type. 0: H.263, 1: MPEG */

 };

 /**
  * Structure for the private first-pass plugin.
  */

 struct xvid_ff_pass1 {

     int version;                    /**< Xvid version */

     struct xvid_context *context;   /**< Pointer to private context */

 };

 static int xvid_encode_close(AVCodecContext *avctx);

 static int xvid_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                              const AVFrame *picture, int *got_packet);
 

 /*
  * Xvid 2-Pass Kludge Section
  *
  * Xvid's default 2-pass doesn't allow us to create data as we need to, so
  * this section spends time replacing the first pass plugin so we can write
  * statistic information as libavcodec requests in. We have another kludge
  * that allows us to pass data to the second pass in Xvid without a custom
  * rate-control plugin.
  */

 
 /**

  * Initialize the two-pass plugin and context.
  *
  * @param param Input construction parameter structure
  * @param handle Private context handle
  * @return Returns XVID_ERR_xxxx on failure, or 0 on success.
  */

 static int xvid_ff_2pass_create(xvid_plg_create_t *param, void **handle)
 {
     struct xvid_ff_pass1 *x = (struct xvid_ff_pass1 *) param->param;

     char *log = x->context->twopassbuffer;
 
     /* Do a quick bounds check */

     if (!log)

         return XVID_ERR_FAIL;
 
     /* We use snprintf() */
     /* This is because we can safely prevent a buffer overflow */
     log[0] = 0;
     snprintf(log, BUFFER_REMAINING(log),

              "# ffmpeg 2-pass log file, using xvid codec\n");

     snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),

              "# Do not modify. libxvidcore version: %d.%d.%d\n\n",
              XVID_VERSION_MAJOR(XVID_VERSION),
              XVID_VERSION_MINOR(XVID_VERSION),
              XVID_VERSION_PATCH(XVID_VERSION));

 
     *handle = x->context;
     return 0;
 }
 
 /**
  * Destroy the two-pass plugin context.
  *
  * @param ref Context pointer for the plugin

  * @param param Destroy context

  * @return Returns 0, success guaranteed
  */
 static int xvid_ff_2pass_destroy(struct xvid_context *ref,

                                  xvid_plg_destroy_t *param)
 {

     /* Currently cannot think of anything to do on destruction */
     /* Still, the framework should be here for reference/use */

     if (ref->twopassbuffer)

         ref->twopassbuffer[0] = 0;
     return 0;
 }
 
 /**
  * Enable fast encode mode during the first pass.
  *
  * @param ref Context pointer for the plugin
  * @param param Frame data
  * @return Returns 0, success guaranteed
  */
 static int xvid_ff_2pass_before(struct xvid_context *ref,

                                 xvid_plg_data_t *param)
 {

     int motion_remove;
     int motion_replacements;
     int vop_remove;
 
     /* Nothing to do here, result is changed too much */

     if (param->zone && param->zone->mode == XVID_ZONE_QUANT)

         return 0;
 
     /* We can implement a 'turbo' first pass mode here */
     param->quant = 2;
 
     /* Init values */

     motion_remove       = ~XVID_ME_CHROMA_PVOP &
                           ~XVID_ME_CHROMA_BVOP &
                           ~XVID_ME_EXTSEARCH16 &
                           ~XVID_ME_ADVANCEDDIAMOND16;

     motion_replacements = XVID_ME_FAST_MODEINTERPOLATE |

                           XVID_ME_SKIP_DELTASEARCH     |
                           XVID_ME_FASTREFINE16         |

                           XVID_ME_BFRAME_EARLYSTOP;

     vop_remove          = ~XVID_VOP_MODEDECISION_RD      &
                           ~XVID_VOP_FAST_MODEDECISION_RD &
                           ~XVID_VOP_TRELLISQUANT         &
                           ~XVID_VOP_INTER4V              &
                           ~XVID_VOP_HQACPRED;
 
     param->vol_flags    &= ~XVID_VOL_GMC;
     param->vop_flags    &= vop_remove;

     param->motion_flags &= motion_remove;
     param->motion_flags |= motion_replacements;
 
     return 0;
 }
 
 /**
  * Capture statistic data and write it during first pass.
  *
  * @param ref Context pointer for the plugin
  * @param param Statistic data
  * @return Returns XVID_ERR_xxxx on failure, or 0 on success
  */
 static int xvid_ff_2pass_after(struct xvid_context *ref,

                                xvid_plg_data_t *param)
 {

     char *log = ref->twopassbuffer;
     const char *frame_types = " ipbs";
     char frame_type;
 
     /* Quick bounds check */

     if (!log)

         return XVID_ERR_FAIL;
 
     /* Convert the type given to us into a character */

     if (param->type < 5 && param->type > 0)

         frame_type = frame_types[param->type];

     else

         return XVID_ERR_FAIL;
 
     snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),

              "%c %d %d %d %d %d %d\n",
              frame_type, param->stats.quant, param->stats.kblks,
              param->stats.mblks, param->stats.ublks,
              param->stats.length, param->stats.hlength);

 
     return 0;
 }
 
 /**
  * Dispatch function for our custom plugin.
  * This handles the dispatch for the Xvid plugin. It passes data
  * on to other functions for actual processing.
  *
  * @param ref Context pointer for the plugin
  * @param cmd The task given for us to complete
  * @param p1 First parameter (varies)
  * @param p2 Second parameter (varies)
  * @return Returns XVID_ERR_xxxx on failure, or 0 on success
  */
 static int xvid_ff_2pass(void *ref, int cmd, void *p1, void *p2)
 {

     switch (cmd) {
     case XVID_PLG_INFO:
     case XVID_PLG_FRAME:
         return 0;
     case XVID_PLG_BEFORE:
         return xvid_ff_2pass_before(ref, p1);
     case XVID_PLG_CREATE:
         return xvid_ff_2pass_create(p1, p2);
     case XVID_PLG_AFTER:
         return xvid_ff_2pass_after(ref, p1);
     case XVID_PLG_DESTROY:
         return xvid_ff_2pass_destroy(ref, p1);
     default:
         return XVID_ERR_FAIL;

     }
 }
 
 /**
  * Routine to create a global VO/VOL header for MP4 container.
  * What we do here is extract the header from the Xvid bitstream
  * as it is encoded. We also strip the repeated headers from the
  * bitstream when a global header is requested for MPEG-4 ISO
  * compliance.
  *
  * @param avctx AVCodecContext pointer to context
  * @param frame Pointer to encoded frame data
  * @param header_len Length of header to search
  * @param frame_len Length of encoded frame data
  * @return Returns new length of frame data
  */

 static int xvid_strip_vol_header(AVCodecContext *avctx, AVPacket *pkt,
                                  unsigned int header_len,
                                  unsigned int frame_len)
 {

     int vo_len = 0, i;
 

     for (i = 0; i < header_len - 3; i++) {
         if (pkt->data[i]     == 0x00 &&
             pkt->data[i + 1] == 0x00 &&
             pkt->data[i + 2] == 0x01 &&
             pkt->data[i + 3] == 0xB6) {

             vo_len = i;
             break;
         }
     }
 

     if (vo_len > 0) {

         /* We need to store the header, so extract it */

         if (!avctx->extradata) {

             avctx->extradata = av_malloc(vo_len);

             if (!avctx->extradata)
                 return AVERROR(ENOMEM);

             memcpy(avctx->extradata, pkt->data, vo_len);
             avctx->extradata_size = vo_len;
         }
         /* Less dangerous now, memmove properly copies the two

          * chunks of overlapping data */

         memmove(pkt->data, &pkt->data[vo_len], frame_len - vo_len);
         pkt->size = frame_len - vo_len;
     }
     return 0;
 }
 
 /**
  * Routine to correct a possibly erroneous framerate being fed to us.
  * Xvid currently chokes on framerates where the ticks per frame is
  * extremely large. This function works to correct problems in this area
  * by estimating a new framerate and taking the simpler fraction of
  * the two presented.
  *
  * @param avctx Context that contains the framerate to correct.
  */
 static void xvid_correct_framerate(AVCodecContext *avctx)
 {
     int frate, fbase;
     int est_frate, est_fbase;
     int gcd;
     float est_fps, fps;
 
     frate = avctx->time_base.den;
     fbase = avctx->time_base.num;
 
     gcd = av_gcd(frate, fbase);

     if (gcd > 1) {

         frate /= gcd;
         fbase /= gcd;
     }
 

     if (frate <= 65000 && fbase <= 65000) {

         avctx->time_base.den = frate;
         avctx->time_base.num = fbase;
         return;
     }
 

     fps     = (float) frate / (float) fbase;

     est_fps = roundf(fps * 1000.0) / 1000.0;
 

     est_frate = (int) est_fps;
     if (est_fps > (int) est_fps) {

         est_frate = (est_frate + 1) * 1000;

         est_fbase = (int) roundf((float) est_frate / est_fps);

     } else
         est_fbase = 1;
 
     gcd = av_gcd(est_frate, est_fbase);

     if (gcd > 1) {

         est_frate /= gcd;
         est_fbase /= gcd;
     }
 

     if (fbase > est_fbase) {

         avctx->time_base.den = est_frate;
         avctx->time_base.num = est_fbase;
         av_log(avctx, AV_LOG_DEBUG,

                "Xvid: framerate re-estimated: %.2f, %.3f%% correction\n",
                est_fps, (((est_fps - fps) / fps) * 100.0));

     } else {
         avctx->time_base.den = frate;
         avctx->time_base.num = fbase;
     }
 }

 static av_cold int xvid_encode_init(AVCodecContext *avctx)
 {

     int xerr, i, ret = -1;

     int xvid_flags = avctx->flags;

     struct xvid_context *x = avctx->priv_data;

     uint16_t *intra, *inter;
     int fd;

     xvid_plugin_single_t      single          = { 0 };
     struct xvid_ff_pass1      rc2pass1        = { 0 };
     xvid_plugin_2pass2_t      rc2pass2        = { 0 };
     xvid_plugin_lumimasking_t masking_l       = { 0 }; /* For lumi masking */
     xvid_plugin_lumimasking_t masking_v       = { 0 }; /* For variance AQ */
     xvid_plugin_ssim_t        ssim            = { 0 };
     xvid_gbl_init_t           xvid_gbl_init   = { 0 };
     xvid_enc_create_t         xvid_enc_create = { 0 };

     xvid_enc_plugin_t         plugins[4];

     x->twopassfd = -1;
 

     /* Bring in VOP flags from ffmpeg command-line */

     x->vop_flags = XVID_VOP_HALFPEL;              /* Bare minimum quality */

     if (xvid_flags & AV_CODEC_FLAG_4MV)

         x->vop_flags    |= XVID_VOP_INTER4V;      /* Level 3 */

     if (avctx->trellis)

         x->vop_flags    |= XVID_VOP_TRELLISQUANT; /* Level 5 */

     if (xvid_flags & AV_CODEC_FLAG_AC_PRED)

         x->vop_flags    |= XVID_VOP_HQACPRED;     /* Level 6 */

     if (xvid_flags & AV_CODEC_FLAG_GRAY)

         x->vop_flags    |= XVID_VOP_GREYSCALE;

     /* Decide which ME quality setting to use */
     x->me_flags = 0;

     switch (x->me_quality) {
     case 6:
     case 5:

         x->me_flags |= XVID_ME_EXTSEARCH16 |
                        XVID_ME_EXTSEARCH8;

     case 4:
     case 3:

         x->me_flags |= XVID_ME_ADVANCEDDIAMOND8 |
                        XVID_ME_HALFPELREFINE8   |
                        XVID_ME_CHROMA_PVOP      |
                        XVID_ME_CHROMA_BVOP;

     case 2:
     case 1:

         x->me_flags |= XVID_ME_ADVANCEDDIAMOND16 |
                        XVID_ME_HALFPELREFINE16;

     }

     /* Decide how we should decide blocks */

     switch (avctx->mb_decision) {
     case 2:
         x->vop_flags |=  XVID_VOP_MODEDECISION_RD;
         x->me_flags  |=  XVID_ME_HALFPELREFINE8_RD    |
                          XVID_ME_QUARTERPELREFINE8_RD |
                          XVID_ME_EXTSEARCH_RD         |
                          XVID_ME_CHECKPREDICTION_RD;
     case 1:
         if (!(x->vop_flags & XVID_VOP_MODEDECISION_RD))
             x->vop_flags |= XVID_VOP_FAST_MODEDECISION_RD;
         x->me_flags |= XVID_ME_HALFPELREFINE16_RD |
                        XVID_ME_QUARTERPELREFINE16_RD;
     default:
         break;

     }

     /* Bring in VOL flags from ffmpeg command-line */
     x->vol_flags = 0;

     if (x->gmc) {

         x->vol_flags |= XVID_VOL_GMC;

         x->me_flags  |= XVID_ME_GME_REFINE;

     }

     if (xvid_flags & AV_CODEC_FLAG_QPEL) {

         x->vol_flags |= XVID_VOL_QUARTERPEL;

         x->me_flags  |= XVID_ME_QUARTERPELREFINE16;
         if (x->vop_flags & XVID_VOP_INTER4V)

             x->me_flags |= XVID_ME_QUARTERPELREFINE8;
     }
 

     xvid_gbl_init.version   = XVID_VERSION;
     xvid_gbl_init.debug     = 0;

     xvid_gbl_init.cpu_flags = 0;

     /* Initialize */
     xvid_global(NULL, XVID_GBL_INIT, &xvid_gbl_init, NULL);
 
     /* Create the encoder reference */
     xvid_enc_create.version = XVID_VERSION;

     /* Store the desired frame size */

     xvid_enc_create.width  =
     x->xsize               = avctx->width;
     xvid_enc_create.height =
     x->ysize               = avctx->height;

     /* Xvid can determine the proper profile to use */

     /* xvid_enc_create.profile = XVID_PROFILE_S_L3; */

     /* We don't use zones */

     xvid_enc_create.zones     = NULL;

     xvid_enc_create.num_zones = 0;

 
     xvid_enc_create.num_threads = avctx->thread_count;

 #if (XVID_VERSION <= 0x010303) && (XVID_VERSION >= 0x010300)
     /* workaround for a bug in libxvidcore */
     if (avctx->height <= 16) {
         if (avctx->thread_count < 2) {
             xvid_enc_create.num_threads = 0;
         } else {
             av_log(avctx, AV_LOG_ERROR,
                    "Too small height for threads > 1.");

             return AVERROR(EINVAL);

         }
     }
 #endif

     xvid_enc_create.plugins     = plugins;

     xvid_enc_create.num_plugins = 0;

     /* Initialize Buffers */

     x->twopassbuffer     = NULL;

     x->old_twopassbuffer = NULL;

     x->twopassfile       = NULL;

     if (xvid_flags & AV_CODEC_FLAG_PASS1) {

         rc2pass1.version     = XVID_VERSION;
         rc2pass1.context     = x;
         x->twopassbuffer     = av_malloc(BUFFER_SIZE);

         x->old_twopassbuffer = av_malloc(BUFFER_SIZE);

         if (!x->twopassbuffer || !x->old_twopassbuffer) {

             av_log(avctx, AV_LOG_ERROR,

                    "Xvid: Cannot allocate 2-pass log buffers\n");

             return AVERROR(ENOMEM);

         }

         x->twopassbuffer[0]     =
         x->old_twopassbuffer[0] = 0;

         plugins[xvid_enc_create.num_plugins].func  = xvid_ff_2pass;

         plugins[xvid_enc_create.num_plugins].param = &rc2pass1;
         xvid_enc_create.num_plugins++;

     } else if (xvid_flags & AV_CODEC_FLAG_PASS2) {

         rc2pass2.version = XVID_VERSION;
         rc2pass2.bitrate = avctx->bit_rate;

         fd = avpriv_tempfile("xvidff.", &x->twopassfile, 0, avctx);

         if (fd < 0) {

             av_log(avctx, AV_LOG_ERROR, "Xvid: Cannot write 2-pass pipe\n");

             return fd;

         }

         x->twopassfd = fd;

         if (!avctx->stats_in) {

             av_log(avctx, AV_LOG_ERROR,

                    "Xvid: No 2-pass information loaded for second pass\n");

             return AVERROR(EINVAL);

         }

         ret = write(fd, avctx->stats_in, strlen(avctx->stats_in));
         if (ret == -1)
             ret = AVERROR(errno);
         else if (strlen(avctx->stats_in) > ret) {

             av_log(avctx, AV_LOG_ERROR, "Xvid: Cannot write to 2-pass pipe\n");

             ret = AVERROR(EIO);

         }

         if (ret < 0)

             return ret;

         rc2pass2.filename                          = x->twopassfile;
         plugins[xvid_enc_create.num_plugins].func  = xvid_plugin_2pass2;

         plugins[xvid_enc_create.num_plugins].param = &rc2pass2;
         xvid_enc_create.num_plugins++;

     } else if (!(xvid_flags & AV_CODEC_FLAG_QSCALE)) {

         /* Single Pass Bitrate Control! */
         single.version = XVID_VERSION;
         single.bitrate = avctx->bit_rate;

         plugins[xvid_enc_create.num_plugins].func  = xvid_plugin_single;

         plugins[xvid_enc_create.num_plugins].param = &single;
         xvid_enc_create.num_plugins++;
     }
 

     if (avctx->lumi_masking != 0.0)

         x->lumi_aq = 1;
 

     /* Luminance Masking */

     if (x->lumi_aq) {

         masking_l.method                          = 0;

         plugins[xvid_enc_create.num_plugins].func = xvid_plugin_lumimasking;

 
         /* The old behavior is that when avctx->lumi_masking is specified,
          * plugins[...].param = NULL. Trying to keep the old behavior here. */

         plugins[xvid_enc_create.num_plugins].param =
             avctx->lumi_masking ? NULL : &masking_l;
         xvid_enc_create.num_plugins++;

     }
 

     /* Variance AQ */

     if (x->variance_aq) {

         masking_v.method                           = 1;

         plugins[xvid_enc_create.num_plugins].func  = xvid_plugin_lumimasking;

         plugins[xvid_enc_create.num_plugins].param = &masking_v;

         xvid_enc_create.num_plugins++;
     }
 

     if (x->lumi_aq && x->variance_aq )

         av_log(avctx, AV_LOG_INFO,
                "Both lumi_aq and variance_aq are enabled. The resulting quality"
                "will be the worse one of the two effects made by the AQ.\n");
 

     /* SSIM */

     if (x->ssim) {

         plugins[xvid_enc_create.num_plugins].func  = xvid_plugin_ssim;
         ssim.b_printstat                           = x->ssim == 2;
         ssim.acc                                   = x->ssim_acc;
         ssim.cpu_flags                             = xvid_gbl_init.cpu_flags;
         ssim.b_visualize                           = 0;

         plugins[xvid_enc_create.num_plugins].param = &ssim;
         xvid_enc_create.num_plugins++;
     }
 

     /* Frame Rate and Key Frames */
     xvid_correct_framerate(avctx);

     xvid_enc_create.fincr = avctx->time_base.num;
     xvid_enc_create.fbase = avctx->time_base.den;

     if (avctx->gop_size > 0)

         xvid_enc_create.max_key_interval = avctx->gop_size;
     else

         xvid_enc_create.max_key_interval = 240; /* Xvid's best default */

 
     /* Quants */

     if (xvid_flags & AV_CODEC_FLAG_QSCALE)

         x->qscale = 1;
     else
         x->qscale = 0;

     xvid_enc_create.min_quant[0] = avctx->qmin;
     xvid_enc_create.min_quant[1] = avctx->qmin;
     xvid_enc_create.min_quant[2] = avctx->qmin;
     xvid_enc_create.max_quant[0] = avctx->qmax;
     xvid_enc_create.max_quant[1] = avctx->qmax;
     xvid_enc_create.max_quant[2] = avctx->qmax;

     /* Quant Matrices */

     x->intra_matrix =
     x->inter_matrix = NULL;

 
 #if FF_API_PRIVATE_OPT
 FF_DISABLE_DEPRECATION_WARNINGS

     if (avctx->mpeg_quant)

         x->mpeg_quant = avctx->mpeg_quant;
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
     if (x->mpeg_quant)

         x->vol_flags |= XVID_VOL_MPEGQUANT;
     if ((avctx->intra_matrix || avctx->inter_matrix)) {
         x->vol_flags |= XVID_VOL_MPEGQUANT;
 
         if (avctx->intra_matrix) {
             intra           = avctx->intra_matrix;
             x->intra_matrix = av_malloc(sizeof(unsigned char) * 64);

             if (!x->intra_matrix)
                 return AVERROR(ENOMEM);

         } else
             intra = NULL;
         if (avctx->inter_matrix) {
             inter           = avctx->inter_matrix;
             x->inter_matrix = av_malloc(sizeof(unsigned char) * 64);

             if (!x->inter_matrix)
                 return AVERROR(ENOMEM);

         } else
             inter = NULL;
 
         for (i = 0; i < 64; i++) {
             if (intra)
                 x->intra_matrix[i] = (unsigned char) intra[i];
             if (inter)
                 x->inter_matrix[i] = (unsigned char) inter[i];
         }

     }

     /* Misc Settings */
     xvid_enc_create.frame_drop_ratio = 0;

     xvid_enc_create.global           = 0;

     if (xvid_flags & AV_CODEC_FLAG_CLOSED_GOP)

         xvid_enc_create.global |= XVID_GLOBAL_CLOSED_GOP;
 
     /* Determines which codec mode we are operating in */

     avctx->extradata      = NULL;

     avctx->extradata_size = 0;

     if (xvid_flags & AV_CODEC_FLAG_GLOBAL_HEADER) {

         /* In this case, we are claiming to be MPEG-4 */

         x->quicktime_format = 1;

         avctx->codec_id     = AV_CODEC_ID_MPEG4;

     } else {

         /* We are claiming to be Xvid */

         x->quicktime_format = 0;

         if (!avctx->codec_tag)

             avctx->codec_tag = AV_RL32("xvid");

     }
 

     /* Bframes */

     xvid_enc_create.max_bframes   = avctx->max_b_frames;

     xvid_enc_create.bquant_offset = 100 * avctx->b_quant_offset;

     xvid_enc_create.bquant_ratio  = 100 * avctx->b_quant_factor;
     if (avctx->max_b_frames > 0 && !x->quicktime_format)
         xvid_enc_create.global |= XVID_GLOBAL_PACKED;

     av_assert0(xvid_enc_create.num_plugins + (!!x->ssim) + (!!x->variance_aq) + (!!x->lumi_aq) <= FF_ARRAY_ELEMS(plugins));
 

     /* Encode a dummy frame to get the extradata immediately */
     if (x->quicktime_format) {
         AVFrame *picture;

         AVPacket packet = {0};

         int size, got_packet, ret;
 
         av_init_packet(&packet);
 
         picture = av_frame_alloc();
         if (!picture)
             return AVERROR(ENOMEM);
 
         xerr = xvid_encore(NULL, XVID_ENC_CREATE, &xvid_enc_create, NULL);
         if( xerr ) {
             av_frame_free(&picture);
             av_log(avctx, AV_LOG_ERROR, "Xvid: Could not create encoder reference\n");
             return AVERROR_EXTERNAL;
         }
         x->encoder_handle = xvid_enc_create.handle;
         size = ((avctx->width + 1) & ~1) * ((avctx->height + 1) & ~1);
         picture->data[0] = av_malloc(size + size / 2);
         if (!picture->data[0]) {
             av_frame_free(&picture);
             return AVERROR(ENOMEM);
         }
         picture->data[1] = picture->data[0] + size;
         picture->data[2] = picture->data[1] + size / 4;
         memset(picture->data[0], 0, size);
         memset(picture->data[1], 128, size / 2);
         ret = xvid_encode_frame(avctx, &packet, picture, &got_packet);
         if (!ret && got_packet)
             av_packet_unref(&packet);
         av_free(picture->data[0]);
         av_frame_free(&picture);
         xvid_encore(x->encoder_handle, XVID_ENC_DESTROY, NULL, NULL);
     }
 

     /* Create encoder context */
     xerr = xvid_encore(NULL, XVID_ENC_CREATE, &xvid_enc_create, NULL);

     if (xerr) {

         av_log(avctx, AV_LOG_ERROR, "Xvid: Could not create encoder reference\n");

         return AVERROR_EXTERNAL;

     }

     x->encoder_handle  = xvid_enc_create.handle;

 
     return 0;
 }
 

 static int xvid_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                              const AVFrame *picture, int *got_packet)
 {
     int xerr, i, ret, user_packet = !!pkt->data;

     struct xvid_context *x = avctx->priv_data;

     int mb_width  = (avctx->width  + 15) / 16;
     int mb_height = (avctx->height + 15) / 16;
     char *tmp;

     xvid_enc_frame_t xvid_enc_frame = { 0 };
     xvid_enc_stats_t xvid_enc_stats = { 0 };

     if ((ret = ff_alloc_packet2(avctx, pkt, mb_width*(int64_t)mb_height*MAX_MB_BYTES + AV_INPUT_BUFFER_MIN_SIZE, 0)) < 0)

         return ret;
 

     /* Start setting up the frame */
     xvid_enc_frame.version = XVID_VERSION;
     xvid_enc_stats.version = XVID_VERSION;
 

     /* Let Xvid know where to put the frame. */

     xvid_enc_frame.bitstream = pkt->data;
     xvid_enc_frame.length    = pkt->size;

     /* Initialize input image fields */

     if (avctx->pix_fmt != AV_PIX_FMT_YUV420P) {
         av_log(avctx, AV_LOG_ERROR,
                "Xvid: Color spaces other than 420P not supported\n");

         return AVERROR(EINVAL);

     }

     xvid_enc_frame.input.csp = XVID_CSP_PLANAR; /* YUV420P */
 

     for (i = 0; i < 4; i++) {
         xvid_enc_frame.input.plane[i]  = picture->data[i];

         xvid_enc_frame.input.stride[i] = picture->linesize[i];
     }
 
     /* Encoder Flags */
     xvid_enc_frame.vop_flags = x->vop_flags;
     xvid_enc_frame.vol_flags = x->vol_flags;

     xvid_enc_frame.motion    = x->me_flags;
     xvid_enc_frame.type      =

         picture->pict_type == AV_PICTURE_TYPE_I ? XVID_TYPE_IVOP :
         picture->pict_type == AV_PICTURE_TYPE_P ? XVID_TYPE_PVOP :
         picture->pict_type == AV_PICTURE_TYPE_B ? XVID_TYPE_BVOP :

                                                   XVID_TYPE_AUTO;

     /* Pixel aspect ratio setting */

     if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.num > 255 ||
         avctx->sample_aspect_ratio.den < 0 || avctx->sample_aspect_ratio.den > 255) {

         av_log(avctx, AV_LOG_WARNING,
                "Invalid pixel aspect ratio %i/%i, limit is 255/255 reducing\n",

                avctx->sample_aspect_ratio.num, avctx->sample_aspect_ratio.den);

         av_reduce(&avctx->sample_aspect_ratio.num, &avctx->sample_aspect_ratio.den,
                    avctx->sample_aspect_ratio.num,  avctx->sample_aspect_ratio.den, 255);

     }

     xvid_enc_frame.par        = XVID_PAR_EXT;

     xvid_enc_frame.par_width  = avctx->sample_aspect_ratio.num;
     xvid_enc_frame.par_height = avctx->sample_aspect_ratio.den;
 

     /* Quant Setting */

     if (x->qscale)
         xvid_enc_frame.quant = picture->quality / FF_QP2LAMBDA;
     else
         xvid_enc_frame.quant = 0;

     /* Matrices */
     xvid_enc_frame.quant_intra_matrix = x->intra_matrix;
     xvid_enc_frame.quant_inter_matrix = x->inter_matrix;
 
     /* Encode */

     xerr = xvid_encore(x->encoder_handle, XVID_ENC_ENCODE,

                        &xvid_enc_frame, &xvid_enc_stats);

 
     /* Two-pass log buffer swapping */
     avctx->stats_out = NULL;

     if (x->twopassbuffer) {
         tmp                  = x->old_twopassbuffer;

         x->old_twopassbuffer = x->twopassbuffer;

         x->twopassbuffer     = tmp;
         x->twopassbuffer[0]  = 0;
         if (x->old_twopassbuffer[0] != 0) {

             avctx->stats_out = x->old_twopassbuffer;
         }

     }
 

     if (xerr > 0) {

         int pict_type;

         *got_packet = 1;
 

         if (xvid_enc_stats.type == XVID_TYPE_PVOP)

             pict_type = AV_PICTURE_TYPE_P;

         else if (xvid_enc_stats.type == XVID_TYPE_BVOP)

             pict_type = AV_PICTURE_TYPE_B;

         else if (xvid_enc_stats.type == XVID_TYPE_SVOP)

             pict_type = AV_PICTURE_TYPE_S;

         else

             pict_type = AV_PICTURE_TYPE_I;
 
 #if FF_API_CODED_FRAME
 FF_DISABLE_DEPRECATION_WARNINGS
         avctx->coded_frame->pict_type = pict_type;
         avctx->coded_frame->quality = xvid_enc_stats.quant * FF_QP2LAMBDA;

 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

 
         ff_side_data_set_encoder_stats(pkt, xvid_enc_stats.quant * FF_QP2LAMBDA, NULL, 0, pict_type);
 

         if (xvid_enc_frame.out_flags & XVID_KEYFRAME) {

 #if FF_API_CODED_FRAME
 FF_DISABLE_DEPRECATION_WARNINGS

             avctx->coded_frame->key_frame = 1;

 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

             pkt->flags  |= AV_PKT_FLAG_KEY;
             if (x->quicktime_format)

                 return xvid_strip_vol_header(avctx, pkt,

                                              xvid_enc_stats.hlength, xerr);

         } else {

 #if FF_API_CODED_FRAME
 FF_DISABLE_DEPRECATION_WARNINGS

             avctx->coded_frame->key_frame = 0;

 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

         }

         pkt->size = xerr;
 
         return 0;

     } else {

         if (!user_packet)

             av_packet_unref(pkt);

         if (!xerr)
             return 0;

         av_log(avctx, AV_LOG_ERROR,
                "Xvid: Encoding Error Occurred: %i\n", xerr);

         return AVERROR_EXTERNAL;

     }
 }
 

 static av_cold int xvid_encode_close(AVCodecContext *avctx)
 {

     struct xvid_context *x = avctx->priv_data;

     if (x->encoder_handle) {

         xvid_encore(x->encoder_handle, XVID_ENC_DESTROY, NULL, NULL);

         x->encoder_handle = NULL;
     }

     av_freep(&avctx->extradata);

     if (x->twopassbuffer) {

         av_freep(&x->twopassbuffer);
         av_freep(&x->old_twopassbuffer);

         avctx->stats_out = NULL;

     }

     if (x->twopassfd>=0) {
         unlink(x->twopassfile);
         close(x->twopassfd);
         x->twopassfd = -1;
     }

     av_freep(&x->twopassfile);
     av_freep(&x->intra_matrix);
     av_freep(&x->inter_matrix);

 
     return 0;
 }
 

 #define OFFSET(x) offsetof(struct xvid_context, x)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {

     { "lumi_aq",     "Luminance masking AQ",            OFFSET(lumi_aq),     AV_OPT_TYPE_INT,   { .i64 = 0 },       0,       1, VE         },
     { "variance_aq", "Variance AQ",                     OFFSET(variance_aq), AV_OPT_TYPE_INT,   { .i64 = 0 },       0,       1, VE         },
     { "ssim",        "Show SSIM information to stdout", OFFSET(ssim),        AV_OPT_TYPE_INT,   { .i64 = 0 },       0,       2, VE, "ssim" },
     { "off",         NULL,                                                0, AV_OPT_TYPE_CONST, { .i64 = 0 }, INT_MIN, INT_MAX, VE, "ssim" },
     { "avg",         NULL,                                                0, AV_OPT_TYPE_CONST, { .i64 = 1 }, INT_MIN, INT_MAX, VE, "ssim" },
     { "frame",       NULL,                                                0, AV_OPT_TYPE_CONST, { .i64 = 2 }, INT_MIN, INT_MAX, VE, "ssim" },
     { "ssim_acc",    "SSIM accuracy",                   OFFSET(ssim_acc),    AV_OPT_TYPE_INT,   { .i64 = 2 },       0,       4, VE         },
     { "gmc",         "use GMC",                         OFFSET(gmc),         AV_OPT_TYPE_INT,   { .i64 = 0 },       0,       1, VE         },

     { "me_quality",  "Motion estimation quality",       OFFSET(me_quality),  AV_OPT_TYPE_INT,   { .i64 = 4 },       0,       6, VE         },

     { "mpeg_quant",  "Use MPEG quantizers instead of H.263", OFFSET(mpeg_quant), AV_OPT_TYPE_INT, { .i64 = 0 },     0,       1, VE         },

     { NULL },
 };
 
 static const AVClass xvid_class = {
     .class_name = "libxvid",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 AVCodec ff_libxvid_encoder = {

     .name           = "libxvid",

     .long_name      = NULL_IF_CONFIG_SMALL("libxvidcore MPEG-4 part 2"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_MPEG4,

     .priv_data_size = sizeof(struct xvid_context),
     .init           = xvid_encode_init,

     .encode2        = xvid_encode_frame,

     .close          = xvid_encode_close,

     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },

     .priv_class     = &xvid_class,

     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
                       FF_CODEC_CAP_INIT_CLEANUP,

     .wrapper_name   = "libxvid",

 };