/*
  * Interface to xvidcore for mpeg4 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 <xvid.h>
 #include <unistd.h>
 #include "avcodec.h"

 #include "internal.h"

 #include "libavutil/file.h"

 #include "libavutil/cpu.h"

 #include "libavutil/intreadwrite.h"

 #include "libavutil/mathematics.h"

 #include "libxvid.h"

 #include "mpegvideo.h"

 
 /**
  * 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 {

     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. */

 };

 /**
  * 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);
 

 /*
  * 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 == NULL )
         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 Destrooy 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 != NULL )
         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 == NULL )
         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 == NULL ) {
             avctx->extradata = av_malloc(vo_len);
             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;
     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 & 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 & CODEC_FLAG_AC_PRED )

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

     if( xvid_flags & CODEC_FLAG_GRAY )

         x->vop_flags    |= XVID_VOP_GREYSCALE;

     /* Decide which ME quality setting to use */
     x->me_flags = 0;
     switch( avctx->me_method ) {
        case ME_FULL:   /* Quality 6 */

            x->me_flags  |=  XVID_ME_EXTSEARCH16
                         |   XVID_ME_EXTSEARCH8;

        case ME_EPZS:   /* Quality 4 */

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

        case ME_LOG:    /* Quality 2 */
        case ME_PHODS:
        case ME_X1:

            x->me_flags  |=  XVID_ME_ADVANCEDDIAMOND16
                         |   XVID_ME_HALFPELREFINE16;

        case ME_ZERO:   /* Quality 0 */
        default:
            break;
     }

     /* 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( xvid_flags & CODEC_FLAG_GMC ) {

         x->vol_flags    |= XVID_VOL_GMC;
         x->me_flags     |= XVID_ME_GME_REFINE;

     }

     if( xvid_flags & 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;

 #if ARCH_PPC

     /* Xvid's PPC support is borked, use libavcodec to detect */

 #if HAVE_ALTIVEC

     if (av_get_cpu_flags() & AV_CPU_FLAG_ALTIVEC) {

         xvid_gbl_init.cpu_flags = XVID_CPU_FORCE | XVID_CPU_ALTIVEC;
     } else
 #endif

         xvid_gbl_init.cpu_flags = XVID_CPU_FORCE;

 #else

     /* Xvid can detect on x86 */

     xvid_gbl_init.cpu_flags = 0;
 #endif

     /* 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;

     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 & 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 == NULL || x->old_twopassbuffer == NULL ) {
             av_log(avctx, AV_LOG_ERROR,

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

             goto fail;

         }
         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 & CODEC_FLAG_PASS2 ) {
         rc2pass2.version = XVID_VERSION;
         rc2pass2.bitrate = avctx->bit_rate;

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

         if( fd == -1 ) {
             av_log(avctx, AV_LOG_ERROR,

                 "Xvid: Cannot write 2-pass pipe\n");

             goto fail;

         }

         x->twopassfd = fd;

         if( avctx->stats_in == NULL ) {
             av_log(avctx, AV_LOG_ERROR,

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

             goto fail;

         }

 
         if( strlen(avctx->stats_in) >

               write(fd, avctx->stats_in, strlen(avctx->stats_in)) ) {
             av_log(avctx, AV_LOG_ERROR,

                 "Xvid: Cannot write to 2-pass pipe\n");

             goto fail;

         }

         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 & 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 & 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( avctx->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);

        } else

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

        } 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 & 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 & CODEC_FLAG_GLOBAL_HEADER ) {
         /* In this case, we are claiming to be MPEG4 */
         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));
 

     /* 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");

         goto fail;

     }

     x->encoder_handle = xvid_enc_create.handle;

     avctx->coded_frame = av_frame_alloc();
     if (!avctx->coded_frame)
         return AVERROR(ENOMEM);

 
     return 0;

 fail:
     xvid_encode_close(avctx);
     return -1;

 }
 

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

     char *tmp;

     struct xvid_context *x = avctx->priv_data;

     AVFrame *p = avctx->coded_frame;

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

     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*mb_height*MAX_MB_BYTES + FF_MIN_BUFFER_SIZE)) < 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 -1;
     }

     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) {
         *got_packet = 1;
 

         p->quality = xvid_enc_stats.quant * FF_QP2LAMBDA;
         if( xvid_enc_stats.type == XVID_TYPE_PVOP )

             p->pict_type = AV_PICTURE_TYPE_P;

         else if( xvid_enc_stats.type == XVID_TYPE_BVOP )

             p->pict_type = AV_PICTURE_TYPE_B;

         else if( xvid_enc_stats.type == XVID_TYPE_SVOP )

             p->pict_type = AV_PICTURE_TYPE_S;

         else

             p->pict_type = AV_PICTURE_TYPE_I;

         if( xvid_enc_frame.out_flags & XVID_KEYFRAME ) {
             p->key_frame = 1;

             pkt->flags |= AV_PKT_FLAG_KEY;

             if( x->quicktime_format )

                 return xvid_strip_vol_header(avctx, pkt,

                     xvid_enc_stats.hlength, xerr);

          } else

             p->key_frame = 0;
 

         pkt->size = xerr;
 
         return 0;

     } else {

         if (!user_packet)
             av_free_packet(pkt);
         if (!xerr)
             return 0;

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

         return -1;
     }
 }
 

 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 != NULL ) {

         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 },

     { 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,

 };