text: /*
   * 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 {
      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. */
  };
  
  /**
   * 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,
  };
  