path: root/libmpdemux/video.c

/*
 * video frame reading
 *
 * This file is part of MPlayer.
 *
 * MPlayer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * MPlayer 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include <stdio.h>
#if HAVE_MALLOC_H
#include <malloc.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mp_msg.h"
#include "help_mp.h"

#include "stream/stream.h"
#include "demuxer.h"
#include "stheader.h"
#include "parse_es.h"
#include "mpeg_hdr.h"

/* sub_cc (closed captions)*/
#include "sub_cc.h"

/* biCompression constant */
#define BI_RGB        0L

#ifdef CONFIG_LIVE555
#include "demux_rtp.h"
#endif

static mp_mpeg_header_t picture;

static int telecine=0;
static float telecine_cnt=-2.5;

typedef enum {
  VIDEO_MPEG12,
  VIDEO_MPEG4,
  VIDEO_H264,
  VIDEO_VC1,
  VIDEO_OTHER
} video_codec_t;

static video_codec_t find_video_codec(sh_video_t *sh_video)
{
  demux_stream_t *d_video=sh_video->ds;
  int fmt = d_video->demuxer->file_format;

  if(
    (fmt == DEMUXER_TYPE_PVA) ||
    (fmt == DEMUXER_TYPE_MPEG_ES) ||
    (fmt == DEMUXER_TYPE_MPEG_GXF) ||
    (fmt == DEMUXER_TYPE_MPEG_PES) ||
    (
      (fmt == DEMUXER_TYPE_MPEG_PS || fmt == DEMUXER_TYPE_MPEG_TS) &&
      ((! sh_video->format) || (sh_video->format==0x10000001) || (sh_video->format==0x10000002))
    ) ||
    (fmt == DEMUXER_TYPE_MPEG_TY)
#ifdef CONFIG_LIVE555
    || ((fmt == DEMUXER_TYPE_RTP) && demux_is_mpeg_rtp_stream(d_video->demuxer))
#endif
  )
    return VIDEO_MPEG12;
  else if((fmt == DEMUXER_TYPE_MPEG4_ES) ||
    ((fmt == DEMUXER_TYPE_MPEG_TS) && (sh_video->format==0x10000004)) ||
    ((fmt == DEMUXER_TYPE_MPEG_PS) && (sh_video->format==0x10000004))
  )
    return VIDEO_MPEG4;
  else if((fmt == DEMUXER_TYPE_H264_ES) ||
    ((fmt == DEMUXER_TYPE_MPEG_TS) && (sh_video->format==0x10000005)) ||
    ((fmt == DEMUXER_TYPE_MPEG_PS) && (sh_video->format==0x10000005))
  )
    return VIDEO_H264;
  else if((fmt == DEMUXER_TYPE_MPEG_PS ||  fmt == DEMUXER_TYPE_MPEG_TS) &&
    (sh_video->format==mmioFOURCC('W', 'V', 'C', '1')))
    return VIDEO_VC1;
  else if (fmt == DEMUXER_TYPE_ASF && sh_video->bih && sh_video->bih->biCompression == mmioFOURCC('D', 'V', 'R', ' '))
    return VIDEO_MPEG12;
  else
    return VIDEO_OTHER;
}

int video_read_properties(sh_video_t *sh_video){
demux_stream_t *d_video=sh_video->ds;
video_codec_t video_codec = find_video_codec(sh_video);
// Determine image properties:
switch(video_codec){
 case VIDEO_OTHER: {
 if((d_video->demuxer->file_format == DEMUXER_TYPE_ASF) || (d_video->demuxer->file_format == DEMUXER_TYPE_AVI)) {
    // display info:
    // in case no strf chunk has been seen in avi, we have no bitmap header
    if(!sh_video->bih) return 0;
    sh_video->format=sh_video->bih->biCompression;
    sh_video->disp_w=sh_video->bih->biWidth;
    sh_video->disp_h=abs(sh_video->bih->biHeight);
  }
  break;
 }
 case VIDEO_MPEG4: {
   int pos = 0, vop_cnt=0, units[3];
   videobuf_len=0; videobuf_code_len=0;
   mp_msg(MSGT_DECVIDEO,MSGL_V,"Searching for Video Object Start code... ");
   while(1){
      int i=sync_video_packet(d_video);
      if(i<=0x11F) break; // found it!
      if(!i || !skip_video_packet(d_video)){
        mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        return 0;
      }
   }
   mp_msg(MSGT_DECVIDEO,MSGL_V,"OK!\n");
   if(!videobuffer) {
     videobuffer=(char*)memalign(8,VIDEOBUFFER_SIZE + MP_INPUT_BUFFER_PADDING_SIZE);
     if (videobuffer) memset(videobuffer+VIDEOBUFFER_SIZE, 0, MP_INPUT_BUFFER_PADDING_SIZE);
     else {
       mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_ShMemAllocFail);
       return 0;
     }
   }
   mp_msg(MSGT_DECVIDEO,MSGL_V,"Searching for Video Object Layer Start code... ");
   while(1){
      int i=sync_video_packet(d_video);
      mp_msg(MSGT_DECVIDEO,MSGL_V,"M4V: 0x%X\n",i);
      if(i>=0x120 && i<=0x12F) break; // found it!
      if(!i || !read_video_packet(d_video)){
        mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        return 0;
      }
   }
   pos = videobuf_len+4;
   if(!read_video_packet(d_video)){
     mp_msg(MSGT_DECVIDEO,MSGL_ERR,"Can't read Video Object Layer Header\n");
     return 0;
   }
   mp4_header_process_vol(&picture, &(videobuffer[pos]));
   mp_msg(MSGT_DECVIDEO,MSGL_V,"OK! FPS SEEMS TO BE %.3f\nSearching for Video Object Plane Start code... ", sh_video->fps);
 mp4_init:
   while(1){
      int i=sync_video_packet(d_video);
      if(i==0x1B6) break; // found it!
      if(!i || !read_video_packet(d_video)){
        mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        return 0;
      }
   }
   pos = videobuf_len+4;
   if(!read_video_packet(d_video)){
     mp_msg(MSGT_DECVIDEO,MSGL_ERR,"Can't read Video Object Plane Header\n");
     return 0;
   }
   mp4_header_process_vop(&picture, &(videobuffer[pos]));
   units[vop_cnt] = picture.timeinc_unit;
   vop_cnt++;
   //mp_msg(MSGT_DECVIDEO,MSGL_V, "TYPE: %d, unit: %d\n", picture.picture_type, picture.timeinc_unit);
   if(!picture.fps) {
     int i, mn, md, mx, diff;
     if(vop_cnt < 3)
          goto mp4_init;

     i=0;
     mn = mx = units[0];
     for(i=0; i<3; i++) {
       if(units[i] < mn)
         mn = units[i];
       if(units[i] > mx)
         mx = units[i];
     }
     md = mn;
     for(i=0; i<3; i++) {
       if((units[i] > mn) && (units[i] < mx))
         md = units[i];
     }
     mp_msg(MSGT_DECVIDEO,MSGL_V, "MIN: %d, mid: %d, max: %d\n", mn, md, mx);
     if(mx - md > md - mn)
       diff = md - mn;
     else
       diff = mx - md;
     if(diff > 0){
       picture.fps = ((float)picture.timeinc_resolution) / diff;
       mp_msg(MSGT_DECVIDEO,MSGL_V, "FPS seems to be: %f, resolution: %d, delta_units: %d\n", picture.fps, picture.timeinc_resolution, diff);
     }
   }
   if(picture.fps) {
    sh_video->fps=picture.fps;
    sh_video->frametime=1.0/picture.fps;
    mp_msg(MSGT_DECVIDEO,MSGL_INFO, "FPS seems to be: %f\n", picture.fps);
   }
   mp_msg(MSGT_DECVIDEO,MSGL_V,"OK!\n");
   sh_video->format=0x10000004;
   break;
 }
 case VIDEO_H264: {
   int pos = 0;
   videobuf_len=0; videobuf_code_len=0;
   mp_msg(MSGT_DECVIDEO,MSGL_V,"Searching for sequence parameter set... ");
   while(1){
      int i=sync_video_packet(d_video);
      if((i&~0x60) == 0x107 && i != 0x107) break; // found it!
      if(!i || !skip_video_packet(d_video)){
        mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        return 0;
      }
   }
   mp_msg(MSGT_DECVIDEO,MSGL_V,"OK!\n");
   if(!videobuffer) {
     videobuffer=(char*)memalign(8,VIDEOBUFFER_SIZE + MP_INPUT_BUFFER_PADDING_SIZE);
     if (videobuffer) memset(videobuffer+VIDEOBUFFER_SIZE, 0, MP_INPUT_BUFFER_PADDING_SIZE);
     else {
       mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_ShMemAllocFail);
       return 0;
     }
   }
   pos = videobuf_len+4;
   if(!read_video_packet(d_video)){
     mp_msg(MSGT_DECVIDEO,MSGL_ERR,"Can't read sequence parameter set\n");
     return 0;
   }
   h264_parse_sps(&picture, &(videobuffer[pos]), videobuf_len - pos);
   mp_msg(MSGT_DECVIDEO,MSGL_V,"Searching for picture parameter set... ");
   while(1){
      int i=sync_video_packet(d_video);
      mp_msg(MSGT_DECVIDEO,MSGL_V,"H264: 0x%X\n",i);
      if((i&~0x60) == 0x108 && i != 0x108) break; // found it!
      if(!i || !read_video_packet(d_video)){
        mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        return 0;
      }
   }
   mp_msg(MSGT_DECVIDEO,MSGL_V,"OK!\nSearching for Slice... ");
   while(1){
      int i=sync_video_packet(d_video);
      if((i&~0x60) == 0x101 || (i&~0x60) == 0x102 || (i&~0x60) == 0x105) break; // found it!
      if(!i || !read_video_packet(d_video)){
        mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        return 0;
      }
   }
   mp_msg(MSGT_DECVIDEO,MSGL_V,"OK!\n");
   sh_video->format=0x10000005;
   if(picture.fps) {
     sh_video->fps=picture.fps;
     sh_video->frametime=1.0/picture.fps;
     mp_msg(MSGT_DECVIDEO,MSGL_INFO, "FPS seems to be: %f\n", picture.fps);
   }
   break;
 }
 case VIDEO_MPEG12: {
   if (d_video->demuxer->file_format == DEMUXER_TYPE_ASF) { // DVR-MS
     if(!sh_video->bih) return 0;
     sh_video->format=sh_video->bih->biCompression;
   }
mpeg_header_parser:
   // Find sequence_header first:
   videobuf_len=0; videobuf_code_len=0;
   telecine=0; telecine_cnt=-2.5;
   mp_msg(MSGT_DECVIDEO,MSGL_V,"Searching for sequence header... ");
   while(1){
      int i=sync_video_packet(d_video);
      if(i==0x1B3) break; // found it!
      if(!i || !skip_video_packet(d_video)){
        if( mp_msg_test(MSGT_DECVIDEO,MSGL_V) )  mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_MpegNoSequHdr);
        return 0;
      }
   }
   mp_msg(MSGT_DECVIDEO,MSGL_V,"OK!\n");
   // ========= Read & process sequence header & extension ============
   if(!videobuffer) {
     videobuffer=(char*)memalign(8,VIDEOBUFFER_SIZE + MP_INPUT_BUFFER_PADDING_SIZE);
     if (videobuffer) memset(videobuffer+VIDEOBUFFER_SIZE, 0, MP_INPUT_BUFFER_PADDING_SIZE);
     else {
       mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_ShMemAllocFail);
       return 0;
     }
   }

   if(!read_video_packet(d_video)){
     mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_CannotReadMpegSequHdr);
     return 0;
   }
   if(mp_header_process_sequence_header (&picture, &videobuffer[4])) {
     mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_BadMpegSequHdr);
     goto mpeg_header_parser;
   }
   if(sync_video_packet(d_video)==0x1B5){ // next packet is seq. ext.
    int pos=videobuf_len;
    if(!read_video_packet(d_video)){
      mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_CannotReadMpegSequHdrEx);
      return 0;
    }
    if(mp_header_process_extension (&picture, &videobuffer[pos+4])) {
      mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_BadMpegSequHdrEx);
      return 0;
    }
   }

   // display info:
   sh_video->format=picture.mpeg1?0x10000001:0x10000002; // mpeg video
   sh_video->fps=picture.fps;
   if(!sh_video->fps){
     sh_video->frametime=0;
   } else {
     sh_video->frametime=1.0/picture.fps;
   }
   sh_video->disp_w=picture.display_picture_width;
   sh_video->disp_h=picture.display_picture_height;
   // bitrate:
   if(picture.bitrate!=0x3FFFF) // unspecified/VBR ?
       sh_video->i_bps=picture.bitrate * 400 / 8;
   // info:
   mp_dbg(MSGT_DECVIDEO,MSGL_DBG2,"mpeg bitrate: %d (%X)\n",picture.bitrate,picture.bitrate);
   mp_msg(MSGT_DECVIDEO,MSGL_INFO,"VIDEO:  %s  %dx%d  (aspect %d)  %5.3f fps  %5.1f kbps (%4.1f kbyte/s)\n",
    picture.mpeg1?"MPEG1":"MPEG2",
    sh_video->disp_w,sh_video->disp_h,
    picture.aspect_ratio_information,
    sh_video->fps,
    sh_video->i_bps * 8 / 1000.0,
    sh_video->i_bps / 1000.0 );
  break;
 }
 case VIDEO_VC1: {
   // Find sequence_header:
   videobuf_len=0;
   videobuf_code_len=0;
   mp_msg(MSGT_DECVIDEO,MSGL_INFO,"Searching for VC1 sequence header... ");
   while(1){
      int i=sync_video_packet(d_video);
      if(i==0x10F) break; // found it!
      if(!i || !skip_video_packet(d_video)){
        if( mp_msg_test(MSGT_DECVIDEO,MSGL_V) )  mp_msg(MSGT_DECVIDEO,MSGL_V,"NONE :(\n");
        mp_msg(MSGT_DECVIDEO,MSGL_ERR, "Couldn't find VC-1 sequence header\n");
        return 0;
      }
   }
   mp_msg(MSGT_DECVIDEO,MSGL_INFO,"found\n");
   if(!videobuffer) {
     videobuffer=(char*)memalign(8,VIDEOBUFFER_SIZE + MP_INPUT_BUFFER_PADDING_SIZE);
     if (videobuffer) memset(videobuffer+VIDEOBUFFER_SIZE, 0, MP_INPUT_BUFFER_PADDING_SIZE);
     else {
       mp_msg(MSGT_DECVIDEO,MSGL_ERR,MSGTR_ShMemAllocFail);
       return 0;
     }
   }
   if(!read_video_packet(d_video)){
     mp_msg(MSGT_DECVIDEO,MSGL_ERR, "Couldn't read VC-1 sequence header!\n");
     return 0;
   }

   while(1) {
      int i=sync_video_packet(d_video);
      if(i==0x10E) break; // found it!
      if(!i || !skip_video_packet(d_video)){
        mp_msg(MSGT_DECVIDEO,MSGL_V,"Couldn't find VC-1 entry point sync-code:(\n");
        return 0;
      }
   }
   if(!read_video_packet(d_video)){
      mp_msg(MSGT_DECVIDEO,MSGL_V,"Couldn't read VC-1 entry point sync-code:(\n");
      return 0;
   }

   if(mp_vc1_decode_sequence_header(&picture, &videobuffer[4], videobuf_len-4)) {
     sh_video->bih = (BITMAPINFOHEADER *) calloc(1, sizeof(BITMAPINFOHEADER) + videobuf_len);
     if(sh_video->bih == NULL) {
       mp_msg(MSGT_DECVIDEO,MSGL_ERR,"Couldn't alloc %d bytes for VC-1 extradata!\n", sizeof(BITMAPINFOHEADER) + videobuf_len);
       return 0;
     }
     sh_video->bih->biSize= sizeof(BITMAPINFOHEADER) + videobuf_len;
     memcpy(sh_video->bih + 1, videobuffer, videobuf_len);
     sh_video->bih->biCompression = sh_video->format;
     sh_video->bih->biWidth = sh_video->disp_w = picture.display_picture_width;
     sh_video->bih->biHeight = sh_video->disp_h = picture.display_picture_height;
     if(picture.fps > 0) {
       sh_video->frametime=1.0/picture.fps;
       sh_video->fps = picture.fps;
     }
     mp_msg(MSGT_DECVIDEO,MSGL_INFO,"VIDEO:  VC-1  %dx%d, %5.3f fps, header len: %d\n",
       sh_video->disp_w, sh_video->disp_h, sh_video->fps, videobuf_len);
   }
  break;
 }
} // switch(file_format)

return 1;
}

void ty_processuserdata( unsigned char* buf, int len );

static void process_userdata(unsigned char* buf,int len){
    int i;
    /* if the user data starts with "CC", assume it is a CC info packet */
    if(len>2 && buf[0]=='C' && buf[1]=='C'){
//    mp_msg(MSGT_DECVIDEO,MSGL_DBG2,"video.c: process_userdata() detected Closed Captions!\n");
      subcc_process_data(buf+2,len-2);
    }
    if( len > 2 && buf[ 0 ] == 'T' && buf[ 1 ] == 'Y' )
    {
       ty_processuserdata( buf + 2, len - 2 );
       return;
    }
    if(verbose<2) return;
    fprintf(stderr, "user_data: len=%3d  %02X %02X %02X %02X '",
      len, buf[0], buf[1], buf[2], buf[3]);
    for(i=0;i<len;i++)
//    if(buf[i]>=32 && buf[i]<127) fputc(buf[i], stderr);
      if(buf[i]&0x60) fputc(buf[i]&0x7F, stderr);
    fprintf(stderr, "'\n");
}

int video_read_frame(sh_video_t* sh_video,float* frame_time_ptr,unsigned char** start,int force_fps){
    demux_stream_t *d_video=sh_video->ds;
    demuxer_t *demuxer=d_video->demuxer;
    float frame_time=1;
    float pts1=d_video->pts;
    float pts=0;
    int picture_coding_type=0;
    int in_size=0;
    video_codec_t video_codec = find_video_codec(sh_video);

    *start=NULL;

  if(video_codec == VIDEO_MPEG12){
        int in_frame=0;
        //float newfps;
        //videobuf_len=0;
        while(videobuf_len<VIDEOBUFFER_SIZE-MAX_VIDEO_PACKET_SIZE){
          int i=sync_video_packet(d_video);
          //void* buffer=&videobuffer[videobuf_len+4];
          int start=videobuf_len+4;
          if(in_frame){
            if(i<0x101 || i>=0x1B0){  // not slice code -> end of frame
              if(!i) return -1; // EOF
              break;
            }
          } else {
            if(i==0x100){
              pts=d_video->pts;
              d_video->pts=0;
            }
            if(i>=0x101 && i<0x1B0) in_frame=1; // picture startcode
            else if(!i) return -1; // EOF
          }
          if(!read_video_packet(d_video)) return -1; // EOF
          // process headers:
          switch(i){
            case 0x1B3: mp_header_process_sequence_header (&picture, &videobuffer[start]);break;
            case 0x1B5: mp_header_process_extension (&picture, &videobuffer[start]);break;
            case 0x1B2: process_userdata (&videobuffer[start], videobuf_len-start);break;
            case 0x100: picture_coding_type=(videobuffer[start+1] >> 3) & 7;break;
          }
        }

        *start=videobuffer; in_size=videobuf_len;

    // get mpeg fps:
    if(sh_video->fps!=picture.fps) if(!force_fps && !telecine){
            mp_msg(MSGT_CPLAYER,MSGL_WARN,"Warning! FPS changed %5.3f -> %5.3f  (%f) [%d]  \n",sh_video->fps,picture.fps,sh_video->fps-picture.fps,picture.frame_rate_code);
            sh_video->fps=picture.fps;
            sh_video->frametime=1.0/picture.fps;
    }

    // fix mpeg2 frametime:
    frame_time=(picture.display_time)*0.01f;
    picture.display_time=100;
    videobuf_len=0;

    telecine_cnt*=0.9; // drift out error
    telecine_cnt+=frame_time-5.0/4.0;
    mp_msg(MSGT_DECVIDEO,MSGL_DBG2,"\r telecine = %3.1f  %5.3f     \n",frame_time,telecine_cnt);

    if(telecine){
        frame_time=1;
        if(telecine_cnt<-1.5 || telecine_cnt>1.5){
            mp_msg(MSGT_DECVIDEO,MSGL_INFO,MSGTR_LeaveTelecineMode);
            telecine=0;
        }
    } else
        if(telecine_cnt>-0.5 && telecine_cnt<0.5 && !force_fps){
            sh_video->fps=sh_video->fps*4/5;
            sh_video->frametime=sh_video->frametime*5/4;
            mp_msg(MSGT_DECVIDEO,MSGL_INFO,MSGTR_EnterTelecineMode);
            telecine=1;
        }
  } else if(video_codec == VIDEO_MPEG4){
        while(videobuf_len<VIDEOBUFFER_SIZE-MAX_VIDEO_PACKET_SIZE){
          int i=sync_video_packet(d_video);
          if(!i) return -1;
          if(!read_video_packet(d_video)) return -1; // EOF
          if(i==0x1B6) break;
        }
        *start=videobuffer; in_size=videobuf_len;
        videobuf_len=0;
  } else if(video_codec == VIDEO_H264){
        int in_picture = 0;
        while(videobuf_len<VIDEOBUFFER_SIZE-MAX_VIDEO_PACKET_SIZE){
          int i=sync_video_packet(d_video);
          int pos = videobuf_len+4;
          if(!i) return -1;
          if(!read_video_packet(d_video)) return -1; // EOF
          if((i&~0x60) == 0x107 && i != 0x107) {
            h264_parse_sps(&picture, &(videobuffer[pos]), videobuf_len - pos);
            if(picture.fps > 0) {
              sh_video->fps=picture.fps;
              sh_video->frametime=1.0/picture.fps;
            }
            i=sync_video_packet(d_video);
            if(!i) return -1;
            if(!read_video_packet(d_video)) return -1; // EOF
          }

          // here starts the access unit end detection code
          // see the mail on MPlayer-dev-eng for details:
          // Date: Sat, 17 Sep 2005 11:24:06 +0200
          // Subject: Re: [MPlayer-dev-eng] [RFC] h264 ES parser problems
          // Message-ID: <20050917092406.GA7699@rz.uni-karlsruhe.de>
          if((i&~0x60) == 0x101 || (i&~0x60) == 0x102 || (i&~0x60) == 0x105)
            // found VCL NAL with slice header i.e. start of current primary coded
            // picture, so start scanning for the end now
            in_picture = 1;
          if (in_picture) {
            i = sync_video_packet(d_video) & ~0x60; // code of next packet
            if(i == 0x106 || i == 0x109) break; // SEI or access unit delim.
            if(i == 0x101 || i == 0x102 || i == 0x105) {
              // assuming arbitrary slice ordering is not allowed, the
              // first_mb_in_slice (golomb encoded) value should be 0 then
              // for the first VCL NAL in a picture
              if (demux_peekc(d_video) & 0x80)
                break;
            }
          }
        }
        *start=videobuffer; in_size=videobuf_len;
        videobuf_len=0;
  }  else if(video_codec == VIDEO_VC1) {
       while(videobuf_len<VIDEOBUFFER_SIZE-MAX_VIDEO_PACKET_SIZE) {
         int i=sync_video_packet(d_video);
         if(!i) return -1;
         if(!read_video_packet(d_video)) return -1; // EOF
         if(i==0x10D) break;
       }
       *start=videobuffer;
       in_size=videobuf_len;
       videobuf_len=0;
  } else {
      // frame-based file formats: (AVI,ASF,MOV)
    in_size=ds_get_packet(d_video,start);
    if(in_size<0) return -1; // EOF
  }


//------------------------ frame decoded. --------------------

    // Increase video timers:
    sh_video->num_frames+=frame_time;
    ++sh_video->num_frames_decoded;

    frame_time*=sh_video->frametime;

    // override frame_time for variable/unknown FPS formats:
    if(!force_fps) switch(demuxer->file_format){
      case DEMUXER_TYPE_GIF:
      case DEMUXER_TYPE_MATROSKA:
      case DEMUXER_TYPE_MNG:
       if(d_video->pts>0 && pts1>0 && d_video->pts>pts1)
         frame_time=d_video->pts-pts1;
        break;
      case DEMUXER_TYPE_TV:
      case DEMUXER_TYPE_MOV:
      case DEMUXER_TYPE_FILM:
      case DEMUXER_TYPE_VIVO:
      case DEMUXER_TYPE_OGG:
      case DEMUXER_TYPE_ASF: {
        double next_pts = ds_get_next_pts(d_video);
        double d= (next_pts != MP_NOPTS_VALUE) ? next_pts - d_video->pts : d_video->pts-pts1;
        if(d>=0){
          if(d>0){
            if((int)sh_video->fps==1000)
              mp_msg(MSGT_CPLAYER,MSGL_V,"\navg. framerate: %d fps             \n",(int)(1.0f/d));
            sh_video->frametime=d; // 1ms
            sh_video->fps=1.0f/d;
          }
          frame_time = d;
        } else {
          mp_msg(MSGT_CPLAYER,MSGL_WARN,"\nInvalid frame duration value (%5.3f/%5.3f => %5.3f). Defaulting to %5.3f sec.\n",d_video->pts,next_pts,d,frame_time);
          // frame_time = 1/25.0;
        }
      }
      break;
      case DEMUXER_TYPE_LAVF:
      case DEMUXER_TYPE_LAVF_PREFERRED:
        if((int)sh_video->fps==1000 || (int)sh_video->fps<=1){
          double next_pts = ds_get_next_pts(d_video);
          double d= (next_pts != MP_NOPTS_VALUE) ? next_pts - d_video->pts : d_video->pts-pts1;
          if(d>=0){
            frame_time = d;
          }
        }
      break;
      case DEMUXER_TYPE_REAL:
        {
          double next_pts = ds_get_next_pts(d_video);
          double d = (next_pts != MP_NOPTS_VALUE) ? next_pts - d_video->pts : d_video->pts - pts1;

          frame_time = (d >= 0 && pts1 > 0) ? d : 0.001;
        }
      break;
    }

    if(video_codec == VIDEO_MPEG12){
        sh_video->pts+=frame_time;
        if(picture_coding_type==1)
            d_video->flags |= 1;
        if(picture_coding_type<=2 && sh_video->i_pts){
            sh_video->pts=sh_video->i_pts;
            sh_video->i_pts=pts;
        } else {
            if(pts){
                if(picture_coding_type<=2) sh_video->i_pts=pts;
                else sh_video->pts=pts;
            }
        }
    } else
        sh_video->pts=d_video->pts;

    if(frame_time_ptr) *frame_time_ptr=frame_time;
    return in_size;
}