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• FFMpeg generated m3u8 segmented videos takes forever to start playing

  20 novembre 2014, par Michael Gaylord

  I am using ffmpeg to generate a segmented list of files in order to stream them to an iOS app. The list of files is generated fine but when it comes time to play them, the video needs to be downloaded in its entirety before playback starts. This behaviour seems to be the case on iOS, Safari and VLC.

  Does anybody know why this is happening and how I can improve the performance of playback ? I have complete control over how the files are recorded in iOS, as well as how they are processed. Here is a sample stream :

  http://www.bytesizecreations.com/storie-test/hls.m3u8

  Here are my ffmpeg commands to generate the segments from the file :

  ffmpeg -i joined.ts -flags -global_header -vcodec copy -acodec copy -map 0 -f segment -segment_time 2 -segment_list hls.m3u8 -segment_list_size 999999 -segment_format mpegts out%03d.ts

  Here is the output of ffprobe on the file :

    libavutil      54.  7.100 / 54.  7.100
  
    libavcodec     56.  1.100 / 56.  1.100
  
    libavformat    56.  4.101 / 56.  4.101
  
    libavdevice    56.  0.100 / 56.  0.100
  
    libavfilter     5.  1.100 /  5.  1.100
  
    libavresample   2.  1.  0 /  2.  1.  0
  
    libswscale      3.  0.100 /  3.  0.100
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  0.100 / 53.  0.100
  
  Input #0, mpegts, from 'joined.ts':
  
    Duration: 00:00:07.96, start: 1.441667, bitrate: 3899 kb/s
  
    Program 1 
  
      Metadata:
  
        service_name    : Service01
  
        service_provider: FFmpeg
  
      Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p, 1280x720, 24 fps, 24 tbr, 90k tbn, 180k tbc
  
      Stream #0:1[0x101](und): Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp, 222 kb/s

• Why MP4 generated through FFmpeg API can't be played in the Windows Media Player ?

  2 septembre 2021, par James

  I encoded some frames into a MP4 using FFmpeg API, but the MP4 could't be played in the Windows Media Player.

  


  By comparison with the normal MP4 using ffprobe, I found that the FOURCC of the problematic MP4 is 'H264' while the normal MP4 is 'AVC1'.
According to H.264 Video Types, 'AVC1' has start codes but 'H264' hasn't.I also learned that we shoud manually add sps and pps before H.264 stream when demuxing a MP4.

  


  Now I don't know how to add start code or sps/pps to my MP4, please give me a hand.
How I should do to generate a MP4 which can be played in the Windows Media Player ?

  


  I have tried to add h264 bitstream filter but it didn't work. The code below :

  


   AVBitStreamFilterContext *bsfc = NULL;
bsfc = av_bitstream_filter_init("h264_mp4toannexb");
if (bsfc == NULL) {
            printf("bsfc is NULL\n");
}
        
av_bitstream_filter_filter(bsfc, codec_ctx, NULL, &(pkt->data), &(pkt->size), pkt->data, pkt->size, 0);

av_bitstream_filter_close(bsfc);


  


  After a lot of trying, I found that manually adding sps and pps to codec_ctx->extradata effective :

  


  unsigned char sps_pps[23] = { 0x00, 0x00, 0x00, 0x01, 0x67, 0x64, 0x00, 0x29, 0xac, 0x1b, 0x1a, 0x12, 0xe0, 0x51, 0x90,
                              0x00, 0x00, 0x00, 0x01, 0x68, 0xea, 0x43, 0xcb };
codec_ctx->extradata_size = 23;
codec_ctx->extradata = (uint8_t*)av_malloc(23 + AV_INPUT_BUFFER_PADDING_SIZE);
if (codec_ctx->extradata == NULL) {
    printf("could not av_malloc the video params extradata!\n");
    ERR_NULL_EXIT
    }
memcpy(codec_ctx->extradata, sps_pps, 23);


  


  The code above refered to an answer of @szatmary

  


  Now generated MP4 can be played in Windows Media Player. But a new question emerges because I don't konw what correct value of sps/pps is. It cause that the width and height of frame presented in the Windows Explorer is incorrect. So I need to set the correct sps/pps. I also read the document of sps/pps but get confused because some parameters have variable bits. So can anybody tell me how to set the sps/pps correctly ?

  


• build system : fix dependency generation

  8 octobre 2015, par Christophe Gisquet

  build system : fix dependency generation
  When trying to build the binary dct-test under MSYS2/Win64, the
  
  makefile rule does not have the SUBDIR in the target for its
  
  object file.
  Consequently, modifications to various include files (e.g. C ones)
  
  do not trigger a recompilation.
  When tracing the dependency generating, the dependency generation
  
  has this strange content (linebreak inserted) :
  
  sed -e "/^#.*/d" -e "s,^ []*dct\.o,libavcodec/dct.o," \
  
   > libavcodec/dct-test.d
  For some reason, the $(*F) has weird content. It looks simpler to
  
  use $(@F) instead of $(*F)\.o, although this was tested on one
  
  single version of make.
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] configure