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• Issues with encoded video in Chrome playback

  4 novembre 2022, par Michael Joseph Aubry

  Chrome is very particular about how a video is encoded. An issue I am facing with a specific type of video is seeked either does not get called at all or at least within a 20s period of time within certain frames.

  


  I can consistently repeat this issue using this muxer https://github.com/redbrain/ytdl-core-muxer/blob/main/index.js

  


  When I paint each frame in puppeteer Lambda there are certain frames where either seeked never gets called or the 20s timeout is called before the frame can resolve.

  


  Here is an example of a log sequence for this particular frame that fails

  


  When I re-encode this video, simply by running ffmpeg -i VIDEO_URL then try with the new one there are no issues.

  


  In order to see the differences on a frame level I run ffprobe -show_frames goodvideo.mp4 > good.txt && ffprobe -show_frames badvideo.mp4 > bad.txt and here is what I see with the frames around the 117s mark where the first sign of corruption occurs

  


  Good Frame @ 117s

  


  [FRAME]
media_type=video
stream_index=0
key_frame=0
pts=7020013
pts_time=117.000217
pkt_dts=7020013
pkt_dts_time=117.000217
best_effort_timestamp=7020013
best_effort_timestamp_time=117.000217
pkt_duration=1001
pkt_duration_time=0.016683
pkt_pos=27029408
pkt_size=1741
width=1920
height=1080
pix_fmt=yuv420p
sample_aspect_ratio=1:1
pict_type=B
coded_picture_number=7014
display_picture_number=0
interlaced_frame=0
top_field_first=0
repeat_pict=0
color_range=tv
color_space=bt709
color_primaries=bt709
color_transfer=bt709
chroma_location=left
[/FRAME]


  


  Bad Frame @ 117s

  


  [FRAME]
media_type=video
stream_index=0
key_frame=0
pts=117000
pts_time=117.000000
pkt_dts=117000
pkt_dts_time=117.000000
best_effort_timestamp=117000
best_effort_timestamp_time=117.000000
pkt_duration=16
pkt_duration_time=0.016000
pkt_pos=20592998
pkt_size=18067
width=1920
height=1080
pix_fmt=yuv420p
sample_aspect_ratio=1:1
pict_type=P
coded_picture_number=7011
display_picture_number=0
interlaced_frame=0
top_field_first=0
repeat_pict=0
color_range=tv
color_space=bt709
color_primaries=bt709
color_transfer=bt709
chroma_location=left
[/FRAME]


  


  Does anyone know the differences and why the bad frame is causing my rendering function to have issues seeking ?

  


  This is how I am muxing the bad video, Im trying to avoid re-encoding, but by re-encoding it seems to fix the issue. Are there any settings I can apply to avoid re-encoding while making the video more durable on Chrome ?

  


  // default export: the ffmpeg muxer
const ytmux = (link, options: any = {}) => {
  const result = new stream.PassThrough({
    highWaterMark: options.highWaterMark || 1024 * 512
  });

  ytdl.getInfo(link, options).then((info: videoInfo) => {
    let audioStream: Readable = ytdl.downloadFromInfo(info, {
      ...options,
      quality: "highestaudio"
    });
    let videoStream: Readable = ytdl.downloadFromInfo(info, {
      ...options,
      quality: "highestvideo"
    });
    // create the ffmpeg process for muxing
    let ffmpegProcess: any = cp.spawn(
      ffmpegPath.path,
      [
        // supress non-crucial messages
        "-loglevel",
        "8",
        "-hide_banner",
        // input audio and video by pipe
        "-i",
        "pipe:3",

        "-i",
        "pipe:4",

        // map audio and video correspondingly
        "-map",
        "0:v",
        "-map",
        "1:a",

        // no need to change the codec
        "-c",
        "copy",

        // Allow output to be seekable, which is needed for mp4 output
        "-movflags",
        "frag_keyframe+empty_moov",

        "-fflags",
        "+genpts",

        "-f",
        "matroska",

        "pipe:5"
      ],
      {
        // no popup window for Windows users
        windowsHide: true,
        stdio: [
          // silence stdin/out, forward stderr,
          "inherit",
          "inherit",
          "inherit",
          // and pipe audio, video, output
          "pipe",
          "pipe",
          "pipe"
        ]
      }
    );

    audioStream.pipe(ffmpegProcess.stdio[4]);
    videoStream.pipe(ffmpegProcess.stdio[3]);
    ffmpegProcess.stdio[5].pipe(result);
  });
  return result;
};


  


• Why there is no AVFrame->data[2] data when decode h264 by ffmpeg use "h264_cuvid"

  27 juillet 2017, par Wu NL

  env : ubuntu 16.04 64 bit ; ffmpeg 3.3.2 build whih cuda cuvid libnpp...
  use ffmpeg cmd : ffmpeg -vsync 0 -c:v h264_cuvid -i test.264 -f rawvideo test.yuv works fine, the generated yuv file is ok.
  BUT When I decode this 264 file by my code use ’h264_cuvid’ decoder, something problem happens, this is my code :

  #include 
  
  
  
  #define __STDC_CONSTANT_MACROS
  
  
  
  #ifdef _WIN32
  
  //Windows
  
  extern "C"
  
  {
  
  #include "libavcodec/avcodec.h"
  
  };
  
  #else
  
  //Linux...
  
  #ifdef __cplusplus
  
  extern "C"
  
  {
  
  #endif
  
  #include <libavcodec></libavcodec>avcodec.h>
  
  #ifdef __cplusplus
  
  };
  
  #endif
  
  #endif
  
  
  
  
  
  //test different codec
  
  #define TEST_H264  1
  
  #define TEST_HEVC  0
  
  
  
  int main(int argc, char* argv[])
  
  {
  
      AVCodec *pCodec;
  
      AVCodecContext *pCodecCtx= NULL;
  
      AVCodecParserContext *pCodecParserCtx=NULL;
  
  
  
      FILE *fp_in;
  
      FILE *fp_out;
  
      AVFrame *pFrame;
  
  
  
      const int in_buffer_size=4096;
  
      unsigned char in_buffer[in_buffer_size + FF_INPUT_BUFFER_PADDING_SIZE]= {0};
  
      unsigned char *cur_ptr;
  
      int cur_size;
  
      AVPacket packet;
  
      int ret, got_picture;
  
  
  
  
  
  #if TEST_HEVC
  
      enum AVCodecID codec_id=AV_CODEC_ID_HEVC;
  
      char filepath_in[]="bigbuckbunny_480x272.hevc";
  
  #elif TEST_H264
  
      AVCodecID codec_id=AV_CODEC_ID_H264;
  
      char filepath_in[]="2_60_265to264.264";
  
  #else
  
      AVCodecID codec_id=AV_CODEC_ID_MPEG2VIDEO;
  
      char filepath_in[]="bigbuckbunny_480x272.m2v";
  
  #endif
  
  
  
      char filepath_out[]="mainSend.yuv";
  
      int first_time=1;
  
  
  
  
  
      //av_log_set_level(AV_LOG_DEBUG);
  
  
  
      avcodec_register_all();
  
  
  
  //    pCodec = avcodec_find_decoder(codec_id);
  
      pCodec = avcodec_find_decoder_by_name("h264_cuvid");
  
      if (!pCodec)
  
      {
  
          printf("Codec not found\n");
  
          return -1;
  
      }
  
      pCodecCtx = avcodec_alloc_context3(pCodec);
  
      if (!pCodecCtx)
  
      {
  
          printf("Could not allocate video codec context\n");
  
          return -1;
  
      }
  
  
  
      pCodecParserCtx=av_parser_init(pCodec->id);
  
      if (!pCodecParserCtx)
  
      {
  
          printf("Could not allocate video parser context\n");
  
          return -1;
  
      }
  
  
  
      if (avcodec_open2(pCodecCtx, pCodec, NULL) &lt; 0)
  
      {
  
          printf("Could not open codec\n");
  
          return -1;
  
      }
  
      //Input File
  
      fp_in = fopen(filepath_in, "rb");
  
      if (!fp_in)
  
      {
  
          printf("Could not open input stream\n");
  
          return -1;
  
      }
  
      //Output File
  
      fp_out = fopen(filepath_out, "wb");
  
      if (!fp_out)
  
      {
  
          printf("Could not open output YUV file\n");
  
          return -1;
  
      }
  
  
  
      pFrame = av_frame_alloc();
  
      av_init_packet(&amp;packet);
  
  
  
      while (1)
  
      {
  
  
  
          cur_size = fread(in_buffer, 1, in_buffer_size, fp_in);
  
          if (cur_size == 0)
  
              break;
  
          cur_ptr=in_buffer;
  
  
  
          while (cur_size>0)
  
          {
  
  
  
              int len = av_parser_parse2(
  
                            pCodecParserCtx, pCodecCtx,
  
                            &amp;packet.data, &amp;packet.size,
  
                            cur_ptr, cur_size,
  
                            AV_NOPTS_VALUE, AV_NOPTS_VALUE, AV_NOPTS_VALUE);
  
  
  
              cur_ptr += len;
  
              cur_size -= len;
  
  
  
              if(packet.size==0)
  
                  continue;
  
  
  
              //Some Info from AVCodecParserContext
  
              printf("[Packet]Size:%6d\t",packet.size);
  
              switch(pCodecParserCtx->pict_type)
  
              {
  
              case AV_PICTURE_TYPE_I:
  
                  printf("Type:I\tNumber:%4d\n",pCodecParserCtx->output_picture_number);
  
                  break;
  
              case AV_PICTURE_TYPE_P:
  
                  printf("Type:P\t");
  
                  break;
  
              case AV_PICTURE_TYPE_B:
  
                  printf("Type:B\t");
  
                  break;
  
              default:
  
                  printf("Type:Other\t");
  
                  break;
  
              }
  
              printf("Number:%4d\n",pCodecParserCtx->output_picture_number);
  
              AVFrame* myFrame = av_frame_alloc();
  
              ret = avcodec_decode_video2(pCodecCtx, myFrame, &amp;got_picture, &amp;packet);
  
              if (ret &lt; 0)
  
              {
  
                  printf("Decode Error.\n");
  
                  return ret;
  
              }
  
              if (got_picture)
  
              {
  
                  if(first_time)
  
                  {
  
                      printf("\nCodec Full Name:%s\n",pCodecCtx->codec->long_name);
  
                      printf("width:%d\nheight:%d\n\n",pCodecCtx->width,pCodecCtx->height);
  
                      first_time=0;
  
                  }
  
                  //Y, U, V
  
                  for(int i=0; iheight; i++)
  
                  {
  
                      fwrite(myFrame->data[0]+myFrag-g>linesize[0]*i,1,myFrame->width,fp_out);
  
                  }
  
                  for(int i=0; iheight/2; i++)
  
                  {
  
                      fwrite(myFrame->data[1]+myFrag-g>linesize[1]*i,1,myFrame->width/2,fp_out);
  
                  }
  
                  for(int i=0; iheight/2; i++)
  
                  {
  
                      fwrite(myFrame->data[2]+myFrag-g>linesize[2]*i,1,myFrame->width/2,fp_out);
  
                  }
  
  //                printf("pframe's width height %d %d\t key frame %d\n",myFrame->width,myFrame->height,myFrame->key_frame);
  
                  printf("Succeed to decode 1 frame!\n");
  
                  av_frame_free(&amp;myFrame);
  
              }
  
          }
  
  
  
      }
  
  
  
      fclose(fp_in);
  
      fclose(fp_out);
  
  
  
  
  
      av_parser_close(pCodecParserCtx);
  
  
  
      av_frame_free(&amp;pFrame);
  
      avcodec_close(pCodecCtx);
  
      av_free(pCodecCtx);
  
  
  
      return 0;
  
  }

  In this demo code, I call h264_cuvid by vcodec_find_decoder_by_name("h264_cuvid");
  BUT the code crash at fwrite(myFrame->data[2]+myFrag-g>linesize[2]*i,1,myFrame->width/2,fp_out);
  So after debug with codeblocks, I found that there is no data in myFrame->data[2] codeblocks watching window

  Any suggestion ? thanks !

• Improve whileloading() vs. canplaythrough / onload under HTML5 (with support for HTTP range/partial requests). onload() may fire early, followed by numerous whileloading() requests during playback as the HTML5 audio object requests and buffers more audio ranges (eg., 0-10 seconds), eventually matching the total sound duration. (There is no bytes loaded / total, that I’m aware of, to report here, so it’s 0 / 1 and then 0.375 / 1, for example. I suppose I could use integer values, to be "safe", in the future.)

  21 juin 2012, par Scott Schiller

  m script/soundmanager2-jsmin.js m script/soundmanager2-nodebug-jsmin.js m script/soundmanager2-nodebug.js m script/soundmanager2.js Improve whileloading() vs. canplaythrough / onload under HTML5 (with support for HTTP range/partial requests). onload() may fire early, followed by numerous (...)