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• Prevent suspend event when streaming video via HTML video tag

  24 septembre 2014, par jasongullickson

  I seem to be having the opposite problem of most people who are streaming video using the HTML video tag ; I’m saturating the client with data.

  When playing a long video served via ffserver (webm container) everything works great but eventually the browser (Chrome in this case) will begin throwing "suspend" events. After a number of these ( 50-100), a "stalled" event will fire and playback will stop.

  I believe the problem is that once Chrome has buffered a certain amount of video it goes into "suspend" and stops downloading more data. I’ve tested this theory by throttling the speed at which video data is delivered, and if I keep the delivered frame rate close to the playback rate, I can prevent this from happening, but of course deliberately holding back server performance isn’t ideal.

  What I’m looking for is either a way to suppress this "suspend" behavior altogether, or alternatively a way to respond to the event that prevents the eventual "stalled" state.

  Presumably the browser at some point exits the "suspend" state and begins requesting data again, but I haven’t actually observed this occurring. I’m using a chain of mpeg2 -> ffmpeg -> ffserver to stream the video so if the browser is attempting to resume loading data I don’t see the request in my application. I could use a proxy or a sniffer to watch for the traffic but I would expect that maybe there is an ffserver log that can tell me the same thing ? In any event if it’s attempting to resume the download it’s failing, and there’s no indication server-side that there’s a reason for the request to fail (in fact I can pull up the same video feed from ffserver and see it playing correctly).

  So I feel like I’ve isolated this to a client-side playback issue, and one where the browser is voluntarily giving up on loading the data, but I’m not sure how to convince it to "not do that", or at least attempt to resume when it runs the buffer dry.

• How to fix : Frame rate differs from source after encoding certain mp4 videos to wmv

  25 juin 2019, par hpenhp

  I’m having trouble with a usually working ffmpeg script for encoding mp4 and more to wmv. The goal is to keep it like the original, except for the resolution (smaller) and the format (wmv).

  When it usually works for a lot of videos, on some of them it doesn’t... and i would like to understand and avoid that.

  I tried several things, forcing the framerate for the output, using -vsync 2 option, -vsync 0 also.. noone of that fixed the issue.

  An other thing, worth adding, is that the fps value from media info is good (24 fps) on the output like the input, but through the M$ windows explorer, it says 30 frames per sec, and when you play the video you see that the text that was matching the input doesn’t match the output any more (because of the fps mismatching).

  Below the script i use :

  ffmpeg -threads auto -i input.mp4 -s 480*320 -b:v 1000k -vcodec msmpeg4 -acodec wmav2 -f asf output.wmv

  Here is the ffmpeg log :

  ffmpeg version 3.4.1-1~16.04.york0 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.5) 20160609
  
    configuration: --prefix=/usr --extra-version='1~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  
    WARNING: library configuration mismatch
  
    avcodec     configuration: --prefix=/usr --extra-version='1~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared --enable-version3 --disable-doc --disable-programs --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libtesseract --enable-libvo_amrwbenc
  
    libavutil      55. 78.100 / 55. 78.100
  
    libavcodec     57.107.100 / 57.107.100
  
    libavformat    57. 83.100 / 57. 83.100
  
    libavdevice    57. 10.100 / 57. 10.100
  
    libavfilter     6.107.100 /  6.107.100
  
    libavresample   3.  7.  0 /  3.  7.  0
  
    libswscale      4.  8.100 /  4.  8.100
  
    libswresample   2.  9.100 /  2.  9.100
  
    libpostproc    54.  7.100 / 54.  7.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from './test_2k-24__hq_960x540.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42mp41isomavc1
  
      creation_time   : 2019-05-27T14:37:50.000000Z
  
    Duration: 01:28:52.80, start: 0.000000, bitrate: 1232 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, smpte170m), 960x540, 1091 kb/s, 24 fps, 24 tbr, 24 tbn, 48 tbc (default)
  
      Metadata:
  
        creation_time   : 2019-05-27T14:37:50.000000Z
  
        handler_name    : L-SMASH Video Handler
  
        encoder         : AVC Coding
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 137 kb/s (default)
  
      Metadata:
  
        creation_time   : 2019-05-27T14:37:50.000000Z
  
        handler_name    : L-SMASH Audio Handler
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> msmpeg4v3 (msmpeg4))
  
    Stream #0:1 -> #0:1 (aac (native) -> wmav2 (native))
  
  Press [q] to stop, [?] for help
  
  Output #0, asf, to '/nas/copiedetravail/test_2k-24__hq_960x540.mp4.wmv':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42mp41isomavc1
  
      WM/EncodingSettings: Lavf57.83.100
  
      Stream #0:0(und): Video: msmpeg4v3 (msmpeg4) (MP43 / 0x3334504D), yuv420p(progressive), 480x320, q=2-31, 1000 kb/s, 24 fps, 1k tbn, 24 tbc (default)
  
      Metadata:
  
        creation_time   : 2019-05-27T14:37:50.000000Z
  
        handler_name    : L-SMASH Video Handler
  
        encoder         : Lavc57.107.100 msmpeg4
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/1000000 buffer size: 0 vbv_delay: -1
  
      Stream #0:1(und): Audio: wmav2 (a[1][0][0] / 0x0161), 48000 Hz, stereo, fltp, 128 kb/s (default)
  
      Metadata:
  
        creation_time   : 2019-05-27T14:37:50.000000Z
  
        handler_name    : L-SMASH Audio Handler
  
        encoder         : Lavc57.107.100 wmav2
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 31 times
  
  frame=  228 fps=0.0 q=2.0 size=     291kB time=00:00:09.45 bitrate= 252.4kbits/s speed=18.9x    
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 1 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
      Last message repeated 1 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
      Last message repeated 1 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
      Last message repeated 5 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 2 times
  
  frame=  449 fps=449 q=2.0 size=     663kB time=00:00:18.98 bitrate= 286.2kbits/s speed=  19x    
  
  frame=  629 fps=418 q=1.6 size=    1307kB time=00:00:26.16 bitrate= 409.2kbits/s speed=17.4x    
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 30 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 7 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 2 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 34 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 1 times
  
  frame=  821 fps=410 q=2.0 size=    1960kB time=00:00:34.26 bitrate= 468.7kbits/s speed=17.1x    
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 71 times
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 2 dct coefficients to -127..127
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 82 times
  
  frame= 1026 fps=409 q=2.0 size=    2695kB time=00:00:42.96 bitrate= 513.8kbits/s speed=17.1x    
  
  [msmpeg4 @ 0x5648e407cb60] warning, clipping 1 dct coefficients to -127..127
  
      Last message repeated 102 times
  
  frame= 1202 fps=400 q=1.6 size=    3754kB time=00:00:50.13 bitrate= 613.4kbits/s speed=16.7x  
  
  ......
  
  frame=127987 fps=301 q=2.0 Lsize=  753842kB time=01:28:52.77 bitrate=1158.0kbits/s speed=12.6x    
  
  video:650704kB audio:83244kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.710554%

  EDIT :
  My workaround was to encode to MPEG, doing this, i’m able to read my file and the frame rate is same as source. If someone knows why it couldn’t keep the original framerate in wmv, i’m still interested to know.

• How to speed-up ffmpeg encoding for the 'qtrle' codec

  20 mai 2024, par userxxxxxxxxx

  Need you guys help for
that I'm facing kinda limit of performance to encode clips with the codec 'qtrle'.

  


  In short,

  


  

  1. Is there GPU option or technic for the qtrle encoding by GPU ?
Can I get ANY of technic for qtrle ?

  


  2. Does NVMe m.2 upgrade helps performance for ffmpeg concat and encoding ? (Currently SKHynix P41 M.2 1TB on PCIe 4 board)

  


  


  (Several multiple times of re-encoding betewwen clips again again again in one loop, so that I cannot use h254 stuff.)