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• How to convert VP8 track with different frame resolution to h264

  13 septembre 2016, par Nikita

  I have a .webm file with VP8 track, recorded from WebRTC stream by external service (TokBox Archiving). The stream is adaptive, so each frame in track could have different resolution. Most players (in webkit browsers) use video resolution from track description (which is always 640x480) and scale frames to this resolution. Firefox and VLC player uses real frame resolution, changing video resolution respectively.

  I want to achieve 2 goals :

  1. play this video in Internet Explorer 9+ without additional plugin installation.
  2. change frames resolution to one fixed resolution, so the video will look identically in different browsers.

  So, my plan is :

  • extract frames from source webm file to images with real frame resolution (e.g. PNG or BMP) (how could I do that ?)
  • find max width and max height of images
  • add black padding to images, so smaller frames will be in the center of a new frame (of size MAX_WIDHTxMAX_HEIGHT)
  • combine images to h264 track using ffmpeg

  Is all correct ? How can I achieve this ? Can this algorithm be optimized some way ?

  I tried ffmpeg to extract images, but it does not parse real frame resolution, using resolution from track header.
  I think some libwebm functions can help me (to parse frame headers and extract images). Maybe someone has some code snippets to do this ?

  Example .webm (download source, do not play google-converted version) : https://drive.google.com/file/d/0BwFZRvYNn9CKcndhMzlVa0psX00/view?usp=sharing

  Official description of adaptive stream from TokBox support : https://support.tokbox.com/hc/en-us/community/posts/206241666-Archived-video-resolution-is-supposed-to-be-720x1280-but-reports-as-640x480

• Set RTSP/UDP buffer size in FFmpeg/LibAV

  9 décembre 2016, par chuckleplant

  Note : I’m aware ffmpeg and libav are different libraries. This is a problem common to both.

  Disclaimer : Duplicate of SO question marked as answered but actually didn’t give a proper solution.

  ---

  Insufficient UDP buffer size causes broken streams for several high resolution video streams. In LibAV/FFMPEG it’s possible to set the udp buffer size for udp urls (udp ://...) by appending some options (buffer_size) to it.

  However, for RTSP urls this is not supported.

  These are the only solutions I’ve found :

  • Rebuilding ffmpeg/libav changing the UDP_MAX_PKT_SIZE in the udp.c source file.
  • Using a nasty hack to find and modify the required value, by casting some private structs.
  • Using a different decoding library (proposed solution to aforementioned related SO question).

  None of these is actually a solution. From what I found it should be possible to use the API’s AVOptions to find and set this value. Or else, the AVDictionary.

  It’s very difficult to find how to set these throughout the documentation of either libav or ffmpeg.

  Update :

  The following patches have been submited to Libav tackling this topic, thanks to Libav developer @lu_zero :

  • Add a buffer_size option
  • Map the urloptions to AVOptions

  Which should offer a hint on how to implement those, still these are not yet available through the official stable API.

• ffmpeg conversion from Flac to Ogg produces corrupted files

  8 avril 2021, par experimental

  i transcoded flac files to ogg using this command

  


  ffmpeg -i input.flac -c:a libvorbis -b:a 500k  output.ogg


  


  yes i use 500k to keep the highest quality possible, some of the files are ok, but some of them can not be played - Unsupported format or corrupted file says the foobar - also my icecast streamer cant read it. So there is something wrong with the files.

  


  I believed it was due to the high bitrate so I tried

  


  ffmpeg -i input.flac -c:a libvorbis -b:a 320k  output.ogg


  


  the same happened, some files were ok, some were not playable.
so I tried again with default using this command

  


  ffmpeg -i input.flac -c:a libvorbis output.ogg


  


  same thing. some files were ok, some were corrupted and not playable.

  


  i have no clue why.

  


  both flac and ogg are in the same family, what happened during the transcoding that it became a corrupted file ?

  


  the spectral analysis does not show anything wrong - here it the ogg https://prnt.sc/115zdjl, here is the original flac https://prnt.sc/115zegw

  


  i am really interested what is going on and how to make it work ?

  


  can anyone explain ?

  


  here is complete log

  


      C:\Users\lukas.kotatko>ffmpeg -i "\\192.168.0.128\lukas\online radio resources\Atma FM playlists\channel 1\flac lossless\Tuu\One Thousand Years\02 One Thousand Years.flac" -c:a libvorbis -b:a 500k "\\192.168.0.128\lukas\online radio resources\Atma FM playlists\channel 1\flac lossless\Tuu\One Thousand Years\02 One Thousand Years [500k test].ogg"
ffmpeg version 4.3.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 10.2.1 (GCC) 20200726
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libgsm --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Input #0, flac, from '\\192.168.0.128\lukas\online radio resources\Atma FM playlists\channel 1\flac lossless\Tuu\One Thousand Years\02 One Thousand Years.flac':
  Metadata:
    GENRE           : Tribal / Ambient
    ORGANIZATION    : Waveform Records
    ISRC            : 01101-2
    COMMENT         : US reissue featuring the six original tracks plus two taken from the Invocation album.
    MUSICBRAINZ_RELEASEGROUPID: 737d0518-3dc2-36b3-9419-282c0ade0e50
    ORIGINALDATE    : 1993
    ORIGINALYEAR    : 1993
    RELEASETYPE     : album
    MUSICBRAINZ_ALBUMID: f6339129-f662-43a1-93df-2f20540f73cc
    ALBUM           : One Thousand Years
    BARCODE         : 789060110125
    MUSICBRAINZ_ALBUMARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
    album_artist    : Tuu
    ALBUMARTISTSORT : Tuu
    ASIN            : B00005B9TT
    SCRIPT          : Latn
    RELEASESTATUS   : official
    LABEL           : Waveform Records
    CATALOGNUMBER   : 01101-2
    RELEASECOUNTRY  : US
    DATE            : 2001-05-08
    TOTALDISCS      : 1
    disc            : 1
    TOTALTRACKS     : 8
    MEDIA           : CD
    MUSICBRAINZ_TRACKID: aef9824d-e4a6-4ae6-aebe-50a83dd14f71
    TITLE           : One Thousand Years
    MUSICBRAINZ_ARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
    ARTIST          : Tuu
    ARTISTSORT      : Tuu
    ARTISTS         : Tuu
    MUSICBRAINZ_RELEASETRACKID: 621c9da6-a85d-3f8b-b485-5e6f74a60cd0
    track           : 2
    TRACKTOTAL      : 8
    DISCTOTAL       : 1
  Duration: 00:08:03.67, start: 0.000000, bitrate: 792 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
    Stream #0:1: Video: mjpeg (Baseline), yuvj420p(pc, bt470bg/unknown/unknown), 600x600 [SAR 1:1 DAR 1:1], 90k tbr, 90k tbn, 90k tbc (attached pic)
    Metadata:
      comment         : Cover (front)
Stream mapping:
  Stream #0:1 -> #0:0 (mjpeg (native) -> theora (libtheora))
  Stream #0:0 -> #0:1 (flac (native) -> vorbis (libvorbis))
Press [q] to stop, [?] for help
[swscaler @ 0000015307581a00] deprecated pixel format used, make sure you did set range correctly
[ogg @ 00000153073f1680] Frame rate very high for a muxer not efficiently supporting it.
Please consider specifying a lower framerate, a different muxer or -vsync 2
Output #0, ogg, to '\\192.168.0.128\lukas\online radio resources\Atma FM playlists\channel 1\flac lossless\Tuu\One Thousand Years\02 One Thousand Years [500k test].ogg':
  Metadata:
    GENRE           : Tribal / Ambient
    ORGANIZATION    : Waveform Records
    ISRC            : 01101-2
    COMMENT         : US reissue featuring the six original tracks plus two taken from the Invocation album.
    MUSICBRAINZ_RELEASEGROUPID: 737d0518-3dc2-36b3-9419-282c0ade0e50
    ORIGINALDATE    : 1993
    ORIGINALYEAR    : 1993
    RELEASETYPE     : album
    MUSICBRAINZ_ALBUMID: f6339129-f662-43a1-93df-2f20540f73cc
    ALBUM           : One Thousand Years
    BARCODE         : 789060110125
    MUSICBRAINZ_ALBUMARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
    album_artist    : Tuu
    ALBUMARTISTSORT : Tuu
    ASIN            : B00005B9TT
    SCRIPT          : Latn
    RELEASESTATUS   : official
    LABEL           : Waveform Records
    CATALOGNUMBER   : 01101-2
    RELEASECOUNTRY  : US
    DATE            : 2001-05-08
    TOTALDISCS      : 1
    disc            : 1
    TOTALTRACKS     : 8
    MEDIA           : CD
    MUSICBRAINZ_TRACKID: aef9824d-e4a6-4ae6-aebe-50a83dd14f71
    TITLE           : One Thousand Years
    MUSICBRAINZ_ARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
    ARTIST          : Tuu
    ARTISTSORT      : Tuu
    ARTISTS         : Tuu
    MUSICBRAINZ_RELEASETRACKID: 621c9da6-a85d-3f8b-b485-5e6f74a60cd0
    track           : 2
    TRACKTOTAL      : 8
    DISCTOTAL       : 1
    encoder         : Lavf58.45.100
    Stream #0:0: Video: theora (libtheora), yuv420p(progressive), 600x600 [SAR 1:1 DAR 1:1], q=2-31, 200 kb/s, 90k fps, 90k tbn, 90k tbc (attached pic)
    Metadata:
      DESCRIPTION     : Cover (front)
      encoder         : Lavc58.91.100 libtheora
      GENRE           : Tribal / Ambient
      ORGANIZATION    : Waveform Records
      ISRC            : 01101-2
      MUSICBRAINZ_RELEASEGROUPID: 737d0518-3dc2-36b3-9419-282c0ade0e50
      ORIGINALDATE    : 1993
      ORIGINALYEAR    : 1993
      RELEASETYPE     : album
      MUSICBRAINZ_ALBUMID: f6339129-f662-43a1-93df-2f20540f73cc
      ALBUM           : One Thousand Years
      BARCODE         : 789060110125
      MUSICBRAINZ_ALBUMARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
      ALBUMARTIST     : Tuu
      ALBUMARTISTSORT : Tuu
      ASIN            : B00005B9TT
      SCRIPT          : Latn
      RELEASESTATUS   : official
      LABEL           : Waveform Records
      CATALOGNUMBER   : 01101-2
      RELEASECOUNTRY  : US
      DATE            : 2001-05-08
      TOTALDISCS      : 1
      DISCNUMBER      : 1
      TOTALTRACKS     : 8
      MEDIA           : CD
      MUSICBRAINZ_TRACKID: aef9824d-e4a6-4ae6-aebe-50a83dd14f71
      TITLE           : One Thousand Years
      MUSICBRAINZ_ARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
      ARTIST          : Tuu
      ARTISTSORT      : Tuu
      ARTISTS         : Tuu
      MUSICBRAINZ_RELEASETRACKID: 621c9da6-a85d-3f8b-b485-5e6f74a60cd0
      TRACKNUMBER     : 2
      TRACKTOTAL      : 8
      DISCTOTAL       : 1
    Stream #0:1: Audio: vorbis (libvorbis), 44100 Hz, stereo, fltp (16 bit), 500 kb/s
    Metadata:
      encoder         : Lavc58.91.100 libvorbis
      GENRE           : Tribal / Ambient
      ORGANIZATION    : Waveform Records
      ISRC            : 01101-2
      DESCRIPTION     : US reissue featuring the six original tracks plus two taken from the Invocation album.
      MUSICBRAINZ_RELEASEGROUPID: 737d0518-3dc2-36b3-9419-282c0ade0e50
      ORIGINALDATE    : 1993
      ORIGINALYEAR    : 1993
      RELEASETYPE     : album
      MUSICBRAINZ_ALBUMID: f6339129-f662-43a1-93df-2f20540f73cc
      ALBUM           : One Thousand Years
      BARCODE         : 789060110125
      MUSICBRAINZ_ALBUMARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
      ALBUMARTIST     : Tuu
      ALBUMARTISTSORT : Tuu
      ASIN            : B00005B9TT
      SCRIPT          : Latn
      RELEASESTATUS   : official
      LABEL           : Waveform Records
      CATALOGNUMBER   : 01101-2
      RELEASECOUNTRY  : US
      DATE            : 2001-05-08
      TOTALDISCS      : 1
      DISCNUMBER      : 1
      TOTALTRACKS     : 8
      MEDIA           : CD
      MUSICBRAINZ_TRACKID: aef9824d-e4a6-4ae6-aebe-50a83dd14f71
      TITLE           : One Thousand Years
      MUSICBRAINZ_ARTISTID: e05a42e7-60a3-4d2d-983c-51dc4eb67cad
      ARTIST          : Tuu
      ARTISTSORT      : Tuu
      ARTISTS         : Tuu
      MUSICBRAINZ_RELEASETRACKID: 621c9da6-a85d-3f8b-b485-5e6f74a60cd0
      TRACKNUMBER     : 2
      TRACKTOTAL      : 8
      DISCTOTAL       : 1
frame=    1 fps=0.1 q=-0.0 Lsize=   25860kB time=00:08:03.66 bitrate= 438.0kbits/s speed=44.6x
video:8kB audio:25721kB subtitle:0kB other streams:0kB global headers:7kB muxing overhead: 0.511663%