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• Upper limit on FFMPEG/libx264 frame sizes ?

  22 mars 2014, par Chaotic

  I'm trying to use FFMPEG to transcode a video with very large frames (4096 x 4096). It's a short video - just under two minutes, but the source video file is 15.8GB. (The video is an animation designed to be projected onto planetarium domes.)

  The source file is a Quicktime MOV containing uncompressed Photo-JPEG images (with audio, too). When I tell FFMPEG to transcode my MOV file into an MP4 file, it simply says :

  Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height

  Not very helpful, but yes, I've verified that all of the parameters are correct and/or defaults. In fact, if I change the requested output size to 2048x2048, then everything works just fine. That's why I suspect that there's an upper bound in the encoder.

  I am kerflummoxed. Any suggestions that result in a successful transcode will be greatly appreciated. (At this point I am also willing to consider alternatives to FFMPEG.)

  The Facts

  I run FFMPEG from a script :

  set srcFile=%1
  
  set dstFile=%srcFile:.mov=.mp4%
  
  
  
  ffmpeg -i %srcFile% -movflags faststart -q:a 0 -q:v 0 -pix_fmt yuv420p -sws_flags gauss -s 4096x4096 %dstFile%

  The Output

      ffmpeg version N-50911-g9efcfbe Copyright (c) 2000-2013 the FFmpeg developers
  
      built on Mar 13 2013 21:26:48 with gcc 4.7.2 (GCC)
  
      configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --ena
  
  ble-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  
    libavutil      52. 19.100 / 52. 19.100
  
    libavcodec     55.  0.100 / 55.  0.100
  
    libavformat    55.  0.100 / 55.  0.100
  
    libavdevice    54.  4.100 / 54.  4.100
  
    libavfilter     3. 45.103 /  3. 45.103
  
    libswscale      2.  2.100 /  2.  2.100
  
    libswresample   0. 17.102 /  0. 17.102
  
    libpostproc    52.  2.100 / 52.  2.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'also-sprach-zarathustra-4k.mov':
  
    Metadata:
  
      major_brand     : qt
  
      minor_version   : 537199360
  
      compatible_brands: qt
  
      creation_time   : 2013-01-11 23:41:30
  
    Duration: 00:01:40.57, start: 0.000000, bitrate: 1357694 kb/s
  
      Stream #0:0(eng): Audio: pcm_s16be (twos / 0x736F7774), 44100 Hz, stereo, s16, 1411 kb/s
  
      Metadata:
  
        creation_time   : 2013-01-11 23:41:30
  
        handler_name    : Apple Alias Data Handler
  
      Stream #0:1(eng): Video: mjpeg (jpeg / 0x6765706A), yuvj420p, 4096x4096 [SAR 1:1 DAR 1:1], 1356281 kb/s, 30 fps, 30
  
  tbr, 3k tbn, 3k tbc
  
      Metadata:
  
        creation_time   : 2013-01-11 23:41:30
  
        handler_name    : Apple Alias Data Handler
  
  File 'also-sprach-zarathustra-4k.mp4' already exists. Overwrite ? [y/N] y
  
  using SAR=1/1
  
  [libx264 @ 003b9c80] frame MB size (256x256) > level limit (36864)
  
  [libx264 @ 003b9c80] DPB size (4 frames, 262144 mbs) > level limit (2 frames, 184320 mbs)
  
  [libx264 @ 003b9c80] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 FMA3 LZCNT BMI1 BMI2
  
  x264 [error]: malloc of size 17305600 failed
  
  Output #0, mp4, to 'also-sprach-zarathustra-4k.mp4':
  
    Metadata:
  
      major_brand     : qt
  
      minor_version   : 537199360
  
      compatible_brands: qt
  
      Stream #0:0(eng): Video: h264, yuv420p, 4096x4096 [SAR 1:1 DAR 1:1], q=-1--1, 90k tbn, 30 tbc
  
      Metadata:
  
        creation_time   : 2013-01-11 23:41:30
  
        handler_name    : Apple Alias Data Handler
  
      Stream #0:1(eng): Audio: none, 44100 Hz, stereo, s16, 128 kb/s
  
      Metadata:
  
        creation_time   : 2013-01-11 23:41:30
  
        handler_name    : Apple Alias Data Handler
  
  Stream mapping:
  
    Stream #0:1 -> #0:0 (mjpeg -> libx264)
  
    Stream #0:0 -> #0:1 (pcm_s16be -> libvo_aacenc)
  
  Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height

  PS : Yes, for those playing at home, it is the theme to 2001 - A Space Odyssey. You can see a 1K YouTube version here : 2001 - A Fulldome Space Odyssey And yes, in a planetarium with a good sound system, it is absolutely EPIC.

• MPEG-DASH create initialization segment

  3 novembre 2014, par static

  I’m segmenting the video capture of the desktop using ffmpeg -segment and sending them over network in order to be served to clients and to be played using dash.js. The problem is that the player is searching for the initialization segment and i don’t seem to be able to figure out how to create it.
  I create the segments using this ffmpeg command :

  ffmpeg -rtbufsize 1500M -f dshow -r 15 -i video="UScreenCapture"
  
  -flags +global_header -vcodec libvpx -crf 10 -quality good -keyint_min 15 -g 15
  
  -cpu-used 3 -b:v 1000k -qmin 10 -qmax 42  -threads 2 -vf scale=-1:480 -bufsize 1
  
  500 -map 0 -f stream_segment -segment_time 2 -segment_format webm http://localho
  
  st:3000/stream/22/%03d

  The manifest that i create for the stream looks something like this :

  <mpd xmlns="urn:mpeg:dash:schema:mpd:2011" type="dynamic" availabilitystarttime="2014-06-19T07:47:40.079Z" minbuffertime="PT0S" profiles="urn:mpeg:dash:profile:isoff-live:2011" suggestedpresentationdelay="PT40S" maxsegmentduration="PT2.000S" minimumupdateperiod="PT1000M">
  
  <period bitstreamswitching="true" start="PT0S">
  
  <adaptationset mimetype="video/webm" segmentalignment="true" startwithsap="1" maxwidth="1280" maxheight="720" maxframerate="15">
  
  <contentcomponent contenttype="video"></contentcomponent>
  
  <segmenttemplate presentationtimeoffset="0" timescale="90000" media="$Number$/" duration="180000" startnumber="0"></segmenttemplate>
  
  <representation width="853" height="480" framerate="15" bandwidth="1000000" codecs="vp8"></representation>
  
  </adaptationset>
  
  </period>
  
  </mpd> 

  The player debugging mode prints the following things :

  Getting the request for time: 0 dash.all.js:2073
  
  Index for time 0 is 0 dash.all.js:2073
  
  Waiting for more video buffer before starting playback. dash.all.js:2073
  
  BufferController video seek: 0 dash.all.js:2073
  
  Marking a special seek for initial video playback. dash.all.js:2073
  
  Start searching for initialization. dash.all.js:2073
  
  Perform init search: stream/22/ dash.all.js:2073
  
  Getting the request for time: 0 dash.all.js:2073
  
  Index for time 0 is 0 dash.all.js:2073
  
  Data changed - loading the video fragment for time: 0 dash.all.js:2073
  
  Getting the request for time: 0 

  How can i create the initialization segment for the generated segments ? I can’t seem to be able to get it to work.

• libavformat : Remove a misleading/incorrect comment

  3 janvier 2015, par Martin Storsjö

  libavformat : Remove a misleading/incorrect comment
  This comment can be traced back to the initial commit from 2001,
  
  and it seemed to be misleading/incorect already back then. (It
  
  was used for normal, non-raw file formats already then.)
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavformat/avformat.h