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• ffmpeg : add a data size threshold for muxing queue size

  15 octobre 2020, par Jan Ekström

  ffmpeg : add a data size threshold for muxing queue size
  This way the old max queue size limit based behavior for streams
  
  where each individual packet is large is kept, while for smaller
  
  streams more packets can be buffered (current default is at 50
  
  megabytes per stream).
  For some explanation, by default ffmpeg copies packets from before
  
  the appointed seek point/start time and puts them into the local
  
  muxing queue. Before, it getting utilized was much less likely
  
  since as soon as the filter chain was initialized, the encoder
  
  (and thus output stream) was also initialized.
  Now, since we will be pushing the encoder initialization to when the
  
  first AVFrame is decoded and filtered - which only happens after
  
  the exact seek point is hit as packets are ignored until then -
  
  this queue will be seeing much more usage.
  In more layman's terms, this attempts to fix cases such as where :
  
   seek point ends up being 5 seconds before requested time.
  
   audio is set to copy, and thus immediately begins filling the
  
    muxing queue.
  
   video is being encoded, and thus all received packets are skipped
  
    until the requested time is hit.
  

  • [DH] doc/ffmpeg.texi
  • [DH] fftools/ffmpeg.c
  • [DH] fftools/ffmpeg.h
  • [DH] fftools/ffmpeg_opt.c

• Decoding RIMM streaming file format

  10 septembre 2011, par Thomas

  I want to decode the video (visual) frames within a Blackberry RIMM file. So far I have a parser, and some corresponding container documentation from RIM. 

  The video codec is H264 and is explicitly set on the device using one of the video.encodings properties. However, FFMPEG is not able to decode the frames and this is driving me nuts.

  Edit 1 : The issues seems to be lack of SPS and PPS in the frames, and artificially inserting them have proven unsuccessful so far (all grey image). Blackberry 9700 sends

  0x00 0x00 0x ?? 0x ?? 0xType

  where Type is according to table 7-1 in the H264 spec (I and P frames). We believe the 0x ?? 0x ?? represent the size of the frame, however the size does not always correspond to the size found by the parser (the parser seems to be working correctly).

  I have a windows decoder codec from blackberry, called mc_demux_mp2_ds.ax, and can play some MPEG-4 files captured the same way, but it is a binary for windows. And the H264 files will not play either way. I am aware of previous attempts. The capture url for javax.microedition.media.Manager is

  encoding=video-3gpp_width=176_height=144_video_codec=H264_audio_codec=AAC

  and I am writing to an output stream. Some example files here.

  Edit 2 :Turns out that about 3-4 of the 12-15 available video capture modes are flat out failing and refusing to output data, even in the simplest of test applications. So any working solution should implement MPEG-4, H264 and H263 in both AMR and AAC, in so getting fallback alternatives when one sound codec and/or resolution fails. Reboots, hangs and what not litters the Blackberry video implementation and vary from firmware to firmware ; total suckage.

• build : rename version.h to libavutil/ffversion.h

  29 novembre 2013, par Timothy Gu

  build : rename version.h to libavutil/ffversion.h
  Also the libavutil/ffversion.h will be installed.
  Rationale :
  
  * Applications might want to know FFmpeg’s version besides the individual
  
    libraries’.
  
  * Avoids file name clash between FFmpeg’s ./version.h and lib*/version.h when
  
    a library source file includes both and is compiled on an out-of-tree build.
  Fixes #1769.
  Signed-off-by : Timothy Gu <timothygu99@gmail.com>
  
  Reviewed-by : James Almer <jamrial@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] .gitignore
  • [DH] Makefile
  • [DH] cmdutils.c
  • [DH] doc/APIchanges
  • [DH] ffprobe.c
  • [DH] libavutil/Makefile
  • [DH] libavutil/version.h