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• Merge commit ’9d2cee52d37c7340f85a5d41110282aac03e6855’

  27 septembre 2014, par Michael Niedermayer

  Merge commit ’9d2cee52d37c7340f85a5d41110282aac03e6855’
  * commit ’9d2cee52d37c7340f85a5d41110282aac03e6855’ :
  
    configure : Assume a standard-compliant default libc
  See : 170e2fd7c39c430b334ea80a1e4dfb10c6fd1e95
  
  Note, the change is not merged to avoid breaking netbsd and others.
  
  once the netbsd (and any other breakages are dealt with the
  
  else based solution could be used and 170e2fd7c39c430b334ea80a1e4dfb10c6fd1e95
  
  could then be reverted)
  Merged-by : Michael Niedermayer <michaelni@gmx.at>
  

• FFMPEG - errors when combining videos

  1er décembre 2012, par ethrbunny

  I have two .OGG files of similar size, FPS and duration. My goal is to combine them into a side-by-side presentation using FFMPEG. To this end I've tried the following cmd :

  ffmpeg -i subject.ogg -vf "[in]pad=3*iw:3*ih[left] ;movie=clinician.ogg[right] ;[left] [right]overlay=100:0[out]" combined.ogg

  Suffice to say that the resultant video is non-playable. During the combination process FFMPEG prints lots of errors that read like :

  [Parsed_overlay_2 @ 0x1eb7d3e0] Buffer queue overflow, dropping

  What is this telling me ?

  Note :

  • both source files are playable
  • I padded the 'output' to be rather large in an attempt to understand the params
  • the placement of the 2nd video at 100:0 is arbitrary. Once I get the cmd working I'll move it to a better location in the output.
  • both videos began life as .FLV recorded from web cameras. I converted them to .ogg as FFMPEG didn't want to combine two .FLV files. If there is a better route to this, please let me know.

  So - what's wrong with my parameters and what am I doing to cause these FFMPEG errors ?

  EDIT :
  ffmpeg -i clinician.ogg

  Input #0, ogg, from 'clinician.ogg' :
  Duration : 00:05:20.98, start : 0.001000, bitrate : 2273 kb/s
  Stream #0:0 : Video : theora, yuv420p, 500x500 [SAR 1:1 DAR 1:1], 1k tbr, 1k tbn, 1k tbc
  Metadata :
  SERVER : Red5 Server 1.0.0 RC1 $Rev : 4193 $
  CANSEEKTOEND : true
  ENCODER : Lavf54.31.100
  Stream #0:1 : Audio : vorbis, 8000 Hz, stereo, s16
  Metadata :
  SERVER : Red5 Server 1.0.0 RC1 $Rev : 4193 $
  CANSEEKTOEND : true
  ENCODER : Lavf54.31.100

  ffmpeg -i subject.ogg

  Input #0, ogg, from 'subject.ogg' :
  Duration : 00:05:17.60, start : 0.001000, bitrate : 1341 kb/s
  Stream #0:0 : Video : theora, yuv420p, 300x300 [SAR 1:1 DAR 1:1], 83.33 tbr, 1k tbn, 1k tbc
  Metadata :
  SERVER : Red5 Server 1.0.0 RC1 $Rev : 4193 $
  CANSEEKTOEND : true
  ENCODER : Lavf54.31.100
  Stream #0:1 : Audio : vorbis, 8000 Hz, stereo, s16
  Metadata :
  SERVER : Red5 Server 1.0.0 RC1 $Rev : 4193 $
  CANSEEKTOEND : true
  ENCODER : Lavf54.31.100

• Decoder crashes after ffmpeg upgrade

  5 mai 2014, par Igor R.

  Recently I upgraded ffmpeg from 0.9 to 1.0 (tested on Win7x64 and on iOS), and now avcodec_decode_video2 seagfaults. Long story short : the crash occurs every time the video dimensions change (eg. from 320x240 to 160x120 or vice versa).

  I receive mpeg4 video stream from some proprietary source and decode it like this :

  // once, during initialization:
  
  AVCodec *codec_ = avcodec_find_decoder(CODEC_ID_MPEG4);
  
  AVCodecContext ctx_ = avcodec_alloc_context3(codec_);
  
  avcodec_open2(ctx_, codec_, 0);
  
  AVPacket packet_;
  
  av_init_packet(&packet_);
  
  AVFrame picture_ = avcodec_alloc_frame();
  
  
  
  // on every frame:
  
  int got_picture;
  
  packet_.size = size;
  
  packet_.data = (uint8_t *)buffer;
  
  avcodec_decode_video2(ctx_, picture_, &got_picture, &packet_);

  Again, all the above had worked flawlessly until I upgraded to 1.0. Now every time the frame dimensions change - avcodec_decode_video2 crashes. Note that I don’t assign width/height in AVCodecContext - neither in the beginning, nor when the stream changes - can it be the reason ?

  I’d appreciate any idea !

  Update : setting ctx_.width and ctx_.height doesn’t help.

  Update2 : just before the crash I get the following log messages :

  mpeg4, level 24 : "Found 2 unreleased buffers !".
  level 8 : "Assertion i < avci->buffer_count failed at libavcodec/utils.c:603"

  Update3 upgrading to 1.1.2 fixed this crash. The decoder is able again to cope with dimensions change on the fly.