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• x86inc : create xm# and ym#, analagous to m#

  11 septembre 2013, par Loren Merritt

  x86inc : create xm# and ym#, analagous to m#
  For when we want to mix simd sizes within one function.
  Signed-off-by : Derek Buitenhuis <derek.buitenhuis@gmail.com>
  

  • [DBH] libavutil/x86/x86inc.asm

• ffmpeg 1.0.7 takes minute to create a thumbnail on "broken" video file but other files are seconds to create thumbnail

  8 juillet 2015, par Wiggler Jtag

  I’ve been using ffmpeg 1.0.7 for over 450GB (cca 400 files) for creating thumbnails and grabbing video-file information. It tooks me like 1-2 seconds to create 10 thumbnails from 8GB file. But now I’ve got some ’broken’ video file (672 MB) which creates me 1 thumbnail over a minute, 10 thumbnails its over 10 minutes -> my server burns :

   PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND
  
   9769 www-data  20   0  395m  28m 7212 R 157.0  0.4   0:04.99 ffmpeg

  I opened the file in Windows Media Player and getting blank screen while -> video file is weird, opened it in VLC and it wrote me : Because this AVI file index is broken or missing, seeking will not work correctly. VLC won't repair your file but can temporary fix this problem by building an index in memory. I’ve clicked ’Play as is’ and it plays the video file correctly, however my webserver burns because of FFmpeg and PHP waits for the return from exec(); command. Thumbnails are also created fine after 10 minutes, but how can I fix this problem or to prevent from executing FFmpeg for creating thumbnails on these broken ’video’ files ?

  This is my php :

  $cmd = "ffmpeg -i error.avi 2>&1";
  
  $info = `$cmd`;
  
  echo '<pre>';
  
  print_r($info);
  
  echo '</pre>';

  this is the output I am getting (very quickly)

  ffmpeg version 1.0.7 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Jul 19 2013 07:14:44 with gcc 4.7 (Debian 4.7.2-5)
  
    configuration: --prefix=/usr --extra-cflags='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security ' --extra-ldflags='-Wl,-z,relro' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-libvpx --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-librtmp --enable-avfilter --enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb --enable-libvo-amrwbenc --enable-libaacplus --libdir=/usr/lib/x86_64-linux-gnu --disable-vda --enable-libbluray --enable-libcdio --enable-gnutls --enable-frei0r --enable-openssl --enable-libass --enable-libopus --enable-fontconfig --enable-libfdk-aac --enable-libdc1394 --disable-altivec --dis  libavutil      51. 73.101 / 51. 73.101
  
    libavcodec     54. 59.100 / 54. 59.100
  
    libavformat    54. 29.104 / 54. 29.104
  
    libavdevice    54.  2.101 / 54.  2.101
  
    libavfilter     3. 17.100 /  3. 17.100
  
    libswscale      2.  1.101 /  2.  1.101
  
    libswresample   0. 15.100 /  0. 15.100
  
    libpostproc    52.  0.100 / 52.  0.100
  
  Input #0, avi, from 'error.avi':
  
    Metadata:
  
      encoder         : VirtualDubMod 1.5.10.2 (build 2540/release)
  
    Duration: 01:29:39.32, start: 0.000000, bitrate: 1048 kb/s
  
      Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 640x272 [SAR 1:1 DAR 40:17], 23.98 tbr, 23.98 tbn, 23.98 tbc
  
      Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16, 128 kb/s
  
  At least one output file must be specified

  So it looks like just creating thumbnails is having problems :

  exec("ffmpeg -ss 01:11:43 -i error.avi -vframes 1 -s 616x320 -an output_1.jpg 2>&1");

  Where could be the problem ? Thanks for your suggestions !

  Btw. I am posting this on SO because I’m not sure where it belongs more than here - I think it could be done somehow by PHP but I’m not really sure.

  EDIT : I have added timeout, which "fixes" my problem, but even latest version of FFmpeg 2. stucks on creating thumbnail from broken video files.

  exec("timeout 5s ffmpeg -ss 01:11:43 -i error.avi -vframes 1 -s 616x320 -an output_1.jpg 2>&1");

• How to create an H264 video for specific Libav decoding

  16 octobre 2013, par James491

  I'm creating a program that decodes and displays videos using Libav. I have complete control over the videos the program uses because I make them beforehand. I am able to seek and decode the videos as needed but only after adjusting to a few quirks of x264 encoded videos. For instance, I have to add 8-10 extra frames at the end of my videos to be able to decode and seek to the original last frame. Is it possible to further customize the encoding of an H264 video using ffmpeg or another application, or perhaps some parameters I can initialize in AVFormatContext or AVCodecContext, in order to solve something like decoding the last frames ? Also, are there any specifics I can add to the video file or implement in decoding to decrease seek time, since all seek commands and positions are predetermined ? My current seeking function is just composed of an avformat_seek_file(...) followed by avcodec_flush_buffers(...). I am already seeking to key frames. I am willing to read and learn if all you have is a recommended page or article to investigate.