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• FFMpeg Android Stagefright SIGSEGV error (h264 decode)

  19 avril 2013, par Sergey Ochkur

  I need to decode h264 file to YUV on Android 2.3+. As I understand I need to communicate with Stagefright, as it`s the only way now, after closing access with OpenMAX IL implementations. I have used FFmpeg 0.10 (and tried 0.9/0.9.1..) for this issue, compiled it with NDK7 (and also tried NDK6b with the same result) :

    ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers
  
    built on Jan 28 2012 14:42:37 with gcc 4.4.3
  
    configuration: --target-os=linux --cross-prefix=arm-linux-androideabi- --arch=arm --cpu=armv7-a --sysroot=/home/grid/Android/Android_NDK/platforms/android-9/arch-arm --disable-avdevice --disable-decoder=h264 --disable-decoder=h264_vdpau --enable-libstagefright-h264 --prefix=build/stagefright/armeabi-v7a --extra-cflags='-Iandroid-source/frameworks/base/include -Iandroid-source/system/core/include -Iandroid-source/frameworks/base/media/libstagefright -Iandroid-source/frameworks/base/include/media/stagefright/openmax -I/home/grid/Android/Android_NDK/sources/cxx-stl/system/include -march=armv7-a -mfloat-abi=softfp -mfpu=neon' --extra-ldflags='-Wl,--fix-cortex-a8 -Landroid-libs -Wl,-rpath-link,android-libs' --extra-cxxflags='-Wno-multichar -fno-exceptions -fno-rtti'
  
    libavutil      51. 34.101 / 51. 34.101
  
    libavcodec     53. 60.100 / 53. 60.100
  
    libavformat    53. 31.100 / 53. 31.100
  
    libavfilter     2. 60.100 /  2. 60.100
  
    libswscale      2.  1.100 /  2.  1.100
  
    libswresample   0.  6.100 /  0.  6.100
  
  Hyper fast Audio and Video encoder
  
  usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

  Hardware : Beagleboard-Xm + TI Android 2.3 (official)

  So, entering next command give me error with 480p :
  ffmpeg -i /sdcard/Video/480p.mp4

  Stopped (signal) ffmpeg -i /sdcard/Video/480p.mp4

  Full Android "answer" from ADB Logcat :
  http://pastebin.com/76JLgtXX

  Android-developers, does anybody know what this error means and how to deal with it ?
  I tried to make DSP window bigger, but with no luck.
  Commands like "stagefright /sdcard/Video/480p.mp4" works fine.

  P.S. Additionally I found that on some bigger files (720p) Android answers next :

  [libstagefright_h264 @ 0xd479b0] Decode failed : 80000000

• reading video mpegts stream from stdin using libavformat libavcodec

  1er février 2012, par D Starkweather

  I'm trying to read video frames from stdin using ffmpeg's libav* lib collection. Simply passing "pipe:0" or "pipe :" as the filename to avformat_open_input_file() in my program does not do the trick. (e.g. cat /dev/video0 | ./myprogram OR ./myprogram < /dev/video0 ; it also fails using file.avi in place of /dev/video0).

  Peeking into ffmpeg.c, I find the following bit of code using tcsetattr() to set the termios :

  struct termios tty;
  
  
  
  if (tcgetattr (0, &tty) == 0) {
  
  oldtty = tty;
  
  restore_tty = 1;
  
  atexit(term_exit);
  
  
  
  tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
  
                        |INLCR|IGNCR|ICRNL|IXON);
  
  tty.c_oflag |= OPOST;
  
  tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
  
  tty.c_cflag &= ~(CSIZE|PARENB);
  
  tty.c_cflag |= CS8;
  
  tty.c_cc[VMIN] = 1;
  
  tty.c_cc[VTIME] = 0;
  
  
  
  tcsetattr (0, TCSANOW, &tty);
  
  }
  
  signal(SIGQUIT, sigterm_handler); /* Quit (POSIX).  */
  
  }
  
  
  
  avformat_network_deinit();
  
  
  
  signal(SIGINT , sigterm_handler); /* Interrupt (ANSI).    */
  
  signal(SIGTERM, sigterm_handler); /* Termination (ANSI).  */
  
  signal(SIGXCPU, sigterm_handler);

  However, when I try this, it appears to have no effect. What settings do I need in the termios struct to continuously read video frames in ?

  Currently, all i am able to do is call av_read_frames a few times (return code 0) before it usually either segfaults or hangs waiting. The buffer usually contains just a blank screen (all black). With any luck, the video buffer will contain the first video frame it comes across, but does not update to the later frames.

  (I'm running this on Debian 6.0) Here's my version of ffmpeg :

  ffmpeg version N-36936-g4cf81d9 Copyright (c) 2000-2012 the FFmpeg
  developers built on Jan 19 2012 20:51:47 with gcc 4.4.5
  configuration : —enable-shared —enable-gray —enable-hardcoded-tables
  —enable-runtime-cpudetect —enable-libmp3lame —enable-libopenjpeg —enable-librtmp —enable-libtheora —enable-libvorbis —enable-libx264 —enable-libxvid —enable-zlib —enable-gpl libavutil 51. 34.101 / 51. 34.101 libavcodec 53. 57.100 /
  53. 57.100 libavformat 53. 30.100 / 53. 30.100 libavdevice 53. 4.100 / 53. 4.100 libavfilter 2. 59.101 / 2. 59.101 libswscale 2. 1.100 / 2. 1.100 libswresample 0. 6.100 /
  0. 6.100 libpostproc 52. 0.100 / 52. 0.100 Hyper fast Audio and Video encoder usage : ffmpeg [options] [[infile options] -i
  infile].

  Thank you very much for any help helpful tips. It is much appreciated.

  D. Grant Starkweather

• Revision 91476 : Introduction de la possibilité de restreindre l’affichage des champs ...

  26 août 2015, par marcimat@… — Log

  Introduction de la possibilité de restreindre l’affichage des champs extras en fonction
  d’une liaison avec un mot clé (​http://contrib.spip.net/Champs-Extras-3#forum480709) en utilisant
  la fonction de simplification restreindre_extras().
  `
  include_spip(’inc/cextras_autoriser’) ;
  restreint les champs ’alpha’ et ’beta’ à la présence d’un lien avec l’un des mots n° 9 ou 10
  restreindre_extras(’article’, array(’ligne’, ’selection_1’), array(9, 10), ’mot’) ;
  `