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• Why does Android kill a process spawned by the developed application ?

  23 octobre 2013, par uprego

  I have a weird problem that I posted as a comment in Understanding Android Tight loops / Spin-On-Suspend error without any useful further comment.

  Let be here the reproduced comment :

  Is it possible for this to be happening also to android native codes, abstracting
  
   which piece of software would be causing it? It's the only reason I know ffmpeg 
  
  (static binary custom compilation, n2.0.1 tag mint as it clones) is failing to me
  
   on some devices and not in others (but fails in no device when launched over a v
  
  algrind!! that, am now supposing, traps frequently the inner program)

  The problem, briefly, is that a compiled ffmpeg n2.0.1 is running OK in emulator and a Sony device, but failing with a segmentation violation in a Samsung device. The program was ran then from valgrind in that Samsung device, with no fail.

  • I have some clues about what could be happening here. But do you know what is happening ?
  • Can this Samsung phone run this ffmpeg compilation the same good the emulator and the Sony phone do ? If not, what are the next steps (trying - when possible - to avoid the use of the NDK) ?

• C program cannot find function which included in header file

  17 juin 2013, par Juneyoung Oh

  I made program like this.

    1 #include 
  
    2 #include 
  
    3 #include 
  
    4 #include "libavformat/avformat.h"
  
    5 
  
    6 int main (int argc, char* argv[]){
  
    7         av_register_all();
  
    8         return 0;
  
    9 }

  My header file located in

  root@ubuntu:/home/juneyoungoh/getDuration# find / -name "avformat.h"
  
  /root/ffmpeg/libavformat/avformat.h
  
  /usr/local/include/libavformat/avformat.h

  then I run with gcc getDuration.c , but I show message like below.

  root@ubuntu:/home/juneyoungoh/getDuration# gcc getDuration.c 
  
  /tmp/ccwjonqH.o: In function `main':
  
  getDuration.c:(.text+0x10): undefined reference to `av_register_all'
  
  collect2: ld returned 1 exit status

  Frankly, I do not have any idea what makes this.

  Thanks for your answers.

  ========================== edited #1 ===========================

  when I "ls /usr/local/lib", I get this.

  root@ubuntu:/home/juneyoungoh/getDuration# ls /usr/local/lib/
  
  libavcodec.a   libavutil.a    libopus.la       libvpx.a   python2.7
  
  libavdevice.a  libfdk-aac.a   libpostproc.a    libx264.a
  
  libavfilter.a  libfdk-aac.la  libswresample.a  libyasm.a
  
  libavformat.a  libopus.a      libswscale.a     pkgconfig

  you can see libavformat.a in the very first of the last line.

  so if I command like what you suggest, I get below.

  /root/ffmpeg/libavformat/vqf.c:244: undefined reference to `av_free_packet'
  
  /usr/local/lib//libavformat.a(vqf.o): In function `add_metadata':
  
  /root/ffmpeg/libavformat/vqf.c:58: undefined reference to `av_malloc'
  
  /root/ffmpeg/libavformat/vqf.c:64: undefined reference to `av_dict_set'
  
  /usr/local/lib//libavformat.a(vqf.o): In function `vqf_read_header':
  
  /root/ffmpeg/libavformat/vqf.c:148: undefined reference to `av_dict_set'
  
  /root/ffmpeg/libavformat/vqf.c:208: undefined reference to `av_log'
  
  /root/ffmpeg/libavformat/vqf.c:216: undefined reference to `av_malloc'
  
  /root/ffmpeg/libavformat/vqf.c:170: undefined reference to `av_log'
  
  /root/ffmpeg/libavformat/vqf.c:121: undefined reference to `av_log'
  
  /root/ffmpeg/libavformat/vqf.c:184: undefined reference to `av_log'
  
  /root/ffmpeg/libavformat/vqf.c:136: undefined reference to `av_log'
  
  /usr/local/lib//libavformat.a(wavenc.o): In function `wav_write_trailer':
  
  /root/ffmpeg/libavformat/wavenc.c:210: undefined reference to `av_rescale'
  
  /usr/local/lib//libavformat.a(wavenc.o): In function `wav_write_packet':
  
  /root/ffmpeg/libavformat/wavenc.c:181: undefined reference to `av_log'

  It is too long, so I just post little part of that.

  I think all link of libavformat has been broken, But I do not know

  what can I do to fix that link.

  I have installed that their official link said.

  https://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuideQuantal

• Tools for investigating video corruption — ffmpeg / libavcodec

  11 juillet 2013, par Gopherkhan

  In my current work I'm trying to encode some images to h264 video using the FFMPEG's C library. The resulting video plays fine in VLC, but has no preview image. The video can play in VLC and Mplayer on ubuntu, but won't play on Mac or PC (in fact, it causes a "VTDecoderXPCService quit unexpectedly" error on Mac).

  If I run the resulting file through FFMPEG using the command line, the resulting file has a preview image, and plays correctly everywhere.

  Apparently the file that I get out of the program is corrupt in some weird place, but I don't have any output during my compilation or run to indicate where. I can't share my code at the moment (work code isn't open source yet :-( ), but I have tried a number of things :

  1. Writing only header and trailer data (av_write_trailer) and no frames
  2. writing frames only minus the trailer (using avcodec_encode_video2 and av_write_frame)
  3. Adjusting our time_base and frame pts values to encode only one frame per second
  4. Removing all variable frame rate code
  5. Numerous other variants that I won't bother you with here

  In creating my project, I've also followed the following tutorials :

  • Dr. Anger's FFMPEG tutorial
  • FFmpeg's Own Tutorials
  • An older tutorial from FFmpeg

  And consulted the deprecated ffmpeg functions list

  And compiled FFMPEG on ubuntu according to the official doc

  But every run of the program runs into the exact same problem.

  My question is, is there anything obvious that causes a programmatic run of FFMpeg to differ from a console run (e.g., an incomplete finalization, some threading issues, etc.) ? Like some obvious reason that a console run could repair a corrupted file ? Or is there a decent tool/method for inspecting a video file and finding the point of corruption ?