[Libav-user] ffmpeg threading

[Ierum Shanaya]

hi,

I am setting the thread_count as below:

code snippet: In example file -
https://www.ffmpeg.org/doxygen/trunk/demuxing_decoding_8c-example.html
--------------------------------------------------------

int main (int argc, char **argv)

{

int ret = 0, got_frame;

//unsigned long start, end;

int frame_count=0;

char frameStart[50], frameEnd[50];

//FILE *fp;

 SimRoiStart();

//srand((unsigned int)time(NULL));

if (argc != 4 && argc != 5) {

fprintf(stderr, "usage: %s [-refcount=<old|new_norefcount|new_refcount>] "

"input_file video_output_file audio_output_file\n"

"API example program to show how to read frames from an input file.\n"

"This program reads frames from a file, decodes them, and writes decoded\n"

"video frames to a rawvideo file named video_output_file, and decoded\n"

"audio frames to a rawaudio file named audio_output_file.\n\n"

"If the -refcount option is specified, the program use the\n"

"reference counting frame system which allows keeping a copy of\n"

"the data for longer than one decode call. If unset, it's using\n"

"the classic old method.\n"

"\n", argv[0]);

exit(1);

}

 if (argc == 5) {

const char *mode = argv[1] + strlen("-refcount=");

if (!strcmp(mode, "old")) api_mode = API_MODE_OLD;

else if (!strcmp(mode, "new_norefcount")) api_mode =
API_MODE_NEW_API_NO_REF_COUNT;

else if (!strcmp(mode, "new_refcount")) api_mode =
API_MODE_NEW_API_REF_COUNT;

else {

fprintf(stderr, "unknow mode '%s'\n", mode);

exit(1);

}

argv++;

}

src_filename = argv[1];

video_dst_filename = argv[2];

audio_dst_filename = argv[3];

/* register all formats and codecs */

av_register_all();

 /* open input file, and allocate format context */

if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {

fprintf(stderr, "Could not open source file %s\n", src_filename);

exit(1);

}

 /* retrieve stream information */

if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {

fprintf(stderr, "Could not find stream information\n");

exit(1);

}

 if (open_codec_context(&video_stream_idx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >=
0) {

video_stream = fmt_ctx->streams[video_stream_idx];

video_dec_ctx = video_stream->codec;

*//set number of threads to be utilized for video decoding*

* video_dec_ctx->thread_count = 7;*

* video_dec_ctx->thread_type = FF_THREAD_SLICE; //multithreading method set
to slice-based*

video_dst_file = fopen(video_dst_filename, "wb");

if (!video_dst_file) {

fprintf(stderr, "Could not open destination file %s\n", video_dst_filename);

ret = 1;

goto end;

}

.....................
---------------------------------------------------------------

and for compilation the command used is -

gcc -o demuxing_decoding demuxing_decoding.c -lavutil -lavformat -lavcodec
-lz -lavutil -lm -lpthread -lbz2

The threads are not getting created, I have set the thread_count to 7 to
create 8 threads.

I have also tried by setting the thread_count to 0 for automatic thread
creation based on the no of cores.

Any pointers will be helpful.



Thanks,

Ierum

On Mon, Oct 27, 2014 at 9:48 PM, wm4 <nfxjfg at googlemail.com> wrote:

> On Mon, 27 Oct 2014 16:08:33 +0530
> Ierum Shanaya <ierumshanaya85 at gmail.com> wrote:
>
> > Hi,
> >
> > I am trying to run ffmpeg video decoding by creating multiple threads.
> The
> > problem i am facing is that only one thread is created, irrespective of
> > setting the thread_count to 0 or any no like say 2 , 4 etc.
> >
> > I did check the config as below:
> >
> > *it doesnt have --enable pthreads things.. Is this the issue??. *
> > If so, how to set the --enable pthread again in ffmpeg?? Can someone
> please
> > help me understand.
> >
> > I have Ubuntu 12.4 on my system(64 bit)
> >
> > *Output:*
> > -----------------------------------------------------------------
> >
> > ierumshanaya at ubuntu:~/ffmpeg_sources/ffmpeg$ ffmpeg
> > ffmpeg version git-2014-01-05-f5f6e59 Copyright (c) 2000-2014 the FFmpeg
> > developers
> >   built on Jan 22 2014 19:00:25 with gcc 4.6 (Ubuntu/Linaro
> 4.6.3-1ubuntu5)
> >   *configuration*: --prefix=/home/ierumshanaya/ffmpeg_build/lib/pkgconfig
> > --extra-cflags=-I/home/ierumshanaya/ffmpeg_build/include
> > --extra-ldflags=-L/home/ierumshanaya/ffmpeg_build/lib
> > --bindir=/home/ierumshanaya/bin --extra-libs=-ldl --enable-gpl
> > --enable-libass --enable-libfdk-aac --enable-libmp3lame
> --enable-libtheora
> > --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree
> > --enable-x11grab
> >   libavutil      52. 60.100 / 52. 60.100
> >   libavcodec     55. 47.100 / 55. 47.100
> >   libavformat    55. 22.102 / 55. 22.102
> >   libavdevice    55.  5.102 / 55.  5.102
> >   libavfilter     4.  0.103 /  4.  0.103
> >   libswscale      2.  5.101 /  2.  5.101
> >   libswresample   0. 17.104 /  0. 17.104
> >   libpostproc    52.  3.100 / 52.  3.100
> > Hyper fast Audio and Video encoder
> > usage: ffmpeg [options] [[infile options] -i infile]... {[outfile
> options]
> > outfile}...
> > Thanks,
> > Ierum
>
> Are you setting the thread_count before "opening" the decoder?
> _______________________________________________
> Libav-user mailing list
> Libav-user at ffmpeg.org
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>
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