My simple transcoding app hangs, code review requested

Chuck Crisler ccrisler at mutualink.net
Tue Oct 1 14:54:29 PDT 2013 

I am stuck using 0.10.30 and several things have changed. However, here is
what I see.

1. In my 'pad_added' callback, I don't unref the pad. That *could* do it
since you are segfaulting when dealing with pads.

2. style nit - For lines 181 and 183: define constants for 'audio' and
'video', then use those constants and sizeof(const).
3. Get rid of the 'fprintf' and g_print. Instead use GST_XXX for ERROR,
WARN, INFO, DEBUG, LOG. Refer to GstInfo for more debugging support. That
will bring everything together and help you find and fix problems faster
because you will see exactly what happened and where the process got.

That is all I saw. Hope it helps.


On Tue, Oct 1, 2013 at 4:16 PM, Andrey Utkin <andrey.krieger.utkin at gmail.com
> wrote:

> I have derived my code from "Hello world" of Gstreamer Application
> Development Manual.
> The source file is there: https://gist.github.com/krieger-od/6784332
> Compiled with
> gcc main.c -o gstreamer_test `pkg-config --cflags --libs
> gstreamer-1.0` -O0 -g -ggdb
> The application freezes, see its output and gdb backtrace below.
> I think i missed some basic concept(s) because the intention is trivial.
> Please anybody brave check my code.
>
> Command and output:
>
> ./gstreamer_test ~/Downloads/big_buck_bunny_720p_h264.mov bbb_reenc.ts
> Now playing: /home/krieger/Downloads/big_buck_bunny_720p_h264.mov
> Running...
> pad name 'video_0'
> Dynamic pad created, linking demuxer/decoder
> pad name 'audio_0'
> Dynamic pad created, linking demuxer/decoder
> <hangs there. Output file is 0 bytes length>
>
>
> Packages versions: everything related seems 1.2.0
>
>  # equery list '*gst*' | grep '[-]1'
> media-libs/gst-plugins-bad-1.2.0
> media-libs/gst-plugins-base-1.2.0
> media-libs/gst-plugins-good-1.2.0
> media-libs/gst-plugins-ugly-1.2.0
> media-libs/gstreamer-1.2.0
> media-plugins/gst-plugins-a52dec-1.0.5
> media-plugins/gst-plugins-cdparanoia-1.0.5
> media-plugins/gst-plugins-dts-1.0.5
> media-plugins/gst-plugins-dvdread-1.0.5
> media-plugins/gst-plugins-faad-1.0.5
> media-plugins/gst-plugins-flac-1.0.5
> media-plugins/gst-plugins-libav-1.2.0
> media-plugins/gst-plugins-mad-1.0.5
> media-plugins/gst-plugins-meta-1.0-r1
> media-plugins/gst-plugins-mpeg2dec-1.0.5
> media-plugins/gst-plugins-resindvd-1.0.5
> media-plugins/gst-plugins-x264-1.2.0
>
>
> GDB backtraces:
> (gdb) thread apply all bt
>
> Thread 6 (Thread 0x7fe20d30d700 (LWP 22426)):
> #0  0x00007fe2135205ec in pthread_cond_wait () from /lib64/libpthread.so.0
> #1  0x00007fe2137b97af in g_cond_wait () from /usr/lib64/libglib-2.0.so.0
> #2  0x00007fe2119afc33 in gst_collect_pads_chain (pad=0x1a6a490,
> parent=0x1a6e0c0, buffer=0x7fe208003d80)
>     at gstcollectpads.c:2056
> #3  0x00007fe213d20c51 in gst_pad_chain_data_unchecked (pad=0x1a6a490,
> type=4112, data=0x7fe208003d80) at gstpad.c:3711
> #4  0x00007fe213d21714 in gst_pad_push_data (pad=0x19eb860, type=4112,
> data=0x7fe208003d80) at gstpad.c:3941
> #5  0x00007fe213d21c65 in gst_pad_push (pad=0x19eb860,
> buffer=0x7fe208003d80) at gstpad.c:4044
> #6  0x00007fe2112c2de8 in gst_audio_encoder_finish_frame
> (enc=0x1a5a370, buf=0x7fe208003d80, samples=1152)
>     at gstaudioencoder.c:856
> #7  0x00007fe2102f69d4 in gst_ffmpegaudenc_encode_audio () from
> /usr/lib64/gstreamer-1.0/libgstlibav.so
> #8  0x00007fe2102f6fa3 in gst_ffmpegaudenc_handle_frame () from
> /usr/lib64/gstreamer-1.0/libgstlibav.so
> #9  0x00007fe2112c35ab in gst_audio_encoder_push_buffers
> (enc=0x1a5a370, force=0) at gstaudioencoder.c:976
> #10 0x00007fe2112c50ba in gst_audio_encoder_chain (pad=0x19eb630,
> parent=0x1a5a370, buffer=0x7fe208003830)
>     at gstaudioencoder.c:1195
> #11 0x00007fe213d20c51 in gst_pad_chain_data_unchecked (pad=0x19eb630,
> type=4112, data=0x7fe208003830) at gstpad.c:3711
> #12 0x00007fe213d21714 in gst_pad_push_data (pad=0x19eafa0, type=4112,
> data=0x7fe208003830) at gstpad.c:3941
> #13 0x00007fe213d21c65 in gst_pad_push (pad=0x19eafa0,
> buffer=0x7fe208003830) at gstpad.c:4044
> #14 0x00007fe2119a2946 in gst_base_transform_chain (pad=0x19ead70,
> parent=0x1a51000, buffer=0x7fe208003940)
>     at gstbasetransform.c:2237
> #15 0x00007fe213d20c51 in gst_pad_chain_data_unchecked (pad=0x19ead70,
> type=4112, data=0x7fe208003940) at gstpad.c:3711
> #16 0x00007fe213d21714 in gst_pad_push_data (pad=0x19ea6e0, type=4112,
> data=0x7fe208003940) at gstpad.c:3941
> #17 0x00007fe213d21c65 in gst_pad_push (pad=0x19ea6e0,
> buffer=0x7fe208003940) at gstpad.c:4044
> #18 0x00007fe2112b7963 in gst_audio_decoder_push_forward
> (dec=0x1a43110, buf=0x7fe208003940) at gstaudiodecoder.c:876
> #19 0x00007fe2112b8163 in gst_audio_decoder_output (dec=0x1a43110,
> buf=0x7fe208003940) at gstaudiodecoder.c:952
> #20 0x00007fe2112b9215 in gst_audio_decoder_finish_frame
> (dec=0x1a43110, buf=0x7fe208003940, frames=0)
>     at gstaudiodecoder.c:1156
> #21 0x00007fe2102fb4c5 in gst_ffmpegauddec_handle_frame () from
> /usr/lib64/gstreamer-1.0/libgstlibav.so
> #22 0x00007fe2112b97cb in gst_audio_decoder_handle_frame
> (dec=0x1a43110, klass=0x1a41c90, buffer=0x7fe208003830)
>     at gstaudiodecoder.c:1203
> #23 0x00007fe2112b9c5d in gst_audio_decoder_push_buffers
> (dec=0x1a43110, force=0) at gstaudiodecoder.c:1301
> #24 0x00007fe2112ba196 in gst_audio_decoder_chain_forward
> (dec=0x1a43110, buffer=0x0) at gstaudiodecoder.c:1404
> #25 0x00007fe2112bba36 in gst_audio_decoder_chain (pad=0x19ea4b0,
> parent=0x1a43110, buffer=0x7fe208003830)
>     at gstaudiodecoder.c:1672
> #26 0x00007fe213d20c51 in gst_pad_chain_data_unchecked (pad=0x19ea4b0,
> type=4112, data=0x7fe208003830) at gstpad.c:3711
> #27 0x00007fe213d21714 in gst_pad_push_data (pad=0x1a6af80, type=4112,
> data=0x7fe208003830) at gstpad.c:3941
> #28 0x00007fe213d21c65 in gst_pad_push (pad=0x1a6af80,
> buffer=0x7fe208003830) at gstpad.c:4044
> #29 0x00007fe211716f23 in gst_qtdemux_decorate_and_push_buffer
> (qtdemux=0x19f8240, stream=<optimized out>,
>     buf=0x7fe208003830, dts=21333333, pts=21333333, duration=21333333,
> keyframe=1, position=21333333,
>     byte_position=<optimized out>) at qtdemux.c:4109
> #30 0x00007fe211727dd4 in gst_qtdemux_loop_state_movie
> (qtdemux=0x19f8240) at qtdemux.c:4246
> #31 gst_qtdemux_loop (pad=0x19ea280) at qtdemux.c:4323
> #32 0x00007fe213d54d64 in gst_task_func (task=0x1a86000) at gsttask.c:316
> #33 0x00007fe213d55e5f in default_func (tdata=0x1a75520,
> pool=0x1898840) at gsttaskpool.c:70
> ---Type <return> to continue, or q <return> to quit---
> #34 0x00007fe21379fbf8 in g_thread_pool_thread_proxy () from
> /usr/lib64/libglib-2.0.so.0
> #35 0x00007fe21379f325 in g_thread_proxy () from
> /usr/lib64/libglib-2.0.so.0
> #36 0x00007fe21351bda6 in start_thread () from /lib64/libpthread.so.0
> #37 0x00007fe213254abd in clone () from /lib64/libc.so.6
>
> Thread 5 (Thread 0x7fe20ca31700 (LWP 22427)):
> #0  0x00007fe2135205ec in pthread_cond_wait () from /lib64/libpthread.so.0
> #1  0x00007fe20f60c88b in frame_worker_thread () from
> /usr/lib64/libavcodec.so.54
> #2  0x00007fe21351bda6 in start_thread () from /lib64/libpthread.so.0
> #3  0x00007fe213254abd in clone () from /lib64/libc.so.6
>
> Thread 4 (Thread 0x7fe207fff700 (LWP 22428)):
> #0  0x00007fe2135205ec in pthread_cond_wait () from /lib64/libpthread.so.0
> #1  0x00007fe20f60c88b in frame_worker_thread () from
> /usr/lib64/libavcodec.so.54
> #2  0x00007fe21351bda6 in start_thread () from /lib64/libpthread.so.0
> #3  0x00007fe213254abd in clone () from /lib64/libc.so.6
>
> Thread 3 (Thread 0x7fe2077fe700 (LWP 22429)):
> #0  0x00007fe2135205ec in pthread_cond_wait () from /lib64/libpthread.so.0
> #1  0x00007fe20f60c88b in frame_worker_thread () from
> /usr/lib64/libavcodec.so.54
> #2  0x00007fe21351bda6 in start_thread () from /lib64/libpthread.so.0
> #3  0x00007fe213254abd in clone () from /lib64/libc.so.6
>
> Thread 2 (Thread 0x7fe206ffd700 (LWP 22430)):
> #0  0x00007fe2135205ec in pthread_cond_wait () from /lib64/libpthread.so.0
> #1  0x00007fe20f60c88b in frame_worker_thread () from
> /usr/lib64/libavcodec.so.54
> #2  0x00007fe21351bda6 in start_thread () from /lib64/libpthread.so.0
> #3  0x00007fe213254abd in clone () from /lib64/libc.so.6
>
> Thread 1 (Thread 0x7fe2141bb700 (LWP 22425)):
> #0  0x00007fe21324bb73 in poll () from /lib64/libc.so.6
> #1  0x00007fe21377b8d6 in g_main_context_iterate.clone.6 () from
> /usr/lib64/libglib-2.0.so.0
> #2  0x00007fe21377bd2a in g_main_loop_run () from
> /usr/lib64/libglib-2.0.so.0
> #3  0x0000000000401764 in main (argc=3, argv=0x7fff3f0f3728) at main.c:157
>
> --
> Andrey Utkin
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
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