[FFmpeg-devel] [PATCH] avformat: Add image3 demuxers with format autodetection

[Andreas Cadhalpun]

On 21.07.2014 23:18, Carl Eugen Hoyos wrote:
> Andreas Cadhalpun <andreas.cadhalpun <at> googlemail.com> writes:
>
>> This patch has a strange side effect. With it gst-libav1.0
>> (version 1.3.2) gets compiled incorrectly so that when the
>> plugin is loaded by gstreamer it segfaults:
>> ERROR: Caught a segmentation fault while loading plugin file:
>
> Please provide a backtrace.

Attached.

The problem is that in_plugin->long_name is a null pointer.

You can find the source code here:
http://sources.debian.net/src/gst-libav1.0/1.3.2-1/ext/libav/gstavdemux.c?hl=1942#L1942

Best regards,
Andreas
-------------- next part --------------
gdb -ex run -ex bt -ex "print in_plugin->long_name" -ex continue -ex quit --args /usr/bin/gst-codec-info-1.0 /tmp/buildd/gst-libav1.0-1.3.2/debian/tmp//usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstlibav.so
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Reading symbols from /usr/bin/gst-codec-info-1.0...Reading symbols from /usr/lib/debug/.build-id/a9/31c8248cc61a103e0f6146857c6f8ae4a948e4.debug...done.
done.
Starting program: /usr/bin/gst-codec-info-1.0 /tmp/buildd/gst-libav1.0-1.3.2/debian/tmp//usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstlibav.so
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff601202c in gst_ffmpegdemux_register (plugin=0x62c2c0)
    at gstavdemux.c:1942
1942	    if (!strncmp (in_plugin->long_name, "raw ", 4) ||
#0  0x00007ffff601202c in gst_ffmpegdemux_register (plugin=0x62c2c0)
    at gstavdemux.c:1942
#1  0x00007ffff5ff5e10 in plugin_init (plugin=0x62c2c0) at gstav.c:141
#2  0x00007ffff73d7a17 in gst_plugin_register_func (plugin=0x62c2c0, 
    desc=0x7ffff6223dc0 <gst_plugin_desc>, user_data=0x0) at gstplugin.c:522
#3  0x00007ffff73d9822 in gst_plugin_load_file (
    filename=0x7fffffffe4bd "/tmp/buildd/gst-libav1.0-1.3.2/debian/tmp//usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstlibav.so", error=0x7fffffffe038)
    at gstplugin.c:817
#4  0x0000000000401a0b in main (argc=<optimized out>, argv=<optimized out>)
    at debian/gst-codec-info.c:434
$1 = 0x0
Continuing.

ERROR: Caught a segmentation fault while loading plugin file:
/tmp/buildd/gst-libav1.0-1.3.2/debian/tmp//usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstlibav.so

Please either:
- remove it and restart.
- run with --gst-disable-segtrap --gst-disable-registry-fork and debug.
[Inferior 1 (process 26953) exited with code 0377]