On Sat, 25 Mar 2017 13:01:58 +0100 Michael Niedermayer <mich...@niedermayer.cc> wrote:
> On Sat, Mar 25, 2017 at 12:03:23PM +0100, wm4 wrote: > > On Fri, 24 Mar 2017 18:53:41 +0100 > > Michael Niedermayer <mich...@niedermayer.cc> wrote: > > > > > On Fri, Mar 24, 2017 at 01:47:10PM +0100, wm4 wrote: > > > > async_mutex has is used in a very strange but intentional way: it is > > > > locked by default, and unlocked only in regions that can be run > > > > concurrently. > > > > > > > > If the user was calling API functions to the same context from different > > > > threads (in a safe way), this could unintentionally unlock the mutex on > > > > a different thread than the previous lock operation. It's not allowed by > > > > the pthread API. > > > > > > > > Fix this by emulating a binary semaphore using a mutex and condition > > > > variable. (Posix semaphores are not available on all platforms.) > > > > --- > > > > libavcodec/pthread_frame.c | 41 > > > > +++++++++++++++++++++++++++++++---------- > > > > 1 file changed, 31 insertions(+), 10 deletions(-) > > > > > > this breaks flac > > > > > > make -j12 ffmpeg && ./ffmpeg -i ~/tickets/4421/testwav_cut.wav out.flac ; > > > ./ffmpeg -i out.flac -f null - > > > https://trac.ffmpeg.org/attachment/ticket/4421/testwav_cut.wav > > > > > > Input #0, flac, from 'out.flac': > > > Metadata: > > > ENCODER : Lavf57.67.100 > > > Duration: 00:00:10.00, start: 0.000000, bitrate: 912 kb/s > > > Stream #0:0: Audio: flac, 44100 Hz, stereo, s16 > > > Stream mapping: > > > Stream #0:0 -> #0:0 (flac (native) -> pcm_s16le (native)) > > > Press [q] to stop, [?] for help > > > Output #0, null, to 'pipe:': > > > Metadata: > > > encoder : Lavf57.67.100 > > > Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s > > > Metadata: > > > encoder : Lavc57.86.103 pcm_s16le > > > Assertion ret <= avpkt->size failed at libavcodec/utils.c:2507 > > > Aborted > > > > > > [...] > > > > Actually that was a HTML link. Tried it again with the proper file, > > still cannot reproduce, both commands run successfully. I tried 3 times. > > > > > Please post only things that can be reproduced. > > It reproduces 100% here: > > git log -2 --oneline > 4bf2209f29 pthread_frame: do not attempt to unlock a mutex on the wrong thread > 09ce5519f3 fate/checkasm: fix use of uninitialized memory on hevc_add_res > tests > > make distclean ; ./configure --enable-pthreads --assert-level=2 > make -j12 ffmpeg && ./ffmpeg -y -i ~/tickets/4421/testwav_cut.wav out.flac ; > ./ffmpeg -i out.flac -f null - > > 77700c5eaf9daf4d5d5092af79774882 /home/michael/tickets/4421/testwav_cut.wav > 1fb29c0b2086a7cabf389de647316249 out.flac > > ... > Press [q] to stop, [?] for help > Output #0, null, to 'pipe:': > Metadata: > encoder : Lavf57.67.100 > Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s > Metadata: > encoder : Lavc57.86.103 pcm_s16le > Assertion ret <= avpkt->size failed at libavcodec/utils.c:2507 > Aborted > > 2nd ffmpeg under valgrind > > Output #0, null, to 'pipe:': > Metadata: > encoder : Lavf57.67.100 > Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s > Metadata: > encoder : Lavc57.86.103 pcm_s16le > ==20594== Conditional jump or move depends on uninitialised value(s) > ==20594== at 0xADBE5D: avcodec_decode_audio4 (utils.c:2390) > ==20594== by 0xADC797: do_decode (utils.c:2827) > ==20594== by 0xADD7EF: avcodec_receive_frame (utils.c:2949) > ==20594== by 0x49F99A: process_input_packet (ffmpeg.c:2256) > ==20594== by 0x4A11F8: process_input (ffmpeg.c:4171) > ==20594== by 0x4A362E: transcode (ffmpeg.c:4481) > ==20594== by 0x483B17: main (ffmpeg.c:4740) > ==20594== > ==20594== Conditional jump or move depends on uninitialised value(s) > ==20594== at 0xADC0F5: avcodec_decode_audio4 (utils.c:2497) > ==20594== by 0xADC797: do_decode (utils.c:2827) > ==20594== by 0xADD7EF: avcodec_receive_frame (utils.c:2949) > ==20594== by 0x49F99A: process_input_packet (ffmpeg.c:2256) > ==20594== by 0x4A11F8: process_input (ffmpeg.c:4171) > ==20594== by 0x4A362E: transcode (ffmpeg.c:4481) > ==20594== by 0x483B17: main (ffmpeg.c:4740) > ==20594== > ==20594== Conditional jump or move depends on uninitialised value(s) > ==20594== at 0xADC10D: avcodec_decode_audio4 (utils.c:2507) > ==20594== by 0xADC797: do_decode (utils.c:2827) > ==20594== by 0xADD7EF: avcodec_receive_frame (utils.c:2949) > ==20594== by 0x49F99A: process_input_packet (ffmpeg.c:2256) > ==20594== by 0x4A11F8: process_input (ffmpeg.c:4171) > ==20594== by 0x4A362E: transcode (ffmpeg.c:4481) > ==20594== by 0x483B17: main (ffmpeg.c:4740) > ==20594== > Assertion ret <= avpkt->size failed at libavcodec/utils.c:2507 > It's because ff_thread_decode_frame() does not initialize ret in all code paths, now it works, fixed locally. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel