[FFmpeg-trac] #4051(avformat:new): Assertion error in mux.c with a slow input
FFmpeg
trac at avcodec.org
Tue Oct 21 16:49:31 CEST 2014
#4051: Assertion error in mux.c with a slow input
-------------------------------------+-------------------------------------
Reporter: ubitux | Owner:
Type: defect | Status: new
Priority: important | Component: avformat
Version: | Keywords: mux assert
unspecified | regression
Blocked By: | Blocking:
Reproduced by developer: 0 | Analyzed by developer: 0
-------------------------------------+-------------------------------------
A bit tricky to trigger, I wasn't able to simplify any further. Here is
the first python script you'll need:
{{{
☭ cat <<EOF > /tmp/feed.py
import sys, time
fifo = open(sys.argv[1], 'wb')
frame = '\x00' * (320*240*3)
framecount = 0
for i in range(1000):
print 'write frame #%d' % framecount
fifo.write(frame)
framecount += 1
time.sleep(.1)
EOF
}}}
Create the video FIFO:
{{{
☭ mkfifo /tmp/videofifo
}}}
Start ffmpeg:
{{{
☭ ./ffmpeg -f rawvideo -pixel_format rgb24 -video_size 320x240 -i
/tmp/videofifo -f s32le -ac 2 -ar 44100 -i /dev/zero -map 0:v -map 1:a
-c:v libx264 -c:a aac -strict -2 -y -f matroska /dev/null
ffmpeg version N-67067-g1372c55 Copyright (c) 2000-2014 the FFmpeg
developers
built on Oct 21 2014 16:36:11 with gcc 4.9.1 (GCC) 20140903 (prerelease)
configuration: --enable-gpl --enable-libfribidi --enable-fontconfig
--enable-libfreetype --enable-libx264 --enable-libvorbis --enable-
libmp3lame --enable-libmodplug --enable-libass --enable-libfaac --enable-
nonfree --assert-level=2 --samples=/home/ux/fate-samples --cpu=native
--cc='ccache cc'
libavutil 54. 10.100 / 54. 10.100
libavcodec 56. 8.102 / 56. 8.102
libavformat 56. 9.101 / 56. 9.101
libavdevice 56. 1.100 / 56. 1.100
libavfilter 5. 2.100 / 5. 2.100
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
}}}
While ffmpeg is in stand-by, run the video feeder:
{{{
☭ python2 /tmp/feed.py /tmp/videofifo
write frame #0
write frame #1
write frame #2
write frame #3
write frame #4
...
}}}
After about 50 frames, ffmpeg asserts:
{{{
☭ ./ffmpeg -f rawvideo -pixel_format rgb24 -video_size 320x240 -i
/tmp/videofifo -f s32le -ac 2 -ar 44100 -i /dev/zero -map 0:v -map 1:a
-c:v libx264 -c:a aac -strict -2 -y -f matroska /dev/null
ffmpeg version N-67067-g1372c55 Copyright (c) 2000-2014 the FFmpeg
developers
built on Oct 21 2014 16:36:11 with gcc 4.9.1 (GCC) 20140903 (prerelease)
configuration: --enable-gpl --enable-libfribidi --enable-fontconfig
--enable-libfreetype --enable-libx264 --enable-libvorbis --enable-
libmp3lame --enable-libmodplug --enable-libass --enable-libfaac --enable-
nonfree --assert-level=2 --samples=/home/ux/fate-samples --cpu=native
--cc='ccache cc'
libavutil 54. 10.100 / 54. 10.100
libavcodec 56. 8.102 / 56. 8.102
libavformat 56. 9.101 / 56. 9.101
libavdevice 56. 1.100 / 56. 1.100
libavfilter 5. 2.100 / 5. 2.100
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 1.100 / 1. 1.100
libpostproc 53. 3.100 / 53. 3.100
Input #0, rawvideo, from '/tmp/videofifo':
Duration: N/A, start: 0.000000, bitrate: 46080 kb/s
Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240,
46080 kb/s, 25 tbr, 25 tbn, 25 tbc
Guessed Channel Layout for Input Stream #1.0 : stereo
Input #1, s32le, from '/dev/zero':
Duration: N/A, bitrate: 2822 kb/s
Stream #1:0: Audio: pcm_s32le, 44100 Hz, 2 channels, s32, 2822 kb/s
No pixel format specified, yuv444p for H.264 encoding chosen.
Use -pix_fmt yuv420p for compatibility with outdated media players.
[libx264 @ 0x1a7a080] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
AVX
[libx264 @ 0x1a7a080] profile High 4:4:4 Predictive, level 1.3, 4:4:4
8-bit
[libx264 @ 0x1a7a080] 264 - core 142 r2455 021c0dc - H.264/MPEG-4 AVC
codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options:
cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1
psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1
cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4 threads=6
lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0
bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1
b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25
scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0
qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to '/dev/null':
Metadata:
encoder : Lavf56.9.101
Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv444p,
320x240, q=-1--1, 25 fps, 1k tbn, 25 tbc
Metadata:
encoder : Lavc56.8.102 libx264
Stream #0:1: Audio: aac ([255][0][0][0] / 0x00FF), 44100 Hz, stereo,
fltp, 128 kb/s
Metadata:
encoder : Lavc56.8.102 aac
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
Stream #1:0 -> #0:1 (pcm_s32le (native) -> aac (native))
Press [q] to stop, [?] for help
Assertion pkt->dts == ((int64_t)0x8000000000000000UL) || pkt->dts >= 0
failed at libavformat/mux.c:577
zsh: abort (core dumped) ./ffmpeg -f rawvideo -pixel_format rgb24
-video_size 320x240 -i /tmp/videofif
}}}
I tried {{{-c:v mpeg4}}} instead of {{{-c:v libx264}}} but the assert
didn't occur, so I let it as is.
This is not reproducible with 2.4, so it's a regression. I haven't
bisected yet.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/4051>
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