[FFmpeg-trac] #6330(undetermined:new): Strange behavior with native FFmpeg AAC encoder, when converting audio to mono
FFmpeg
trac at avcodec.org
Fri May 26 03:10:34 EEST 2017
#6330: Strange behavior with native FFmpeg AAC encoder, when converting audio to
mono
-------------------------------------+-------------------------------------
Reporter: edumj | Owner:
Type: defect | Status: new
Priority: normal | Component:
Version: unspecified | undetermined
Keywords: aac | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
-------------------------------------+-------------------------------------
Comment (by edumj):
Hi!
You can try with any video, also with this 2:
[https://samples.ffmpeg.org/sub/starwarssub2.vob]
[https://samples.ffmpeg.org/MPEG-VOB/ClosedCaptions/Starship_Troopers.vob]
Command line:
{{{
ffmpeg -i "starwarssub2.vob" -c:v libx264 -preset medium -b:v 750k
-profile:v baseline -level 3.0 -pix_fmt yuv420p -c:a aac -b:a 64k
-ac 1 "starwarssub2 64k mono.mp4"
}}}
Full output:
{{{
ffmpeg version N-85091-g23ae3cc Copyright (c) 2000-2017 the FFmpeg
developers
built with gcc 6.3.0 (GCC)
configuration: --enable-gpl --enable-version3 --enable-cuda --enable-
cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc
--enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
--enable-gnutls --enable-iconv --enable-libass --enable-libbluray
--enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme
--enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264
--enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy
--enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame
--enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-
libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-
libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma
--enable-zlib
libavutil 55. 57.100 / 55. 57.100
libavcodec 57. 88.100 / 57. 88.100
libavformat 57. 70.100 / 57. 70.100
libavdevice 57. 5.100 / 57. 5.100
libavfilter 6. 81.100 / 6. 81.100
libswscale 4. 5.100 / 4. 5.100
libswresample 2. 6.100 / 2. 6.100
libpostproc 54. 4.100 / 54. 4.100
Input #0, mpeg, from 'starwarssub2.vob':
Duration: 00:00:38.31, start: 2891.089167, bitrate: 7911 kb/s
Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg, top
first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0:1[0x28]: Subtitle: dvd_subtitle
Stream #0:2[0x80]: Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s
Stream #0:3[0x81]: Audio: ac3, 48000 Hz, 5.1(side), fltp, 448 kb/s
Stream #0:4[0x82]: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s
Stream #0:5[0x20]: Subtitle: dvd_subtitle
Stream #0:6[0x21]: Subtitle: dvd_subtitle
Stream #0:7[0x22]: Subtitle: dvd_subtitle
Stream #0:8[0x23]: Subtitle: dvd_subtitle
Stream #0:9[0x24]: Subtitle: dvd_subtitle
Stream #0:10[0x25]: Subtitle: dvd_subtitle
Stream #0:11[0x26]: Subtitle: dvd_subtitle
Stream #0:12[0x27]: Subtitle: dvd_subtitle
Stream #0:13[0x29]: Subtitle: dvd_subtitle
Stream #0:14[0x2a]: Subtitle: dvd_subtitle
Stream #0:15[0x2b]: Subtitle: dvd_subtitle
Stream #0:16[0x2c]: Subtitle: dvd_subtitle
Stream #0:17[0x2d]: Subtitle: dvd_subtitle
Stream #0:18[0x2e]: Subtitle: dvd_subtitle
Stream #0:19[0x2f]: Subtitle: dvd_subtitle
File 'starwarssub2 64k mono.mp4' already exists. Overwrite ? [y/N] Stream
mapping:
Stream #0:0 -> #0:0 (mpeg2video (native) -> h264 (libx264))
Stream #0:2 -> #0:1 (ac3 (native) -> aac (native))
Press [q] to stop, [?] for help
[ac3 @ 00000000025d85e0] frame sync error
Error while decoding stream #0:2: Invalid data found when processing input
[aac @ 0000000002b115c0] Queue input is backward in time
[libx264 @ 0000000002b10760] using SAR=64/45
[libx264 @ 0000000002b10760] using cpu capabilities: MMX2 SSE2Fast SSSE3
SSE4.2 AVX
[libx264 @ 0000000002b10760] profile Constrained Baseline, level 3.0
[libx264 @ 0000000002b10760] 264 - core 148 r2762 90a61ec - H.264/MPEG-4
AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html -
options: cabac=0 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7
psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1
8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12
lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0
bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250
keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1
bitrate=750 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40
aq=1:1.00
Output #0, mp4, to 'starwarssub2 64k mono.mp4':
Metadata:
encoder : Lavf57.70.100
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p,
720x576 [SAR 64:45 DAR 16:9], q=-1--1, 750 kb/s, 25 fps, 12800 tbn, 25 tbc
Metadata:
encoder : Lavc57.88.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/750000 buffer size: 0 vbv_delay: -1
Stream #0:1: Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, mono,
fltp, 64 kb/s
Metadata:
encoder : Lavc57.88.100 aac
[mp4 @ 000000000033b5a0] Non-monotonous DTS in output stream 0:1;
previous: 2560, current: 2048; changing to 2561. This may result in
incorrect timestamps in the output file.
frame= 135 fps=0.0 q=27.0 size= 306kB time=00:00:05.09 bitrate=
492.3kbits/s dup=6 drop=0 speed=10.2x
frame= 263 fps=262 q=27.0 size= 804kB time=00:00:10.28 bitrate=
640.8kbits/s dup=6 drop=0 speed=10.3x
frame= 386 fps=256 q=29.0 size= 1412kB time=00:00:15.21 bitrate=
760.6kbits/s dup=6 drop=0 speed=10.1x
frame= 513 fps=255 q=28.0 size= 1883kB time=00:00:20.30 bitrate=
759.7kbits/s dup=6 drop=0 speed=10.1x
frame= 634 fps=253 q=29.0 size= 2400kB time=00:00:25.10 bitrate=
783.2kbits/s dup=6 drop=0 speed= 10x
frame= 777 fps=258 q=28.0 size= 2894kB time=00:00:30.82 bitrate=
769.0kbits/s dup=6 drop=0 speed=10.2x
frame= 887 fps=253 q=29.0 size= 3379kB time=00:00:35.22 bitrate=
785.8kbits/s dup=6 drop=0 speed= 10x
[mpeg2video @ 00000000025d7c40] ac-tex damaged at 9 31
[mpeg2video @ 00000000025d7c40] Warning MVs not available
[mpeg2video @ 00000000025d7c40] concealing 225 DC, 225 AC, 225 MV errors
in P frame
[ac3 @ 00000000025d85e0] incomplete frame
frame= 959 fps=238 q=-1.0 Lsize= 3939kB time=00:00:38.32 bitrate=
842.2kbits/s dup=6 drop=0 speed=9.51x
video:3616kB audio:301kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.571200%
[libx264 @ 0000000002b10760] frame I:8 Avg QP:19.11 size: 37600
[libx264 @ 0000000002b10760] frame P:951 Avg QP:22.40 size: 3577
[libx264 @ 0000000002b10760] mb I I16..4: 29.4% 0.0% 70.6%
[libx264 @ 0000000002b10760] mb P I16..4: 0.7% 0.0% 0.2% P16..4:
27.7% 8.7% 3.3% 0.0% 0.0% skip:59.5%
[libx264 @ 0000000002b10760] final ratefactor: 22.86
[libx264 @ 0000000002b10760] coded y,uvDC,uvAC intra: 43.7% 53.4% 30.7%
inter: 10.9% 13.5% 0.2%
[libx264 @ 0000000002b10760] i16 v,h,dc,p: 86% 6% 4% 4%
[libx264 @ 0000000002b10760] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 18% 14%
6% 7% 8% 7% 7% 6%
[libx264 @ 0000000002b10760] i8c dc,h,v,p: 57% 26% 14% 3%
[libx264 @ 0000000002b10760] ref P L0: 80.5% 12.8% 6.7%
[libx264 @ 0000000002b10760] kb/s:772.08
[aac @ 0000000002b115c0] Qavg: 187.389
}}}
In this case, the Bitrate is 64.7 kbps...
--
Ticket URL: <https://trac.ffmpeg.org/ticket/6330#comment:2>
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