[FFmpeg-trac] #2686(avcodec:open): Native AAC encoder collapses at high bitrates on some samples
FFmpeg
trac at avcodec.org
Thu Jul 25 18:21:14 CEST 2013
#2686: Native AAC encoder collapses at high bitrates on some samples
-------------------------------------+-------------------------------------
Reporter: Kamedo2 | Owner:
Type: defect | Status: open
Priority: normal | Component: avcodec
Version: git-master | Resolution:
Keywords: aac | Blocked By:
regression | Reproduced by developer: 1
Blocking: |
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Comment (by Kamedo2):
I inserted
{{{
av_log(NULL, AV_LOG_DEBUG, "\n cutoff=%d, lambda=%f, frame_bit_rate=%d,
bandwidth=%d\n",cutoff,lambda,frame_bit_rate,bandwidth);
}}}
in aaccoder.c twoloop line 795, and found cutoff differs between different
frames. I used -q:a 0.4, stereo 44.1kHz. I assume <99 cutoffs are the
short blocks and 500< cutoffs are the long tonal blocks. The cutoff varies
throughout the same music. 11.7k~13.6k for the short blocks, 11.5k~13.2k
for the long blocks. (Calculated from the 25 raw examples below)
{{{
cutoff=77, lambda=47.000000, frame_bit_rate=46034, bandwidth=14508
cutoff=614, lambda=47.000000, frame_bit_rate=45648, bandwidth=14412
cutoff=76, lambda=47.000000, frame_bit_rate=45648, bandwidth=14412
cutoff=612, lambda=47.000000, frame_bit_rate=45417, bandwidth=14354
cutoff=76, lambda=47.000000, frame_bit_rate=45417, bandwidth=14354
cutoff=532, lambda=47.000000, frame_bit_rate=37937, bandwidth=12484
Last message repeated 1 times
cutoff=538, lambda=47.000000, frame_bit_rate=38477, bandwidth=12619
Last message repeated 1 times
size= 242kB time=00:00:15.80 bitrate= 125.2kbits/s
cutoff=68, lambda=47.000000, frame_bit_rate=39017, bandwidth=12754
cutoff=544, lambda=47.000000, frame_bit_rate=39017, bandwidth=12754
cutoff=548, lambda=47.000000, frame_bit_rate=39402, bandwidth=12850
Last message repeated 1 times
cutoff=551, lambda=47.000000, frame_bit_rate=39711, bandwidth=12927
Last message repeated 1 times
cutoff=554, lambda=47.000000, frame_bit_rate=39942, bandwidth=12985
Last message repeated 1 times
cutoff=69, lambda=47.000000, frame_bit_rate=40173, bandwidth=13043
cutoff=556, lambda=47.000000, frame_bit_rate=40173, bandwidth=13043
cutoff=69, lambda=47.000000, frame_bit_rate=40405, bandwidth=13101
cutoff=558, lambda=47.000000, frame_bit_rate=40405, bandwidth=13101
cutoff=561, lambda=47.000000, frame_bit_rate=40636, bandwidth=13159
Last message repeated 1 times
cutoff=562, lambda=47.000000, frame_bit_rate=40713, bandwidth=13178
Last message repeated 1 times
cutoff=71, lambda=47.000000, frame_bit_rate=41870, bandwidth=13467
cutoff=574, lambda=47.000000, frame_bit_rate=41870, bandwidth=13467
cutoff=79, lambda=47.000000, frame_bit_rate=47653, bandwidth=14913
Last message repeated 1 times
cutoff=78, lambda=47.000000, frame_bit_rate=46651, bandwidth=14662
Last message repeated 1 times
cutoff=76, lambda=47.000000, frame_bit_rate=45031, bandwidth=14257
Last message repeated 1 times
[output stream 0:0 @ 04adab60] EOF on sink link output stream 0:0:default.
No more output streams to write to, finishing.
cutoff=75, lambda=47.000000, frame_bit_rate=44337, bandwidth=14084
Last message repeated 1 times
cutoff=68, lambda=47.000000, frame_bit_rate=39711, bandwidth=12927
Last message repeated 1 times
[aac @ 04aaf580] Trying to remove 504 more samples than there are in the
queue
size= 253kB time=00:00:16.10 bitrate= 128.9kbits/s
video:0kB audio:250kB subtitle:0 global headers:0kB muxing overhead
1.475195%
755 frames successfully decoded, 0 decoding errors
[AVIOContext @ 04ad0440] Statistics: 30 seeks, 779 writeouts
[AVIOContext @ 04d6f8a0] Statistics: 3123324 bytes read, 2 seeks
}}}
{{{
ffmpeg54890g.exe -v 9 -loglevel 99 -i ffmpeg_aacvbr_pulse2.wav -c:a aac
-strict experimental -q:a 0.4 ffmpeg_aacvbr_pulse2.mp4
}}}
I tried to automate it by batch script, including preserving the av_log
output but somehow it freezes.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2686#comment:106>
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