New submission from tripp <[EMAIL PROTECTED]>:
hi,
i've marked frequencies and bitrates of mp3 audio
with which ffmpeg when encoding to another format,
prints out invalid backstep errors.
mp3 files created with lame 3.97
from and upwards:
8kHz 64k
11.025kHz 96k
12kHz 96k
16kHz 128k
24kHz 128k *
44.1kHz 192k
48kHz 192k
with 22.05 kHz, i got no errors.
used 2 samples, with the one got no errors with 24 kHz,
with the other got these type:
overread, skip -7 enddists: -5 -5
overread, skip -5 enddists: -2 -2
overread, skip -8 enddists: -7 -7
overread, skip -7 enddists: -2 -2
overread, skip -7 enddists: -1 -1
overread, skip -7 enddists: -3 -3
overread, skip -7 enddists: -2 -2
with the rest this is the typical:
lame -b 96 --resample 11.025 aud48.wav 11.96.mp3
ffmpeg -i 11.96.mp3 -y out.wav
FFmpeg version SVN-r13799, Copyright (c) 2000-2008 Fabrice Bellard, et al.
configuration: --enable-memalign-hack --enable-postproc --enable-swscale --ena
ble-gpl --enable-liba52 --enable-libfaac --enable-libfaad --enable-libgsm --enab
le-libmp3lame --enable-libnut --enable-libvorbis --enable-libtheora --enable-lib
xvid --enable-libx264 --disable-ffserver --disable-ffplay --enable-avisynth --en
able-small --enable-pthreads --extra-ldflags=-static --extra-cflags=-mtune=penti
um4 -mfpmath=sse -msse -fno-strict-aliasing
libavutil version: 49.7.0
libavcodec version: 51.57.2
libavformat version: 52.16.0
libavdevice version: 52.0.0
built on Jun 18 2008 02:03:49, gcc: 4.3.1
invalid new backstep 613
Input #0, mp3, from '11.96.mp3':
Duration: 00:00:13.21, start: 0.000000, bitrate: 96 kb/s
Stream #0.0: Audio: mp3, 11025 Hz, mono, 96 kb/s
Output #0, wav, to 'out.wav':
Stream #0.0: Audio: pcm_s16le, 11025 Hz, mono, 176 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Press [q] to stop encoding
invalid new backstep 613
invalid new backstep 614
invalid new backstep 614
invalid new backstep 614
invalid new backstep 614
size= 286kB time=13.27 bitrate= 176.4kbits/s
video:0kB audio:286kB global headers:0kB muxing overhead 0.015037%
with most of the samples,
i didn't really notice anything audible,
but with 8Khz and 64k up, there is definite glitching.
i can upload say a 8.64.mp3 sample if needed,
but one should be able to easily create a sample of their
own in under a min.
ty
tripp
----------
messages: 2342
nosy: tripp
priority: normal
status: new
substatus: new
title: mp3 decoder / invalid backstep / 8kHz glitches
type: bug
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<https://roundup.mplayerhq.hu/roundup/ffmpeg/issue508>
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