[Ffmpeg-devel] Audio glitches

Robert Gomułka carramba
Mon Mar 20 19:10:18 CET 2006

audio from one of my files glitches. That means after some time starts 
distorting, sounds weird (not all the time). Video is playing fine.
How do I reproduce it:
1. Play file with either mplayer or ffplay
2. Wait about 20 seconds
3. Hear the distorsions

Workaround - switching audio codec in mplayer from ffmpeg to wma9dmo. It works 
fine, although it may also confirm problem in ffmpeg itself.

ffmpeg version used - Debian packages (nerim.net) from 20060318 (would test 
other versions if needed).

The file is located on http://klif-e.mos.net.au/videos/extr.wmv (9 MB) - I 
wanted to copy it to ftp (as written in bugreports page), however I couldn't 
find incoming directory.

Relevant (I guess) audio lines (mplayer):
ASF file format detected.
stream type: guid_audio_stream
stream concealment: guid_audio_conceal_interleave
type: 28 bytes,  stream: 8 bytes  ID: 1
unk1: 0  unk2: 23EFCD8
==> Found audio stream: 1
======= WAVE Format =======
Format Tag: 353 (0x161)
Channels: 2
Samplerate: 32000
avg byte/sec: 4000
Block align: 768
bits/sample: 16
cbSize: 10
Unknown extra header dump: [0] [88] [0] [0] [17] [0] [0] [1e] [0] [0]
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
dec_audio: Allocating 192000 + 65536 = 257536 bytes for output buffer.
FFmpeg's libavcodec audio codec
INFO: libavcodec init OK!
AUDIO: 32000 Hz, 2 ch, s16le, 32.0 kbit/3.12% (ratio: 4000->128000)
Selected audio codec: [ffwmav2] afm: ffmpeg (DivX audio v2 (FFmpeg))
Building audio filter chain for 32000Hz/2ch/s16le -> 0Hz/0ch/??...
[libaf] Adding filter dummy
[dummy] Was reinitialized: 32000Hz/2ch/s16le
[dummy] Was reinitialized: 32000Hz/2ch/s16le
alsa-init: requested format: 32000 Hz, 2 channels, 9
alsa-init: compiled for ALSA-1.0.10
alsa-init: setup for 1/2 channel(s)
alsa-init: 1 soundcard found, using: default
alsa-init: pcm opend in blocking mode
alsa-init: chunksize set to 1024
alsa-init: fragcount=16
alsa-init: got buffersize=65536
alsa-init: got period size 1024
alsa: 32000 Hz/2 channels/4 bpf/65536 bytes buffer/Signed 16 bit Little Endian
AO: [alsa] 32000Hz 2ch s16le (2 bytes per sample)
AO: Description: ALSA-0.9.x-1.x audio output
AO: Author: Alex Beregszaszi, Zsolt Barat <joy at streamminister.de>
AO: Comment: under developement
Building audio filter chain for 32000Hz/2ch/s16le -> 32000Hz/2ch/s16le...
[dummy] Was reinitialized: 32000Hz/2ch/s16le
[dummy] Was reinitialized: 32000Hz/2ch/s16le
Starting playback...

Best regards,

Profesjonalne nag?o?nienie koncert?w muzycznych, telewizyjnych program?w rozrywkowych itp..
Zapraszamy do odwiedzenia naszej strony www.audio-tech.com.pl 

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