Red Hat Bugzilla – Bug 252942
5 channels are not supported in alsa
Last modified: 2007-11-30 17:07:46 EST
Description of problem:
I tested RHEL5.1-snapshot-1 kernel-2.6.18-37.el5-x86_64 on Intel Weybridge SDV
platform. The codec is SigmaTel STAC9274D.
When playing a 5 channels audio file, there is an error message "alsa-init: 5
channels are not supported". I checked
file /proc/asound/card0/pcm0p/sub0/hw_params and found only 2 channels are
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Play the audio file,
[root@localhost ~]# mplayer fivechannels.wav
MPlayer 1.0rc1-4.1.2 (C) 2000-2006 MPlayer Team
CPU: Intel(R) Core(TM)2 Duo CPU 6600 @ 2.40GHz (Family: 6, Model: 15,
CPUflags: MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE SSE2
Audio file file format detected.
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 44100 Hz, 5 ch, s16le, 3528.0 kbit/100.00% (ratio: 441000->441000)
Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
[AO OSS] audio_setup: Can't open audio device /dev/dsp: No such file or
alsa-init: 5 channels are not supported
AO: [alsa] 48000Hz 5ch s16le (2 bytes per sample)
Video: no video
A: 0.4 (00.3) of 0.7 (00.6) 1.3%
Exiting... (End of file)
2. At the same time, check hw_params,
[root@localhost ~]# cat /proc/asound/card0/pcm0p/sub0/hw_params
rate: 48000 (48000/1)
[root@localhost ~]# file fivechannels.wav
fivechannels.wav: RIFF (little-endian) data, WAVE audio, 5 channels 44100 Hz
Only 2 channels are open.
5 channels are open.
The attached file is a 5 channels WAVE file with only data in center channel.
So the expectation of playing this file is to get sound only in center
channel. From the current test result, there is no sound in center channel.
Created attachment 161633 [details]
A five channels WAVE audio file
*** This bug has been marked as a duplicate of 252943 ***