Bug 85809 – Background audio ticking noise introduced during V4L2 video/audio capture after upgrading to alsa-lib 1.0.8

• Product: Gentoo Linux
• Status: RESOLVED WORKSFORME

[Description Sam 2005-03-18 12:19:20 UTC]

After upgrading from alsa-lib 1.0.6 to 1.0.8 a background noise (ticking sound) was introduced during video capture from TV BT878 capture card. Downgrading alsa-lib to 1.0.8-rc1 or lower eliminates the noise. This issue seems to be related to Alsa capture rather than playback for the following reasons:

1. Line-In coming from my TV capture card in clean
2. Noise is very apparent when the captured file is played back in a standalone DVD player.
3. Video files previously captured with alsa-lib 1.0.6 played back cleanly under alsa-lib 1.0.8 . Only files captured under alsa-lib 1.0.8 contain the noise.

Possibly related to Bug #85049?? Different enough I felt it warranted a separate Bug report.

Reproducible: Always
Steps to Reproduce:
1. Capture divX/ac3 video/audio file using alsa-lib 1.0.8, BT878 capture card, and mencoder
2. Playback using standalone DVD player or mplayer
Actual Results:  
Audio contains background ticking noise during playback

Expected Results:  
Clean playback as with alsa-lib 1.0.6

mencoder set to access alsa directly (Not using OSS emulation)
capture @ 44.1 kHz or 48 kHz
using snd_ens1371 sound card module with Creative Ensoniq Audio PCI card

[Comment 1 Diego Elio Pettenò (RETIRED) 2005-07-15 04:18:13 UTC]

Can you try with alsa-* 1.0.9 and alsa-driver instead of in-kernel drives? 
This should be fixed in later versions. 
 

[Comment 2 Sam 2005-07-15 07:45:50 UTC]

(In reply to comment #1)
> Can you try with alsa-* 1.0.9 and alsa-driver instead of in-kernel drives? 
> This should be fixed in later versions. 

Recent upgrade to gentoo-sources-2.6.12-r4 solved the problem. alsa-* 1.0.8 now
works fine. Thanks for following up.

[Comment 3 Diego Elio Pettenò (RETIRED) 2005-07-15 08:03:50 UTC]

Considering fixed then.