[mythtv] [PATCH] ALSA threaded/buffered rewrite

David George david at thegeorges.us
Sat Jul 24 14:59:29 EDT 2004


Kevin Kuphal wrote:

> At the suggestion on the list here a little while back, I took the 
> time to basically duplicate the OSS audio code (threading, buffers, 
> etc) into the ALSA functions.  I've tested this on my system and I can 
> playback with my audio device as ALSA:spdif with no studdering or 
> jumping but the audio is not in sync with the video and I was hoping 
> someone here that understands such things more than I could take a 
> look at it.  I'm no ALSA expert nor am I an audio expert.

I should have asked before.  What sound card are you using?  Maybe it is 
something incompatible with mine.

Also, when you enable audio logging and uncomment the line from 
getSpaceOnSoundCard what do you get?  I have 2004-07-24 14:50:46 
getSpaceOnSoundcard : 32 0 0 128.  Next I get waiting for space to write 
4096 zeros on soundcard which has 128 bytes free.

Here is the output from lspci -v on this machine:

00:1f.5 Multimedia audio controller: Intel Corp. 82801DB (ICH4) AC'97 
Audio Controller (rev 02)
        Subsystem: Asustek Computer, Inc.: Unknown device 8095
        Flags: bus master, medium devsel, latency 0, IRQ 11
        I/O ports at 7800
        I/O ports at 7400 [size=64]
        Memory at ca800000 (32-bit, non-prefetchable) [size=512]
        Memory at ca000000 (32-bit, non-prefetchable) [size=256]
        Capabilities: [50] Power Management version 2

mplayer and aplay work fine, it is just Myth that has no audio.

I also have an Abit motherboard with the same issue

00:1f.5 Multimedia audio controller: Intel Corp. 82801DB (ICH4) AC'97 
Audio Controller (rev 02)
        Subsystem: ABIT Computer Corp.: Unknown device 1006
        Flags: bus master, medium devsel, latency 0, IRQ 5
        I/O ports at e000
        I/O ports at e400 [size=64]
        Memory at e0001000 (32-bit, non-prefetchable) [size=512]
        Memory at e0002000 (32-bit, non-prefetchable) [size=256]
        Capabilities: [50] Power Management version 2

I also tried an SBLive in the Abit computer and have the same problem.

02:02.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 08)
        Subsystem: Creative Labs CT4760 SBLive!
        Flags: bus master, medium devsel, latency 64, IRQ 5
        I/O ports at 8400
        Capabilities: [dc] Power Management version 1

I am still looking into it.  If you could give me the lspci -v output 
for your audio and your kernel and alsa versions, and the output of 
getSpaceOnSoundCard it may help me track down what my problem is.

Thanks,
David


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