[alsa-devel] ALSA 1.0.25 broke AC3 passthrough?
Hi
Today, I installed 1.0.25 drivers and libraries... AC3 passthrough is completely broken.
My hardware: NVidia GT430, hdmi output Device used: hdmi:CARD=NVidia,DEV=0,AES0=6,AES1=0x82,AES2=0x00,AES3=0x01 on Ubuntu 10.04 LTS (but using manually built alsa)
It makes the application hangs or behaves incorrectly. All the time broken, no matter which app. Reverting back to 1.0.24 fixes the problem
I haven't delved much into it yet, MythTV (I am the audio developer) after opening the audio device in passthrough mode, trying to write audio on the pcm just hangs and result in an I/O error after a little while snd_pcm_writei returns an error (not immediately) snd_pcm_state(pcm_handle) returns 3, snd_strerror(err) returns "Input/output error"
mplayer just hangs...
nothing obvious in the logs, audio device opens okay, i can't say I notice much difference in opening the device, allocating fragment and the lot.
Anyone else has seen this?
Jean-Yves
On 02/06/2012 04:38 AM, Jean-Yves Avenard wrote:
Today, I installed 1.0.25 drivers and libraries... AC3 passthrough is completely broken.
My hardware: NVidia GT430, hdmi output Device used: hdmi:CARD=NVidia,DEV=0,AES0=6,AES1=0x82,AES2=0x00,AES3=0x01 on Ubuntu 10.04 LTS (but using manually built alsa)
Are you able to regress this to a smaller window? I did do some rework a while back on the HDA driver to support newer GeForce GPUs' audio HW better, and this potentially had impact on bitstream pass-through, although it seemed to work at the time. Commits were:
384a48d ALSA: hda: HDMI: Support codecs with fewer cvts than pins 2def817 ALSA: hda: hdmi_eld_update_pcm_info: update a stream in place 3aaf898 ALSA: hda: Separate generic and non-generic implementations 74b654c ALSA: hda: Virtualize SPDIF out controls 7c93597 ALSA: hda: Allow multple SPDIF controls per codec
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Hi
On 7 February 2012 16:46, Stephen Warren swarren@nvidia.com wrote:
Are you able to regress this to a smaller window? I did do some rework a while back on the HDA driver to support newer GeForce GPUs' audio HW better, and this potentially had impact on bitstream pass-through, although it seemed to work at the time. Commits were:
I'm not sure what you mean by regress to a smaller window.
I use a quite "oldish" version of nvidia drivers: 260.19.36 (though same issue with latest 290.10).
At least one other mythtv user has reported the same problem with 1.0.25, not sure what his video/audio card is ...
384a48d ALSA: hda: HDMI: Support codecs with fewer cvts than pins 2def817 ALSA: hda: hdmi_eld_update_pcm_info: update a stream in place 3aaf898 ALSA: hda: Separate generic and non-generic implementations 74b654c ALSA: hda: Virtualize SPDIF out controls 7c93597 ALSA: hda: Allow multple SPDIF controls per codec
Do you want me to compile alsa back to those release and see if anything makes any difference?
Can certainly do so...
Jean-Yves
On 02/09/2012 03:01 AM, Jean-Yves Avenard wrote:
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Hi
On 7 February 2012 16:46, Stephen Warren swarren@nvidia.com wrote:
Are you able to regress this to a smaller window? I did do some rework a while back on the HDA driver to support newer GeForce GPUs' audio HW better, and this potentially had impact on bitstream pass-through, although it seemed to work at the time. Commits were:
I'm not sure what you mean by regress to a smaller window.
You'd mentioned that this problem was present in ALSA 1.0.25, but wasn't in some earlier release. Potentially a lot changed between those two releases. It'd be nice if you could try compiling a number of intermediate versions of the ALSA driver to try and more precisely locate the change that caused the issue. "git bisect" on the ALSA driver repository might be useful here.
Hi
On 10 February 2012 15:09, Stephen Warren swarren@nvidia.com wrote:
You'd mentioned that this problem was present in ALSA 1.0.25, but wasn't in some earlier release. Potentially a lot changed between those two releases. It'd be nice if you could try compiling a number of intermediate versions of the ALSA driver to try and more precisely locate the change that caused the issue. "git bisect" on the ALSA driver repository might be useful here.
Ok...
This is interesting..
Compiling from git, using tag v1.0.25, the problem is there... Compiling master, it's not
However, the issue doesn't show with v1.0.25, when the ALSA hardware buffer is set to its default 64kB. If I set it to a higher value (echo 4096 | sudo tee /proc/asound/card1/pcm3p/sub0/prealloc) ; then it shows up.
so obviously the issue has been fixed between the time 1.0.25 was released, and now.
I will try to identify which change between 1.0.24 and 1.0.25 broke it however... Which would lead precisely to which change in master fixed it. So a 1.0.25.2 can be released soon fixing that problem..
JY
participants (2)
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Jean-Yves Avenard -
Stephen Warren