13.09.2014 17:33, Raymond Yau wrote:
2014-9-13 下午6:43 於 "Alexander E. Patrakov" <patrakov@gmail.com mailto:patrakov@gmail.com> 寫道：
13.09.2014 14:57, Raymond Yau wrote:
On my desktop PC, on snd-hda-intel with analog outputs for S16LE
stereo, the granularity is 32 bytes (= 8 samples), and I get the
pointer
granularity of 64 bytes (=16 samples) over HDMI. The minimum
period size
is 32 samples in both cases.
Do you mean hda-Intel does not support arbritray period size
when you
say the granularity is 32 bytes ?
However the granularity of the emulated hda sound card inside any VM depend on the vm and the backend audio system and sound card
The precise meaning is defined here:
http://mailman.alsa-project.org/pipermail/alsa-devel/2014-May/076475.html
Do you mean the different hda controllers may have different
granularity ?
Yes. My two hda controllers have different granularity.
Do your two hda controllers have different Fifo size ?
If you mean the result of snd_pcm_hw_params_get_fifo_size(), then
both cards return 0. I call this function after snd_pcm_hw_params(), as recommended by the documentation.
Do your hda controllers OSDnFIFOS register match the granularity ?
I don't know. Please send a program or a kernel patch that prints this value (including units - samples or bytes), otherwise I won't be able to answer.