[RFT] Major snd_hda rewrite
Alexander Motin
mav at FreeBSD.org
Tue Jan 24 22:33:52 UTC 2012
On 01/25/12 00:13, Mickaël Maillot wrote:
> 2012/1/24 Alexander Motin <mav at freebsd.org <mailto:mav at freebsd.org>>
> Here is it: http://people.freebsd.org/~__mav/hda.HBR.patch
> <http://people.freebsd.org/~mav/hda.HBR.patch>
> It should activate HBR mode if you try to play stream with AC3
> format and 8 channels (>6Mbps).
>
> no change with the patch because when i SNDCTL_DSP_SETFMT to AFMT_AC3,
> SNDCTL_DSP_CHANNELS always return 2 channels even if i
> set SNDCTL_DSP_SPEED to 192000.
> and i think it's why "if ((ch->fmt & AFMT_AC3) && (cchn == 8))" can't be
> true.
> i checked my /v/l/messages and saw PCMDIR_PLAY ....chan_count=0x01.
Number of channels should be set to 8 by application when it expects bit
rate above 6Mbps. Sample rate, as I've described, just give more fine
control. Increasing sample rate does not automatically increase
channels. They are orthogonal:
Rate 48 96 192 48 96 192
Channels 2 2 2 8 8 8
----------------------------------------------------------
Mbps 1.5 3 6 12 24 49
What I've forgot is to allow 8ch format. :) Add the patch below. Hope
sound(4) has no other limitations for it.
--- hdaa.c (revision 230511)
+++ hdaa.c (working copy)
@@ -4979,6 +4979,8 @@
}
if (HDA_PARAM_SUPP_STREAM_FORMATS_AC3(fmtcap)) {
ch->fmtlist[i++] = SND_FORMAT(AFMT_AC3, 2, 0);
+ if (channels >= 8)
+ ch->fmtlist[i++] = SND_FORMAT(AFMT_AC3,
8, 0);
}
ch->fmtlist[i] = 0;
i = 0;
But in your case I think it should be enough to just increase sample
rate to 96 or 192KHz.
--
Alexander Motin
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