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| author | Daniel Mack <zonque@gmail.com> | 2013-04-17 00:01:36 +0800 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2013-04-18 10:02:33 +0200 |
| commit | ef7a4f979bd8201324b2bcd30277c14aba889f50 (patch) | |
| tree | 7235f0aa55aca6d7e7f2d67210c640e9ff4b9ec4 /sound/core | |
| parent | d5657ec9f4ad048873f2682d8945905b29938f57 (diff) | |
| download | linux-ef7a4f979bd8201324b2bcd30277c14aba889f50.tar.bz2 | |
ALSA: add DSD formats
This patch adds two formats for Direct Stream Digital (DSD), a
pulse-density encoding format which is described here:
https://en.wikipedia.org/wiki/Direct_Stream_Digital
DSD operates on 2.8, 5.6 or 11.2MHz sample rates and as a 1-bit
stream.
The two new types added by this patch describe streams that are capable
of handling DSD samples in DOP format as 8-bit or in 16-bit (or at a x8
or x16 data rate, respectively).
DSD itself specifies samples in *bit*, while DOP and ALSA handle them
as *bytes*. Hence, a factor of 8 or 16 has to be applied for the sample
rare configuration, according to the following table:
configured hardware
176.4KHz 352.8kHz 705.6KHz <---- sample rate
8-bit 2.8MHz 5.6MHz
16-bit 2.8Mhz 5.6MHz 11.2MHz
`-----------------------------'
actual DSD sample rates
Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/pcm.c | 2 | ||||
| -rw-r--r-- | sound/core/pcm_misc.c | 8 |
2 files changed, 10 insertions, 0 deletions
diff --git a/sound/core/pcm.c b/sound/core/pcm.c index 578327e2bc26..17f45e8aa89c 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -209,6 +209,8 @@ static char *snd_pcm_format_names[] = { FORMAT(G723_24_1B), FORMAT(G723_40), FORMAT(G723_40_1B), + FORMAT(DSD_U8), + FORMAT(DSD_U16_LE), }; const char *snd_pcm_format_name(snd_pcm_format_t format) diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c index b875b19f2d55..43f24cce3dec 100644 --- a/sound/core/pcm_misc.c +++ b/sound/core/pcm_misc.c @@ -140,6 +140,14 @@ static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = { .width = 5, .phys = 5, .le = -1, .signd = -1, .silence = {}, }, + [SNDRV_PCM_FORMAT_DSD_U8] = { + .width = 8, .phys = 8, .le = 1, .signd = 0, + .silence = {}, + }, + [SNDRV_PCM_FORMAT_DSD_U16_LE] = { + .width = 16, .phys = 16, .le = 1, .signd = 0, + .silence = {}, + }, /* FIXME: the following three formats are not defined properly yet */ [SNDRV_PCM_FORMAT_MPEG] = { .le = -1, .signd = -1, |