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authorDaniel Mack <zonque@gmail.com>2013-04-17 00:01:36 +0800
committerTakashi Iwai <tiwai@suse.de>2013-04-18 10:02:33 +0200
commitef7a4f979bd8201324b2bcd30277c14aba889f50 (patch)
tree7235f0aa55aca6d7e7f2d67210c640e9ff4b9ec4 /sound/core
parentd5657ec9f4ad048873f2682d8945905b29938f57 (diff)
downloadop-kernel-dev-ef7a4f979bd8201324b2bcd30277c14aba889f50.zip
op-kernel-dev-ef7a4f979bd8201324b2bcd30277c14aba889f50.tar.gz
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.c2
-rw-r--r--sound/core/pcm_misc.c8
2 files changed, 10 insertions, 0 deletions
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 578327e..17f45e8 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 b875b19..43f24cc 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,
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