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ALSA: Define more channel map positions
For following the standard, define more channel map positions and
shuffle the items a bit:
- As both PulseAudio and gstreamer define MONO channel position
explicitly, we should follow that, too. The mono streams point to
this channel position unless they are explicitly assigned to certain
channel positions.
- Top-front-* and Top-rear-* positions are added, carried from
PulseAudio's definitions.
- Move NA and MONO definitions at the top of table right after
UNKNOWN, since these are more abstract in comparison with other
practical positions.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
+23
-9
+10
-3
Documentation/sound/alsa/Channel-Mapping-API.txt
+10
-3
Documentation/sound/alsa/Channel-Mapping-API.txt
···
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/* channel positions */
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enum {
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-
/* this follows the alsa-lib mixer channel value + 1 */
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SNDRV_CHMAP_UNKNOWN = 0,
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+
SNDRV_CHMAP_NA, /* N/A, silent */
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+
SNDRV_CHMAP_MONO, /* mono stream */
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+
/* this follows the alsa-lib mixer channel value + 3 */
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SNDRV_CHMAP_FL, /* front left */
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SNDRV_CHMAP_FR, /* front right */
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SNDRV_CHMAP_RL, /* rear left */
···
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SNDRV_CHMAP_FCH, /* front center high */
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SNDRV_CHMAP_FRH, /* front right high */
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SNDRV_CHMAP_TC, /* top center */
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-
SNDRV_CHMAP_NA, /* N/A, silent */
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-
SNDRV_CHMAP_LAST = SNDRV_CHMAP_NA,
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+
SNDRV_CHMAP_TFL, /* top front left */
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+
SNDRV_CHMAP_TFR, /* top front right */
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+
SNDRV_CHMAP_TFC, /* top front center */
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+
SNDRV_CHMAP_TRL, /* top rear left */
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+
SNDRV_CHMAP_TRR, /* top rear right */
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+
SNDRV_CHMAP_TRC, /* top rear center */
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+
SNDRV_CHMAP_LAST = SNDRV_CHMAP_TRC,
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};
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When a PCM stream can provide more than one channel map, you can
+10
-3
include/sound/asound.h
+10
-3
include/sound/asound.h
···
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/* channel positions */
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enum {
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-
/* this follows the alsa-lib mixer channel value + 1 */
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SNDRV_CHMAP_UNKNOWN = 0,
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+
SNDRV_CHMAP_NA, /* N/A, silent */
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+
SNDRV_CHMAP_MONO, /* mono stream */
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+
/* this follows the alsa-lib mixer channel value + 3 */
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SNDRV_CHMAP_FL, /* front left */
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SNDRV_CHMAP_FR, /* front right */
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SNDRV_CHMAP_RL, /* rear left */
···
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SNDRV_CHMAP_FCH, /* front center high */
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SNDRV_CHMAP_FRH, /* front right high */
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498
SNDRV_CHMAP_TC, /* top center */
501
-
SNDRV_CHMAP_NA, /* N/A, silent */
502
-
SNDRV_CHMAP_LAST = SNDRV_CHMAP_NA,
499
+
SNDRV_CHMAP_TFL, /* top front left */
500
+
SNDRV_CHMAP_TFR, /* top front right */
501
+
SNDRV_CHMAP_TFC, /* top front center */
502
+
SNDRV_CHMAP_TRL, /* top rear left */
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+
SNDRV_CHMAP_TRR, /* top rear right */
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+
SNDRV_CHMAP_TRC, /* top rear center */
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+
SNDRV_CHMAP_LAST = SNDRV_CHMAP_TRC,
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};
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#define SNDRV_CHMAP_POSITION_MASK 0xffff
+3
-3
sound/pci/ctxfi/ctpcm.c
+3
-3
sound/pci/ctxfi/ctpcm.c
···
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static const struct snd_pcm_chmap_elem surround_map[] = {
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{ .channels = 1,
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-
.map = { SNDRV_CHMAP_UNKNOWN } },
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+
.map = { SNDRV_CHMAP_MONO } },
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{ .channels = 2,
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.map = { SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
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{ }
···
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static const struct snd_pcm_chmap_elem clfe_map[] = {
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{ .channels = 1,
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-
.map = { SNDRV_CHMAP_UNKNOWN } },
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+
.map = { SNDRV_CHMAP_MONO } },
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{ .channels = 2,
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.map = { SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
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{ }
···
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static const struct snd_pcm_chmap_elem side_map[] = {
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{ .channels = 1,
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-
.map = { SNDRV_CHMAP_UNKNOWN } },
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+
.map = { SNDRV_CHMAP_MONO } },
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{ .channels = 2,
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.map = { SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
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{ }