Lines Matching refs:channel

1 ALSA PCM channel-mapping API
8 The channel mapping API allows user to query the possible channel maps
9 and the current channel map, also optionally to modify the channel map
12 A channel map is an array of position for each PCM channel.
13 Typically, a stereo PCM stream has a channel map of
15 while a 4.0 surround PCM stream has a channel map of
18 The problem, so far, was that we had no standard channel map
19 explicitly, and applications had no way to know which channel
27 was no way to specify this because of lack of channel map
28 specification.  These are the main motivations for the new channel
35 Actually, "the channel mapping API" doesn't introduce anything new in
40 providing the channel mapping information and configuration.  This
51 allow user to change the channel map dynamically.
55 The TLV operation gives the list of available channel
56 maps.  A list item of a channel map is usually a TLV of
59 bytes (not the numbers) of channel values, and the rest are the
60 position value for each channel.
64 The _FIXED type is for a channel map with the fixed channel position
65 while the latter two are for flexible channel positions.  _VAR type is
66 for a channel map where all channels are freely swappable and _PAIRED
68 have {FL/FR/RL/RR} channel map, _PAIRED type would allow you to swap
74 The available channel position values are defined in sound/asound.h,
77 /* channel positions */
82 	/* this follows the alsa-lib mixer channel value + 3 */
112 When a PCM stream can provide more than one channel map, you can
113 provide multiple channel maps in a TLV container type.  The TLV data
121 The channel position is provided in LSB 16bits.  The upper bits are
128 SNDRV_CHMAP_PHASE_INVERSE indicates the channel is phase inverted,
132 When SNDRV_CHMAP_DRIVER_SPEC is set, all the channel position values
137 The control read operation is for providing the current channel map of
139 containing the position of each channel.
141 When this is performed before the number of the channel is specified
148 change the channel configuration on the fly, such as HDMI.  User needs
149 to pass an integer value containing the valid channel positions for