Lines Matching +full:pcm +full:- +full:interface +full:- +full:rate

8 Tracepoints in ALSA PCM core
11 ALSA PCM core registers ``snd_pcm`` subsystem to kernel tracepoint system.
12 This subsystem includes two categories of tracepoints; for state of PCM buffer
13 and for processing of PCM hardware parameters. These tracepoints are available
18 Tracepoints for state of PCM buffer
19 ------------------------------------
24 Tracepoints for processing of PCM hardware parameters
25 -----------------------------------------------------
30 In a design of ALSA PCM core, data transmission is abstracted as PCM substream.
31 Applications manage PCM substream to maintain data transmission for PCM frames.
32 Before starting the data transmission, applications need to configure PCM
33 substream. In this procedure, PCM hardware parameters are decided by
34 interaction between applications and ALSA PCM core. Once decided, runtime of
35 the PCM substream keeps the parameters.
46         Configurable. ALSA PCM core and some drivers handle this flag to select
50         struct snd_mask and represent mask values. As of PCM protocol
53         - SNDRV_PCM_HW_PARAM_ACCESS
54         - SNDRV_PCM_HW_PARAM_FORMAT
55         - SNDRV_PCM_HW_PARAM_SUBFORMAT
59         PCM protocol v2.0.13, twelve types are defined.
61         - SNDRV_PCM_HW_PARAM_SAMPLE_BITS
62         - SNDRV_PCM_HW_PARAM_FRAME_BITS
63         - SNDRV_PCM_HW_PARAM_CHANNELS
64         - SNDRV_PCM_HW_PARAM_RATE
65         - SNDRV_PCM_HW_PARAM_PERIOD_TIME
66         - SNDRV_PCM_HW_PARAM_PERIOD_SIZE
67         - SNDRV_PCM_HW_PARAM_PERIOD_BYTES
68         - SNDRV_PCM_HW_PARAM_PERIODS
69         - SNDRV_PCM_HW_PARAM_BUFFER_TIME
70         - SNDRV_PCM_HW_PARAM_BUFFER_SIZE
71         - SNDRV_PCM_HW_PARAM_BUFFER_BYTES
72         - SNDRV_PCM_HW_PARAM_TICK_TIME
76         mask/interval parameter can be changed by ALSA PCM core. For
80         Read-only. After returning from ioctl(2), buffer in user space for
84         Read-only. This represents hardware/driver capabilities as bit flags
88         configure PCM substream.
90         Read-only. This value represents available bit width in MSB side of
91         a PCM sample. When a parameter of SNDRV_PCM_HW_PARAM_SAMPLE_BITS was
96         Read-only. This value represents numerator of sampling rate in fraction
102         Read-only. This value represents denominator of sampling rate in
108         Read-only. This value represents the size of FIFO in serial sound
109         interface of hardware. Basically, each driver can assigns a proper
113 ALSA PCM core handles buffer of struct snd_pcm_hw_params when
120 to compute the target parameter. ALSA PCM core registers some rules to the
138 mask/interval parameters. When ALSA PCM core changes them, ``hw_mask_param`` or
141 ALSA PCM core also has a pretty print format for each of the tracepoints. Below
155 The first three fields are common. They represent name of ALSA PCM character
157 field for rules of constraint consists of two sub-fields; index of applied rule
159 means that the parameter is changed by ALSA PCM core, regardless of the rules.