Lines Matching +full:fixed +full:- +full:rate

29 to the device-specific manual pages for a complete description of each hardware
44 .Ss "Multi-Stream Codecs"
45 The audio mixer supports multi-stream Codecs.
47 that provide sample rate conversion, hardware mixing, and other features.
58 monaural audio recorded in \(*m-Law format (pronounced
59 .Em mew-law )
61 audio format (stereo 16-bit linear
73 Sample Rate, Encoding, Precision, and Channels.
74 Refer to the device-specific
80 .Ss "Sample Rate"
81 Sample rate is a number that represents the sampling frequency (in samples per
85 rate for both play and record.
87 require compute-intensive low pass filtering.
88 The result is that high sample rate audio streams are not degraded by filtering.
90 Sample rate conversion can be a compute-intensive operation, depending on the
91 number of channels and a device's sample rate.
99 Applications can greatly reduce the impact of sample rate conversion by
100 carefully picking the sample rate.
102 sample rate the device supports.
103 An application can also do its own sample rate
112 \(*m-Law
117 A-Law encoding is also part of
120 A-Law and \(*m-Law audio data are sampled at
121 a rate of 8000 samples per second with 12-bit precision, with the data
122 compressed to 8-bit samples.
132 For instance, \(*m-Law and A-Law data are stored with 8-bit precision.
134 data may be stored at various precisions, though 16-bit is the most common.
138 For example, a sample frame of stereo 16-bit
140 data consists of two 16-bit samples,
149 .Bl -column "Signed Linear PCM" "Precision" "Mono or Stereo" -offset 2n
151 .It "Signed Linear PCM" Ta "32-bit" Ta "Mono or Stereo"
152 .It "Signed Linear PCM" Ta "16-bit" Ta "Mono or Stereo"
153 .It "Signed Linear PCM" Ta "8-bit" Ta "Mono or Stereo"
154 .It "\(*m-Law" Ta "8-bit" Ta "Mono or Stereo"
155 .It "A-Law" Ta "8-bit" Ta "Mono or Stereo"
158 The audio mixer converts all audio streams to 24-bit Linear PCM before mixing.
164 Note that the mixer discards the low order 8 bits of 32-bit Signed Linear PCM
167 fit into 32-bits when mixing multiple streams together.)
168 Hence, the maximum effective precision is 24-bits.
205 .Bl -bullet -offset indent
214 argument, then -1 is immediately returned, with
226 the process, in which case a -1 is returned with
235 format of the audio channel to the default state of 8-bit, 8Khz, mono \(*m-Law
255 The device may alternatively be set to a non-blocking mode, in which case
265 processes that do not record audio data should open the device write-only
294 it will accumulate at 8000 bytes per second for 8-bit, 8 KHz, mono, \(*m-Law data.
295 If the device is configured for 16-bit linear or higher sample rates, it will
298 up with this data rate, the
318 The device may alternatively be set to a non-blocking mode, in which case
333 asynchronous notification of output completion by writing a zero-length buffer
334 (end-of-file record) to the output stream.
364 buffers at a default rate of at
365 least 8000 bytes per second for \(*m-Law, A-Law or 8-bit PCM data (faster for
366 16-bit linear data or higher sampling rates).
390 enable non-blocking
397 .Ss "Audio Control Pseudo-Device"
404 pseudo-device is provided for this purpose.
427 Applications that open the audio control pseudo-device may request asynchronous
437 .Bl -bullet -offset indent
445 An end-of-file record (zero-length buffer) has been processed on output.
470 .Bd -literal -offset 2n
500      uchar_t pause;  /* non-zero if paused, zero to resume */
501      uchar_t error;  /* non-zero if overflow/underflow */
502      uchar_t waiting; /* non-zero if a process wants access */
506       * The following values are read-only device state
509       uchar_t open;   /* non-zero if open access granted */
510       uchar_t active; /* non-zero if I/O active */
524     uchar_toutput_muted; /* non-zero if output muted */
533 #define AUDIO_ENCODING_ULAW (1) /* u-Law encoding */
534 #define AUDIO_ENCODING_ALAW (2) /* A-Law encoding */
558 #define AUDIO_SPEAKER   (0x01) /* built-in speaker */
570 #define AUDIO_CD       (0x04) /* on-board CD inputs */
581 /* multi-stream Codec */
608 Audio output may also be temporarily muted by setting a non-zero value in the
637 fields are fixed to
697 field increments whenever a zero-length output buffer is synchronously processed.
712 Refer to the audio device-specific manual page for more details.
717 rate.
757 audio device-specific manual pages for a list of supported data format
799 .Bl -tag -width "AUDIO_GETINFO"
828 will be a device-specific string identifying the properties of the audio stream
830 Refer to the audio device-specific manual
878 treated as read-only when
892 fields treated as read-only for
916 For instance, the following code switches the output port from the built-in
918 .Bd -literal -offset 2n
933 .Bl -tag -width "/usr/share/audio/samples"
951 .Bl -tag -width "EINTR"
969 .Bl -tag -width "EINVAL"