Lines Matching +full:playback +full:- +full:only
7 - Trigger_tstamp is the system time snapshot taken when the .trigger
10 capabilities or conversely may only be able to provide a correct
11 estimate with a delay. In the latter two cases, the low-level driver
17 - tstamp is the current system timestamp updated during the last
19 The difference (tstamp - trigger_tstamp) defines the elapsed time.
29 - ``avail`` reports how much can be written in the ring buffer
30 - ``delay`` reports the time it will take to hear a new sample after all
43 ascii-art, this could be represented as follows (for the playback
47 --------------------------------------------------------------> time
53 |< codec delay >|<--hw delay-->|<queued samples>|<---avail->|
54 |<----------------- delay---------------------->| |
55 |<----ring buffer length---->|
58 The analog time is taken at the last stage of the playback, as close
67 The DMA time is measured using counters - typically the least reliable
76 accuracy. It can also request the delay-to-analog be included in the
84 in hardware/low-level driver, the type is overridden as DEFAULT and the
88 provide timestamp selection, with a zero-valued COMPAT timestamp type
89 the results will default to the HDAudio wall clock for playback
92 The audio timestamp accuracy can be returned to user-space, so that
95 - for dma time (default), the granularity of the transfers can be
100 - the link time can be used to track long-term drifts between audio
101 and system time using the (tstamp-trigger_tstamp)/audio_tstamp
102 ratio, the precision helps define how much smoothing/low-pass
105 different streams - but may require the wallclock to be always
106 running and not wrap-around during idle periods). If supported in
110 - including the delay in the audio timestamp may
111 counter-intuitively not increase the precision of timestamps, e.g. if a
112 codec includes variable-latency DSP processing or a chain of
115 The accuracy is reported in nanosecond units (using an unsigned 32-bit
121 the ``STATUS`` ioctl, the parameters are read-only and do not allow for
124 with read/write parameters. ALSA-lib will be modified to make use of
127 The ALSA API only allows for a single audio timestamp to be reported
136 In some hardware-specific configuration, the system timestamp is
137 latched by a low-level audio subsystem, and the information provided
151 $ ./audio_time -p --ts_type=1
152 playback: systime: 341121338 nsec, audio time 342000000 nsec, systime delta -878662
153 playback: systime: 426236663 nsec, audio time 427187500 nsec, systime delta -950837
154 playback: systime: 597080580 nsec, audio time 598000000 nsec, systime delta -919420
155 playback: systime: 682059782 nsec, audio time 683020833 nsec, systime delta -961051
156 playback: systime: 852896415 nsec, audio time 853854166 nsec, systime delta -957751
157 playback: systime: 937903344 nsec, audio time 938854166 nsec, systime delta -950822
162 $ ./audio_time -p --ts_type=1 -d
163 playback: systime: 341053347 nsec, audio time 341062500 nsec, systime delta -9153
164 playback: systime: 426072447 nsec, audio time 426062500 nsec, systime delta 9947
165 playback: systime: 596899518 nsec, audio time 596895833 nsec, systime delta 3685
166 playback: systime: 681915317 nsec, audio time 681916666 nsec, systime delta -1349
167 playback: systime: 852741306 nsec, audio time 852750000 nsec, systime delta -8694
172 $ ./audio_time -p --ts_type=2 -d
173 playback: systime: 341060004 nsec, audio time 341062791 nsec, systime delta -2787
174 playback: systime: 426242074 nsec, audio time 426244875 nsec, systime delta -2801
175 playback: systime: 597080992 nsec, audio time 597084583 nsec, systime delta -3591
176 playback: systime: 682084512 nsec, audio time 682088291 nsec, systime delta -3779
177 playback: systime: 852936229 nsec, audio time 852940916 nsec, systime delta -4687
178 playback: systime: 938107562 nsec, audio time 938112708 nsec, systime delta -5146
181 ahead of the actual playback time (as a side time this sort of
183 DMA-link delay in example 2 helps remove the hardware buffering but
197 $ ./audio_time -p -Dhw:1 -t1
198 playback: systime: 120174019 nsec, audio time 125000000 nsec, systime delta -4825981
199 playback: systime: 245041136 nsec, audio time 250000000 nsec, systime delta -4958864
200 playback: systime: 370106088 nsec, audio time 375000000 nsec, systime delta -4893912
201 playback: systime: 495040065 nsec, audio time 500000000 nsec, systime delta -4959935
202 playback: systime: 620038179 nsec, audio time 625000000 nsec, systime delta -4961821
203 playback: systime: 745087741 nsec, audio time 750000000 nsec, systime delta -4912259
204 playback: systime: 870037336 nsec, audio time 875000000 nsec, systime delta -4962664
209 $ ./audio_time -p -Dhw:1 -t1 -d
210 playback: systime: 120190520 nsec, audio time 120000000 nsec, systime delta 190520
211 playback: systime: 245036740 nsec, audio time 244000000 nsec, systime delta 1036740
212 playback: systime: 370034081 nsec, audio time 369000000 nsec, systime delta 1034081
213 playback: systime: 495159907 nsec, audio time 494000000 nsec, systime delta 1159907
214 playback: systime: 620098824 nsec, audio time 619000000 nsec, systime delta 1098824
215 playback: systime: 745031847 nsec, audio time 744000000 nsec, systime delta 1031847