James Courtier-Dutton <[EMAIL PROTECTED]> writes: > Juan Carlos Granda wrote: >> That's my app does: >> 1.- Open the device for capture >> 2.- Set the access mode SND_PCM_ACCESS_RW_INTERLEAVED >> 3.- Set format 16 bits (SND_PCM_FORMAT_S16_LE) >> 4.- Set channels 2 (stereo) >> 5.- Set buffer time near 1 second >> 6.- Set period time near 0.1 seconds >> 7.- Copy the hardware params to alsa >> 8.- Set start threshold (0x7fffffffff -> Explicit start) >> 9.- Set transfer align 1 >> 10.- Copy the software params to alsa >> read loop: >> - Read 'period size' frames (snd_pcm_readi) >> How can i get the timestamp of the first frame read? If i use >> snd_pcm_status_get_trigger_tstamp i obtain the same timestamp all the times. >> If i use snd_pcm_status_get_tstamp i obtain the "now" time. Is there any way >> to get the timestamp of every period. >> Thanks >> > > I help develope xinehq.de. > We have needed to do audio, video sync, but we don't need any audio > timestamps using the get_trigger_tstamp etc. > We just use the snd_pcm_delay() call. > > Take an example. > Sample rate 10000 Samples a second (10000 just to make things easy to > explain.) > > We call snd_pcm_delay() and it returns 4000. > 4000 samples at a sample rate of 10000 = 400ms. > If we now write some samples to the sound device, we know that they > will arrive at the speakers in 400ms time.
The OP was recording. -- Måns Rullgård [EMAIL PROTECTED] ------------------------------------------------------- This SF.Net email is sponsored by Sleepycat Software Learn developer strategies Cisco, Motorola, Ericsson & Lucent use to deliver higher performing products faster, at low TCO. http://www.sleepycat.com/telcomwpreg.php?From=osdnemail3 _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
