At Tue, 27 Apr 2004 20:36:29 +0200, Juan Carlos Granda wrote: > > [1 <text/plain; iso-8859-1 (quoted-printable)>] > > [2 <text/html; iso-8859-1 (quoted-printable)>] > Hi, > > I'm developing a Multi-thread app for capturing audio+video and i have a few > questions. The app is based on 3 threads: > > - 1 thread for capturing audio using ALSA lib. > - 1 thread for capturing video using V4L2. > - 1 thread for saving audio+video into an AVI file. > > Both of capturing threads store captured data into a queue and the last thread picks > the data and sync A/V. > > I start audio capturing and then the video. So, i need to known the point of the > stream of audio the video begins. > I'm readings frames by period size times. My prob is how to get valid ALSA timestamps > to eliminate the previous frames of the period the video starts. I've tried > snd_pcm_status_get_trigger_tstamp but it returns the same timestamp for a long period > of time (13 secs) (is it related to the period or buffer time?). I've tried > snd_pcm_status_get_tstamp too but i obtain a delay of several microseconds from the > period time (50 - 100 more or less) (is it because the clock resolution?).
the alsa-driver can put timestamp at each period update. set SND_TSTAMP_MMAP in snd_pcm_sw_params_set_tstamp_mode(). Takashi ------------------------------------------------------- This SF.Net email is sponsored by: Oracle 10g Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE. http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
