Hi Mr. Iwai, Thanks for your replies. I have another question for you. After snd_pcm_start() is called, how long the first frame will be generated by the sound card? Does this duration vary in different nodes (support hardware+soundcard+OS are identical for all nodes)? If the duration is not a constant, do you have any idea what will be the largest jitter? This jitter matters so much for my location detection application. After the application starts, an user claps his/her hand. Then, the position of the user is calculated from the application. I have four VIA EPIA-M+Linux2.6 machines. A global time is setup among these four nodes. After the stream is started, the application detects a hand-clap sound and counts the number of frames from the stream start to the clap moment in each node. If I cannot have an accurate timestamp for the stream start, the application cannot caculate the clap sound timestamp accurately. Thanks, Sheng _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
