On 8/23/07, Liam Girdwood <lg@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > On Wed, 2007-08-22 at 22:13 +0530, Pharaoh . wrote: > > Hi > > While testing the audio driver using aplay in blocking mode, a periodic > > murmur is observed, this increases with > > the audio volume and occurs even when there are no issues like xrun etc. > > > Aplay was used in normal read/write mode > > i.e. no mmap. The song can be heard properly i.e. with no noticable gaps > aur > > hisses but the clicks are audible. > > Clock domain mismatch issues cause periodic ticks that increase in > frequency with increasing sample rate. It's possible your clocking the > codec and controller in two different clock domains. i.e. I2S controller > (bitclk and frame) clocked from CPU and codec clocked from separate > crystal. > > It's best to make sure that only one clock is clocking both the codec > and digital audio interface. > > Liam > > I tried playing /dev/zero at the same sampling rate as a wav file, but /dev/zero played without any clicks i.e absolutely no sound heard, but while playing a wav file using same parameters clicks occur. I am thinking it is not about clocks mis-match, since I have checked it several times. I was thinking whether junk data is being processed at end of buffer size, but since /dev/zero plays well, I am ruling out that possibility also. What else could explain the latencies at buffer ending as shown in the log in previous mail. -Pharaoh. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
