On Wed, 11 Jul 2007, Steve Longerbeam wrote: > Last night I ran an experiment. I created a 16-bit stereo .wav file > with all left samples = 0x5555, and all right samples = 0xAAAA. I then > played the .wav using aplay, and just before trigger start in my driver > I searched the DMA buffer for the first occurrence of 0xAAAA. The right > samples didn't start until exactly half-way through the entire DMA buffer! Yes, it's the right non-interleaved behaviour. You can imagine this layout as separate "mono" ring buffers for each channels - see snd_pcm_lib_ioctl_channel_info() in pcm_lib.c . Driver might modify info->offset if required (see hdsp.c driver for example). Jaroslav ----- Jaroslav Kysela <perex@xxxxxxx> Linux Kernel Sound Maintainer ALSA Project, SUSE Labs _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
