At Sun, 05 Jul 2009 09:03:23 -0300, Guilherme Longo wrote:
Hi all!
I came across a doubt regarding the the access mode between application and PCM device. It is a hardware parameter related property and there are 5 different types available:
SND_PCM_ACCESS_MMAP_INTERLEAVED SND_PCM_ACCESS_MMAP_NONINTERLEAVED SND_PCM_ACCESS_MMAP_COMPLEX SND_PCM_ACCESS_RW_INTERLEAVED SND_PCM_ACCESS_RW_NONINTERLEAVED
taking in account that these first 3 parameters has direct communication with the memory, that means a higher speed operation?
Yes. The others are using copy_from/to_user(), so there are slight overheads by explicit copying.
And the fact of the interleaved has all the samples mixed together , makes any difference in performance in comparison to the noninterleaved that has samples stored on different buffers?
No. It's just a difference of what format the hardware supports.
Takashi