Dne 01. 04. 19 v 15:51 Giuliano Zannetti - ART S.p.A. napsal(a):
Hi,
I have the configuration in the asound.conf above.
my_plug - - > my_route - - > my_multi - - > slave0 (forward) - - > slave1 (loopback)
I open the plug my_plug in the block mode:
writtenFrames = snd_pcm_writei(handle, bufferToWrite, bufferToWriteSize);The issue I see is that there are several "writes" with 0 written frames. It seems like the snd_pcm_writei does not hold until data will be written. In general, 0 written frames sounds weird to me, because snd_pcm_writei should block itself if no space is available in the circular buffer right?
I have tried to fix the following method in pcm_multi.c, as Jaroslav Kysela suggests.
-static int snd_pcm_multi_may_wait_for_avail_min(snd_pcm_t *pcm, snd_pcm_uframes_t avail ATTRIBUTE_UNUSED) +static int snd_pcm_multi_may_wait_for_avail_min(snd_pcm_t *pcm, snd_pcm_uframes_t avail) { snd_pcm_multi_t *multi = pcm->private_data;
snd_pcm_t *slave = multi->slaves[multi->master_slave].pcm;return snd_pcm_may_wait_for_avail_min(slave, snd_pcm_mmap_avail(slave));
unsigned int i;for (i = 0; i < multi->slaves_count; ++i) {if (snd_pcm_may_wait_for_avail_min(multi->slaves[i].pcm, avail))return 1;}return 0;}
But unfortunately the issue has not been resolved.
Hi,
I did some debugging (it's pretty reproducible) and the real fixes are here:
https://git.alsa-project.org/?p=alsa-lib.git;a=commit;h=4694a6643dc09c5e4196... https://git.alsa-project.org/?p=alsa-lib.git;a=commit;h=c7fc3fdbe23e63757b0e... https://git.alsa-project.org/?p=alsa-lib.git;a=commit;h=369df322577034ea8729... https://git.alsa-project.org/?p=alsa-lib.git;a=commit;h=0bfad420efea328a5036...
Just get the latest alsa-lib and it should work correctly now. Let me know the result.
Thanks. Jaroslav