On 04/04/2014 08:54 AM, julien@xxxxxxxxxxxx wrote: > On 04/03/2014 11:16 AM, Daniel Mack wrote: >> ... 16bit, so things don't work for you in 192k/16bit, right? > > Well, it's not like I had experienced a lot with it, but the few times I > tried 16/192, I didn't hear the crackles that are very noticeable in > 24/192. Sure. I'm just trying to get an idea what causes the trouble. >> http://zonque.org/sine-192khz.wav (~22 MB) > I just tried to playback this file with your buffer size and I can > confirm there are issues in 16/192 too: with buffer-size=256, lots of > crackle s. Buffer needs to be raised to 384/512 to sound normal. Ok, that's different on my system, but still, it might depend on your USB host controller chipset, or other details. After all, it seems to be a matter of buffer sizes, not stream corruption or anything. > Yesterday I got my hands on more diverse 24/192 content to make more > experiments. I've come to the conclusion that the crackles that were > very noticeable with the patch mentioned upper in the thread are not > 100% absent without the patch, they are just very less frequent and > harder to notice, but are still there. The experiments I made yesterday > were using aplay, without specifying any buffer size, here's what aplay > -vD[..] gives playing some of this new content without specifying the > buffer size: Ok, so what would really help if you dumped the sizes for each prepared URB from data_ep_set_params() with and without the patch and see where the differences are, while keeping your userspace setup the same. > Seems to default to a much bigger buffer size. What's interesting that > if a smaller buffer (e.g: 512) is specified I'm really unable to spot > any crackle. Could it be a question of sweet spot that some apps have a > hard time finding? It certainly has to do with it, but the driver should be able to cope with settings that were working before the patch. Thanks for your investigations, Daniel ------------------------------------------------------------------------------ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
