If I keep the difference between the playback and capture pointers at one period, no choppy audio occurs. If the difference is 0, 2 or 5 periods for example, choppy audio will always occur. Any ideas why? Gustavo da Silva Serra escreveu:> Is it possible to detect this situation with alsa API, i.e., at > application level?>> Thanks.>> Gustavo da Silva Serra escreveu:> >> I have discovered something else: I am display the current buffer >> pointer (capture pointer and buffer pointer), when choppy audio occurs >> the playback pointer is printed as a given value and, after, the capture >> pointer has the same value. For example, a normal situation would be:>>>> Playback pointer: 3000>> Capture pointer: 1000>> Playback pointer: 4000>> Capture pointer: 2000>> Playback pointer: 0000>> Capture pointer: 3000>>>> A choppy audio situation would be:>>>> Playback pointer: 3000>> Capture pointer: 3000>> Playback pointer: 4000>> Capture pointer: 4000>> Playback pointer: 0000>> Capture pointer: 0000>>>> The following situation is NOT choppy:>>>> Capture pointer: 3000>> Playback pointer: 3000>> Capture pointer: 4000>> Playback pointer: 4000>> Capture pointer: 0000>> Playback pointer: 0000>>>> Thanks any reply.>>>> Gustavo da Silva Serra escreveu:>> >> >>> I am tracing aloop execution and the choppy audio happens when an >>> application (capture or playback) opens the device while another one is >>> capturing or playing. It seems to me, I may be completely wrong, that >>> the problem could be a synchronization issue (a critical region with no >>> mutexes, for instance). I analysed the sound wave with Audacity while in >>> choppy audio condition and I realized that there are silent gaps, >>> miliseconds with no sound at all (as if some buffer pointer was lost, >>> for example).>>>>>> I haven't received any answer from you =(>>> What do you think that is happening?>>>>>> Thanks in advance.>>>>>> Gustavo da Silva Serra escreveu:>>> >>> >>> >>>> I have been trying for many weeks to solve this problem, but with no >>>> success. After updating to Alsa 1.0.17, which include changes to aloop, >>>> I still have choppy audio. I will try to summarize what happens:>>>>>>>> - I need to use aloop, if I change to a sound card all the problems are >>>> gone;>>>> - After some time of continuous play, applications start to reproduce >>>> choppy audio. Choppy audio doesn't happens all the time;>>>> - If I repeatedly start and stop my sound capture application choppy >>>> audio occur sooner;>>>> - Start/stop my application restores the sound quality (after some tryies);>>>> - This happens with ALSA applications (xine, vlc) and OSS emulated;>>>> - I have tryied many period_size and buffer_size in asound.conf, now I >>>> am using 960 for period and 3840 for buffer. As I decrease period size, >>>> the audio quality improves, but choppy audio still happens;>>>> - I test for overrun but no errors occur.>>>> - I am using block mode, interleaved, 44100, 16 bit, 2 channels>>>> - I am using dmix, dsnoop, removing them does not correct the audio>>>>>>>> These are some of the information I have, I don't know if is is enough. >>>> If necessary I can provide any other information.>>>> What do you suggest that I do? Are there any known issues or >>>> configuration requirements?>>>>>>>> Thanks in advance.>>>> _______________________________________________>>>> Alsa-devel mailing list>>>> Alsa-devel@xxxxxxxxxxxxxxxx>>>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel>>>>>>>> __________ NOD32 3191 (20080616) Information __________>>>>>>>> This message was checked by NOD32 antivirus system.>>>> http://www.eset.com>>>>>>>>>>>>>>>> >>>> >>>> >>>> >>> >>> >>> >> >> >>> -- Gustavo da Silva Serra gustavo.serra@xxxxxxxxxx———————————————————————————Tools & Technologies - T&T Engenheiros Associados Ltda.Projetos de SW & HW - Desenvolvendo soluções.Rua Riachuelo, 1098 Conj. 1204Centro - Porto Alegre - CEP 90010-272Fone DDR: (51)3220-3290Fone/Fax: (51)3220-3220 / 3220-3206http://www.tet.com.br/ tet@xxxxxxxxxx _______________________________________________Alsa-devel mailing listAlsa-devel@xxxxxxxxxxxxxxxxxxxx://mailman.alsa-project.org/mailman/listinfo/alsa-devel
