Em 14-06-2011 09:48, Hans de Goede escreveu: > Hi, > > On 06/14/2011 04:01 AM, Mauro Carvalho Chehab wrote: >> Hi Devin, >> >> I've made a few fixes for your alsa_stream.c, used on tvtime. >> They are at: >> http://git.linuxtv.org/xawtv3.git >> >> >> In particular, those are the more interesting ones: >> >> commit a1bb5ade5c2b09d6d6d624d18025f9e2c4398495 >> alsa_stream: negotiate the frame rate >> >> Without this patch, one of my em28xx devices doesn't work. It uses >> 32 k rate, while the playback minimal rate is 44.1 k. >> I've changed the entire frame rate logic, to be more reliable, and to >> avoid needing to do frame rate conversion, if both capture and playback >> devices support the same rate. >> >> commit 8adb3d7442b22022b9ca897b0b914962adf41270 >> alsa_stream: Reduce CPU usage by putting the thread into blocking mode >> >> This is just an optimization. I can't see why are you using a non-block >> mode, as it works fine blocking. >> >> commit c67f7aeb86c1caceb7ab30439d169356ea5b1e72 >> alsa_stream.c: use mmap mode instead of the normal mode >> >> Instead of using the normal way, this patch implements mmap mode, and change >> it to be the default mode. This should also help to reduce CPU usage. >> > > hmm, does this include automatic fallback to read mode if mmap mode is not > available, mmap mode does not work with a number of devices (such as pulseaudio's > alsa plugin). No, it doesn't. I'm about to add an option at xawtv3 to allow users to manually select between mmap/normal, and to change the input/output devices. Well, pulseaudio is a bad behavioured boy that has several broken things, like preventing the removal of a V4L2 device for nothing. I won't be surprised if we notice even more problems with pulseaudio and V4L devices. At least on my test with fedora 15, audio is playing, even if pulseaudio is loaded. It should be noticed that the driver tries first to access the alsa driver directly, by using hw:0,0 output device. If it fails, it falls back to plughw:0,0. I'm not sure what's the name of the pulseaudio output, but I suspect that both are just bypassing pulseaudio, with is good ;) > > Regards, > > Hans > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
