On 29.01.2018 19:39, NicoHood wrote: > On 01/29/2018 07:19 PM, Georg Chini wrote: >> On 29.01.2018 18:46, Nico wrote: >>> On 01/29/2018 03:52 PM, NicoHood wrote: >>>> On 01/29/2018 03:29 PM, Georg Chini wrote: >>>>> On 29.01.2018 14:44, NicoHood wrote: >>>>>> On 01/29/2018 01:39 PM, Georg Chini wrote: >>>>>>> On 29.01.2018 12:52, Nico wrote: >>>>>>>> Hi, >>>>>>>> I want to capture the audio stream of my TV with my PCI-E Toslink >>>>>>>> sound >>>>>>>> card and play it back on my usb XLR soundcard. The reason why I >>>>>>>> do that >>>>>>>> is to use my own music boxes rather than the TV speakers. With >>>>>>>> toslink + >>>>>>>> XLR I do not have problems with ground loops etc. >>>>>>>> >>>>>>>> I am using the pulseaudio loopback module with its default >>>>>>>> configuration. The problem is, that the delay between picture and >>>>>>>> sound >>>>>>>> is about one second off, and the longer I wait, the more delay it >>>>>>>> gets >>>>>>>> (30 seconds and more). It is no usable like this. >>>>>>>> >>>>>>>> I tried to play with the latencies of source, sink and the tv delay >>>>>>>> itself without sucess. I also tried streaming with pacat directly as >>>>>>>> described here: >>>>>>>> https://thelinuxexperiment.com/fix-pulseaudio-loopback-delay/ >>>>>>>> >>>>>>>> I also tried to change different parameters of the loopback >>>>>>>> module or >>>>>>>> the sources/sinks, but that did not help. I never changed any global >>>>>>>> pulseaudio config to avoid larger configuration issues. The CPU >>>>>>>> usage of >>>>>>>> pulseaudio is at 3% with the loopback module >>>>>>>> >>>>>>>> Can anyone help me to get rid of this lag? >>>>>>>> >>>>>>> Hi Nico, >>>>>>> >>>>>>> which version of PA are you using? Can you provide logs? >>>>>>> >>>>>>> Regards >>>>>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Georg >>>>>>> >>>>>> Hi Georg, >>>>>> oh sure I completely forgot: >>>>>> >>>>>> pulseaudio 11.1-1 (Arch Linux) >>>>>> uname -a: Linux zebes 4.14.15-1-ARCH #1 SMP PREEMPT Tue Jan 23 >>>>>> 21:49:25 >>>>>> UTC 2018 x86_64 GNU/Linux >>>>>> >>>>>> Here is a logfile: >>>>>> LANG=C pulseaudio -vvvv --log-time=1 > ~/pulseverbose.log 2>&1 >>>>>> https://gist.github.com/NicoHood/85976f426e1621e599253ee1a95230dd >>>>>> >>>>>> Regards >>>>>> Nico >>>>> This is weird. It looks like the source sample rate is so much higher >>>>> than the sink rate that module-loopback can't adapt. No idea why >>>>> this happens. Does it work with another input? >>>>> >>>>> >>>> I've tested it also with the builtin front microphone input (2nd >>>> revision on gist) and with the PCIE Analog line in (3rd gist revision). >>>> You can view the changes here: >>>> https://gist.github.com/NicoHood/85976f426e1621e599253ee1a95230dd/revisions >>>> >>>> >>>> The problem only occurs with the digital, optical TOSLINK input from my >>>> Samsung TV. For some other reason the sound distortion for the analog >>>> input is now (temporary) gone. However I still want to get that TOSLINK >>>> running :/ >>>> _______________________________________________ >>>> pulseaudio-discuss mailing list >>>> pulseaudio-discuss at lists.freedesktop.org >>>> https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss >>>> >>> As an additional test I send the audio to the TOSLINK output of the >>> soundcard, back to its input and setup loopback on the input again (to >>> the USB soundcard). With this method the sound has no lag. The >>> difference is that the toslink signal comes from the soundcard itself >>> rather than the TV. I have some smaller noises/distortion however >>> sometimes. Here is the log: >>> https://gist.github.com/NicoHood/6ef237649d97eaa69d9a78dd91eff34a >>> >> Somehow this still sounds like a sample rate mismatch. (A wild >> guess, I do not know how the signal chain works for a TOS-link) >> Have you tried setting your card to 48kHz? You can change >> default-sample-rate and alternate-sample-rate in daemon.conf >> both to 48000 and restart pulse to enforce this. >> >> > With 48kHz The sound is working properly now. The problem I got ~~now~~ > is that there is sound distortion in the recording. -> A reboot fixed that. > > Is there any negative effect when using 48kHz as default sample rate? Is > there a way to configure only the loopback module with this special > sample rate? (Sorry, I have no idea how audio works internally). And if > there is no other way than configuring the default sample rate, how can > is set this as user (without root) if possible? > > Thanks a lot so far :) > If the sound card supports it, PA will always use either the default or the alternative sample rate, whatever fits the current stream better, unless there is already a stream running on the card. So it should be enough to run module-loopback with rate=48000. Don't forget to change the values in daemon.conf back to their original values before you try it.
