On Sun, Oct 17, 2021 at 01:54:31AM +0100, Mauro Carvalho Chehab wrote: > Em Sat, 16 Oct 2021 19:35:22 +0200 > Debucquoy Anthony <d.tonitch@xxxxxxxxx> escreveu: > > Don't top post. It makes really hard for people to follow the discussions. > > This time, I'll re-order the discussion for it to make sense. > > > On Fri, Oct 01, 2021 at 09:19:09AM +0200, Mauro Carvalho Chehab wrote: > > > Hi Anthony, > > > > > > Em Thu, 30 Sep 2021 15:51:22 +0200 > > > Debucquoy Anthony <d.tonitch@xxxxxxxxx> escreveu: > > > > > > > Hello, > > > > > > > > I have currently have a (Grabster AV 350) > > > > [https://www.terratec.de/details.php?artnr=10599&lang=en] > > > > (and 300 that work even less but I will do another thread for it I think) > > > > > > > > I can easily get video output out of it with /dev/video0 but the problem > > > > is that I can't get audio by any way > > > > > > ... > > > > > > > [ 7275.368159 ] em28xx 1-8:1.0: Identified as Terratec AV350 (card=68) > > > > [ 7275.368163 ] em28xx 1-8:1.0: analog set to isoc mode. > > > > [ 7275.368192 ] em28xx 1-8:1.0: Registering V4L2 extension > > > > [ 7275.497387 ] tvp5150 9-005c: tvp5150 (4.0) chip found @ 0xb8 (1-8:1.0) > > > > [ 7275.497396 ] tvp5150 9-005c: tvp5150am1 detected. > > > > [ 7278.429769 ] em28xx 1-8:1.0: Config register raw data: 0x50 > > > > [ 7278.470775 ] em28xx 1-8:1.0: AC97 vendor ID = 0x83847666 > > > > [ 7278.490776 ] em28xx 1-8:1.0: AC97 features = 0x6a90 > > > > [ 7278.490782 ] em28xx 1-8:1.0: Sigmatel audio processor detected (stac > > > > 9766) > > > > > > The em28xx devices use an external chip for audio, using AC97. > > > > > > As AC97 is an industry standard, it is possible for board vendors > > > to replace it with different chips. They do that with time, selecting > > > a different chip when they need/want. > > > > > > The boards entry at the em28xx has configurations for the device that > > > was used at the time the code was introduced, but this may not be > > > the case anymore for a newer device. > > > > > > Anyway, the AC97 chips have several different entries. From its > > > datasheet: > > > > > > https://www.digchip.com/datasheets/parts/datasheet/649/STAC9766-pdf.php > > > > > > It sees that it has the following input lines: > > > > > > pc beep > > > phone > > > aux > > > video > > > cd > > > mic > > > line in > > > > > > They also have a "Master" volume that the driver sets to be in 100% > > > (but some apps and pulseaudio might reduce it to 0%, causing the device > > > to be muted). > > > > > > Anyway, the AC97 Kernel support will expose all lines reported by the > > > hardware via an ALSA mixer. > > > > > > The AV 350 entry assumes that the "line in" mixer entry is the one > > > containing the audio. So, it will place the volume for such line > > > in 100%. > > > > > > However, maybe, on your device, some other input was used instead. > > > > > > If this is the case, all you need to do is to open a mixer, unmute > > > the right line and manually increase the volume. > > > > > > - > > > > > > There's a separate issue that might explain why some people > > > are using a different card: some boards require a command to > > > enable some pins (called GPIO). Those are used, among other > > > things, to enable/disable some external chips. In the case of > > > the original AV 350 that was used to add support for it, > > > it used some of those GPIOs to enable the AC97 inputs. > > > If your AV 350 requires a different setting, that will require > > > to patch the Kernel, but it is more likely that the problem on > > > your device is just due to a different AC97 volume. > > > Hey, I'm really sorry about Up this thread but I found some things that > > can help but I'm not experimented enough to understand how to make it > > work properly! > > > > By looking on the net with the info you gave me in the previous message, > > some people have request to try to use tvtime or xawtv ! > > > > So did I! and with tvtime, it was the first time I eared some song out > > of my device! > > Ok. It means that there's nothing wrong with the Kernel driver. > > What xawtv and tvtime does is that it starts a thread that does > something similar to: > > $ arecord -D hw:1 -r 48000 -c 2 -f S16_LE | aplay -D hw:0 > > E. g. the thread reads audio from the capture card (in the above > example, hw:1) and sends its output to another device (hw:0, on > the above example). > > > this is great news but I can't use it to record as I want! > > You need to pass the right alsa device to the video recorder application. > > E. g., using a command line command, it would be something like: > > $ mencoder -tv driver=v4l2:device=/dev/video0:norm=pal-b:width=720:height=576:input=0:alsa:adevice=hw.1":amode=1:forceaudio:fps=25 tv:// -o my_output.mpg -oac mp3lame -lameopts cbr:br=224 -ovc lavc -lavcopts dia=-2:vcodec=mpeg4:vbitrate=1500 -noodml > > I didn't test, but maybe some app like obs-studio would equally work, > provided that you set the audio input device to the one exported by > the em28xx driver, and that you set the right byte speed (if I'm not mistaken, > most em28xx devices use 48k, but this depends on the AC97 chipset). > > > By the way, the sound came out of one of my headset that I don't use but > > is still plug in my pc by usb! this is not the default on pulse neither > > on alsa (at least to my knowledge)! > > I guess there are parameters on both xawtv/tvtime to setup the audio > output device, but they offer limited support to control it. > > > Then I tried with xawtv and this is the opposite, it doesn't even bother > > to launch (rip) ^^ > > > > So maybe anyone know what tvtime does differently that make my device > > work ? > > > > Again, sorry for the up ? :'( > > Hopefully you can undestand! > > > > Thanks a lot for your help so far! Thanks a lot for your precious information! the problem is still there but I don't think (as u said) that this is a linux-media issue! I will explain everything to a mail for the alsa mailing list and try to get help there! Again, your help is really precious and I really respect your work for the linux community! Have a great day! Debucquoy Anthony Ps: sorry for the top-post (I assume is the fact that I wrote before the previous message) I will be more watchful in the future
