On Wednesday 27 of May 2009 at 21:05:35, Mauro Carvalho Chehab wrote: > Em Sat, 23 May 2009 19:09:12 +0200 > > Oldrich Jedlicka <oldium.pro@xxxxxxxxx> escreveu: > > On Tuesday 19 of May 2009 at 19:54:18, Oldrich Jedlicka wrote: > > > On Tuesday 14 of April 2009 at 20:48:14, Oldrich Jedlicka wrote: > > > > Here is the fix for using the 32kHz sampling rate for TV and FM radio > > > > (ALSA). The TV uses 32kHz anyway (mode 0; 32kHz demdec on), radio > > > > works only with 32kHz (mode 1; 32kHz baseband). The ALSA wrongly > > > > reported 32kHz and 48kHz for everything (TV, radio, LINE1/2). > > > > > > > > Now it should be possible to just use the card without the need to > > > > change the capture rate from 48kHz to 32kHz. Enjoy :-) > > > > Hi Mauro, > > > > I put you on CC in my previous mail, but maybe it would be better to send > > it directly. So do you have any opinions about the approach described > > above/below? > > I did a look at saa713x datasheet. In thesis, it could be possible to > program the audio sampling rate divider for several rates including 32 kHz, > 44.1 kHz and 48 kHz. > > However, I suspect that only MONO is supported with rates different than 32 > kHz, since it is said there that AM/FM requires a nominal audio sample of > 32 kHz, and that NICAM nominal audio sample rate is 32 kHz. > > So, IMO, the right patch is just to allow samplings at 32 kHz Hi Mauro, I'm not good in programming the SAA7134, but I also have the SAA713x manual :-). I don't know if the NICAM mode is used for LINE1/LINE2, but if not - and if it uses the Video-lock mode - it can (or could) operate in 44.1kHz and 48kHz too. The manual talks about Video-mode and here is the note, that the FM/AM sound decoring requires a nominal audio sample rate of 32kHz. The code (saa7134-alsa.c) sets to use 32kHz for radio, it is not configurable - so this is where my patch applies. The Video-lock mode can use 32kHz, 44.1kHz and 48kHz. The NICAM can use only the 32kHz. From the code (again the saa7134-alsa.c) the TV sets to use the DEMDEC 32kHz mode and is not configurable - again my patch applies. So my only question is about the LINE1/LINE2, I do not understand the coding of SAA713x as much to be able to say anything about the mode of operation for LINE1/LINE2. Maybe somebody wants to use the 48kHz whenever possible on LINE1/LINE2 (quality reasons), so maybe limiting it there isn't good - I don't know, if it is possible to use it. Cheers, Oldrich. -- 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
