From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evgeny Sagatov Date: Wed, 12 Feb 2014 20:01:11 +0000 Subject: Re: Sound issue with stk1160 driver Message-Id: <37561392235271@web25g.yandex.ru> List-Id: References: <6561391433979@web15h.yandex.ru> In-Reply-To: <6561391433979@web15h.yandex.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable To: linux-sound@vger.kernel.org The stk1160 driver has a problem with AC97 codec. Look at this picture http://sagatov.net/temp/sound-wave.png In the picture only the right audio channel connected. But for a fraction o= f a second channels are swapped. Please tell any ideas why this might happen? This driver source code, which is responsible for the sound. It is short. M= ay be specified any invalid parameter? http://lxr.free-electrons.com/source= /drivers/media/usb/stk1160/stk1160-ac97.c Please help those who are understands the AC97 codec programming. Data is not lost. But the audio channels are reversed. 03.02.2014, 17:26, "Evgeny Sagatov" : > Dear Sirs, > > I have EasyCAP device with STK1160+GM7113C+ALC101 chips. > On my Ubuntu 12.04 with 3.11.0 kernel video capturing functioned perfectl= y, but audio capturing have problem with sound clicks. > You can hear these sounds in the linked audio file (Initially both audio = inputs enabled and then I mute one, then both audio inputs.). > http://sagatov.net/temp/audio.wav > Clearly audible clicks in the headphones. A feeling that for a moment lef= t and right channels are swapped. > I tested three devices on three computers. I also tested the device on a = freshly installed Ubuntu 13.10. But the result is the same everywhere. > In MS Windows no clicks. > > I have tried to boot my Ubuntu 12.04 with the 3.2.0-58 kernel. > Turned out that the legacy driver is already installed. Probably it is in= cluded in Ubuntu distribution. > I have a beautiful sound in this case without any problems. > But I have a problem with the video :-) The video is displayed few second= s, and then the gray bars (see picture in the attachment). > >> =9A=9AWhat kind of video/audio source are you using to trigger this nois= e? >> =9A=9ADo you get the noise on all captures or only on some of them? > > I tried two different cameras and video player. Also I tried to leave inp= uts unconnected. > Noise is always, regardless of the source. > > Noise is better heard when only one audio channel is connected. A feeling= that for a split second sound goes to another channel and back. > > Earlier I have the correspondence with the developer of stk1160 driver an= d that the information he sent to me. > > 03.02.2014, 16:37, "Ezequiel Garcia" : > >> =9A=9AHi, >> >> =9A=9AYesterday I spent all the day debugging this issue. The noise you = report >> =9A=9Ais also present on any capture I do. In fact, I noticed it in the = past but never >> =9A=9Acared. >> >> =9A=9ABad news are I still don't have a clue about it. >> >> =9A=9ALet me explain you the differences between stk1160 and easycap aud= io. >> =9A=9Astk1160 depends on a separate ac97-mixer driver to setup the AC97 >> =9A=9Aparameters and on the snd-usb-audio driver to handle the audio str= eam. >> >> =9A=9Aeasycap does both things by itself. >> >> =9A=9ASince I'm out of specific ideas, I'll try to implement the audio >> =9A=9Ahandling in stk1160 (just as easycap does) and see what happens. >> =9A=9AHowever, it's not a simple task and it might take a few days/weeks. >> >> =9A=9AFor now, you can use the easycap setting easycap_bars =3D 0 parame= ter >> =9A=9Ato avoid those bars. I'm sorry for this regression! >> >> =9A=9AIn addition, you can help by taking care of the bug report. This s= hould >> =9A=9Abe reported to the linux-sound mailing list: >> =9A=9Ahttp://vger.kernel.org/vger-lists.html#linux-sound >> >> =9A=9AThe problem must be either in snd-usb-audio or in the sound/pci/ac= 97/.. >> =9A=9Acode. If you can report this (put me on Cc), it would be of great = help. >> >> =9A=9AThanks again and sorry for this inconvenience, >> =9A=9AEzequiel > > I hope very much for your help in solving this problem. > > Thank you!