Sound issue with stk1160 driver

Sound issue with stk1160 driver

[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 perfectly, 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 left 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 included 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 seconds, and then the gray bars (see picture in the attachment).

>  What kind of video/audio source are you using to trigger this noise?
>  Do 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 inputs 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 and that the information he sent to me.

03.02.2014, 16:37, "Ezequiel Garcia" <elezegarcia@gmail.com>:

> šHi,
>
> šYesterday I spent all the day debugging this issue. The noise you report
> šis also present on any capture I do. In fact, I noticed it in the past but never
> šcared.
>
> šBad news are I still don't have a clue about it.
>
> šLet me explain you the differences between stk1160 and easycap audio.
> šstk1160 depends on a separate ac97-mixer driver to setup the AC97
> šparameters and on the snd-usb-audio driver to handle the audio stream.
>
> šeasycap does both things by itself.
>
> šSince I'm out of specific ideas, I'll try to implement the audio
> šhandling in stk1160 (just as easycap does) and see what happens.
> šHowever, it's not a simple task and it might take a few days/weeks.
>
> šFor now, you can use the easycap setting easycap_bars = 0 parameter
> što avoid those bars. I'm sorry for this regression!
>
> šIn addition, you can help by taking care of the bug report. This should
> šbe reported to the linux-sound mailing list:
> šhttp://vger.kernel.org/vger-lists.html#linux-sound
>
> šThe problem must be either in snd-usb-audio or in the sound/pci/ac97/..
> šcode. If you can report this (put me on Cc), it would be of great help.
>
> šThanks again and sorry for this inconvenience,
> šEzequiel

I hope very much for your help in solving this problem.

Thank you!

Re: Sound issue with stk1160 driver

[Evgeny Sagatov]

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 of 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. May 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" <sagatov@ya.ru>:
> Dear Sirs,
>
> I have EasyCAP device with STK1160+GM7113C+ALC101 chips.
> On my Ubuntu 12.04 with 3.11.0 kernel video capturing functioned perfectly, 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 left 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 included 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 seconds, and then the gray bars (see picture in the attachment).
>
>> ššWhat kind of video/audio source are you using to trigger this noise?
>> ššDo 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 inputs 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 and that the information he sent to me.
>
> 03.02.2014, 16:37, "Ezequiel Garcia" <elezegarcia@gmail.com>:
>
>> ššHi,
>>
>> ššYesterday I spent all the day debugging this issue. The noise you report
>> ššis also present on any capture I do. In fact, I noticed it in the past but never
>> ššcared.
>>
>> ššBad news are I still don't have a clue about it.
>>
>> ššLet me explain you the differences between stk1160 and easycap audio.
>> ššstk1160 depends on a separate ac97-mixer driver to setup the AC97
>> ššparameters and on the snd-usb-audio driver to handle the audio stream.
>>
>> ššeasycap does both things by itself.
>>
>> ššSince I'm out of specific ideas, I'll try to implement the audio
>> ššhandling in stk1160 (just as easycap does) and see what happens.
>> ššHowever, it's not a simple task and it might take a few days/weeks.
>>
>> ššFor now, you can use the easycap setting easycap_bars = 0 parameter
>> ššto avoid those bars. I'm sorry for this regression!
>>
>> ššIn addition, you can help by taking care of the bug report. This should
>> ššbe reported to the linux-sound mailing list:
>> ššhttp://vger.kernel.org/vger-lists.html#linux-sound
>>
>> ššThe problem must be either in snd-usb-audio or in the sound/pci/ac97/..
>> ššcode. If you can report this (put me on Cc), it would be of great help.
>>
>> ššThanks again and sorry for this inconvenience,
>> ššEzequiel
>
> I hope very much for your help in solving this problem.
>
> Thank you!