Re: em28xx, sound problems, STV40, linux 3.7.1

["Frank Schäfer" <fschaefer.oss@googlemail.com>]

Hi,

Am 01.01.2013 21:02, schrieb Lluís Batlle i Rossell:
> Hello,
>
> I'm testing a STV40 usb card, and I've some problems that disables me from
> capturing audio+video. I'm on linux 3.7.1.
>
> 1) Capturing the video with ffmpeg mutes the audio. Simply doing.
>   $ ffmpeg -f video4linux2 -i /dev/video1 out.flv
>
>   Previous to running ffmpeg, I've arecord with "-V mono", and the
>   vumeter goes to 0% once running that ffmpeg line.
>
> 2) The card does not advertise audio controls (like mute), through
>   "v4l2-ctl --list-ctrls"
>
> 3) The card muting and unmuting works fine using V4L2_CID_AUDIO_MUTE
>   But "v4l2-ctl -c mute=0" can't be used because 'mute' isn't advertised.
>   Once the card is muted, any call to arecord records all samples zero.
>   I mention that, because snd_em28xx_capture_open() looks like meant to
>   unmute.
>
> 4) If something captures the sound (muted), and still capturing, I
>   unmute using V4L2_CID_AUDIO_MUTE, the samples arrive broken. I don't
>   know how to describe the noisy effect: http://viric.name/~viric/tmp/noise.wav
>   (only one channel was connected, of the stereo input)
>
> Due to 1) and 4), trying to capture audio+video with ffmpeg results in
> no-sound (muted), but if enabling it with a program apart while capturing using
> V4L2_CID_AUDIO_MUTE, the sound recorded by ffmpeg is crippled.
>
> Of course, I've no idea why the audio goes muted at video capture start.
>
> As a final note apart, the implementation of vidioc_g_audio fills a->name
> based on the incoming structure, instead of the later initialized a->index. I
> think it's wrong. That's what makes "v4l2-ctl --get-audio-input" report "1
> (Television)", while it should show "1 (Line In)".
>
> Additionally, "v4l2-ctl --list-audio-inputs" doesn't show any input either.
>
> As a note, here is the kernel information about the card I have:
> [45161.345491] em28xx: New device  USB 2861 Device (SVEON STV40) @ 480 Mbps (1b80:e309, interface 0, class 0)
> [45161.345500] em28xx: Video interface 0 found
> [45161.345504] em28xx: DVB interface 0 found
> [45161.345592] em28xx #0: chip ID is em2860
> [45161.456962] em28xx #0: i2c eeprom 00: 1a eb 67 95 80 1b 09 e3 50 00 20 03 6a 3c 00 00
> [45161.456988] em28xx #0: i2c eeprom 10: 00 00 04 57 06 02 00 00 00 00 00 00 00 00 00 00
> [45161.457029] em28xx #0: i2c eeprom 20: 02 00 01 00 f0 00 01 00 00 00 00 00 5b 00 00 00
> [45161.457049] em28xx #0: i2c eeprom 30: 00 00 20 40 20 80 02 20 01 01 02 01 00 00 00 00
> [45161.457068] em28xx #0: i2c eeprom 40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [45161.457086] em28xx #0: i2c eeprom 50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [45161.457105] em28xx #0: i2c eeprom 60: 00 00 00 00 00 00 00 00 00 00 3c 03 55 00 53 00
> [45161.457154] em28xx #0: i2c eeprom 70: 42 00 20 00 32 00 38 00 36 00 31 00 20 00 44 00
> [45161.457173] em28xx #0: i2c eeprom 80: 65 00 76 00 69 00 63 00 65 00 20 00 28 00 53 00
> [45161.457192] em28xx #0: i2c eeprom 90: 56 00 45 00 4f 00 4e 00 20 00 53 00 54 00 56 00
> [45161.457210] em28xx #0: i2c eeprom a0: 34 00 30 00 29 00 00 00 00 00 00 00 00 00 00 00
> [45161.457229] em28xx #0: i2c eeprom b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [45161.457247] em28xx #0: i2c eeprom c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [45161.457265] em28xx #0: i2c eeprom d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [45161.457283] em28xx #0: i2c eeprom e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [45161.457302] em28xx #0: i2c eeprom f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> [45161.457327] em28xx #0: EEPROM ID= 0x9567eb1a, EEPROM hash = 0xa3963040
> [45161.457332] em28xx #0: EEPROM info:
> [45161.457335] em28xx #0:       AC97 audio (5 sample rates)
> [45161.457338] em28xx #0:       500mA max power
> [45161.457343] em28xx #0:       Table at 0x04, strings=0x3c6a, 0x0000, 0x0000
> [45161.457350] em28xx #0: Identified as Easy Cap Capture DC-60 (card=64)
> [45161.661731] saa7115 9-0025: saa7113 found (1f7113d0e100000) @ 0x4a (em28xx #0)
> [45162.049366] em28xx #0: Config register raw data: 0x50
> [45162.061248] em28xx #0: AC97 vendor ID = 0x83847650
> [45162.067100] em28xx #0: AC97 features = 0x6a90
> [45162.067110] em28xx #0: Empia 202 AC97 audio processor detected
> [45162.301273] em28xx #0: v4l2 driver version 0.1.3
> [45162.822556] em28xx #0: V4L2 video device registered as video1
> [45162.822565] em28xx #0: V4L2 VBI device registered as vbi0
>
> Regards,
> Lluís.
>

Thank you for reporting this issue.
Is there any known kernel version where this has been working ?

Regards,
Frank