advice on Easycap dongles and VBI interface..
i'm working on a project for legacy support of a teletext server with composite output interface.
i supposed to "ingest" teletext using the /dev/vbi support on linux so i've got an Easycap dongle
Bus 001 Device 008: ID 05e1:0408 Syntek Semiconductor Co., Ltd STK1160 Video Capture Device
AFAIK (i didn't open) it's using a video decoder SC7113 supposed to be a clone of SAA7113.
this device is supposed to work on an Ubuntu 12.04 with old kernel 3.2 so i had to blacklist the stock "RE" kernel module easycap and install the "retrofit" from here:
https://github.com/ezequielgarcia/stk1160-standalone
i see the saa7115 is loaded and i can also see audio and video through mplayer..
$ lsmod Module Size Used by saa7115 18447 1 stk1160 27732 0 videobuf2_core 28148 1 stk1160 snd_ac97_codec 110213 1 stk1160 ....
but in the dev fs there's no sign of /dev/vbi interface..
so my questions are:
- are these SAA7113 clones really copycat with all the features supported?
- has the SAA711x driver ever been used for /dev/vbi feature? i used to work with Bt878 cards for that feature.
- is the stock 3.x mainline kernel of the stk1160 really improved/different/VBI enabled?
- is there a way to extract VBI lines on /dev/video0?
- is there an easy way to enable or at least test (directly on the USB interface) the VBI interface?
- finally which approach do you suggest for supporting this ancient feature, if feasibiliy tests are ok:
- a libusb quick hack?
- an implementation of the bindings between user level /dev/vbi and
underlying SAA711x routines?
bests
andrea venturi
Hi Andrea,
Quoted 25 lines · Andrea Venturi
i'm working on a project for legacy support of a teletext server with composite output interface.
i supposed to "ingest" teletext using the
/dev/vbisupport on linux so i've got an Easycap dongleBus 001 Device 008: ID 05e1:0408 Syntek Semiconductor Co., Ltd STK1160 Video Capture Device
AFAIK (i didn't open) it's using a video decoder SC7113 supposed to be a clone of SAA7113.
this device is supposed to work on an Ubuntu 12.04 with old kernel 3.2 so i had to blacklist the stock "RE" kernel module easycap and install the "retrofit" from here:
https://github.com/ezequielgarcia/stk1160-standalone
i see the saa7115 is loaded and i can also see audio and video through mplayer..
$ lsmod Module Size Used by saa7115 18447 1 stk1160 27732 0 videobuf2_core 28148 1 stk1160 snd_ac97_codec 110213 1 stk1160 ....
Quoted 6 lines
but in the dev fs there's no sign of
/dev/vbiinterface..so my questions are:
- are these SAA7113 clones really copycat with all the features supported?
I believe so, yes.
Quoted 2 lines
- has the SAA711x driver ever been used for
/dev/vbifeature? i used to work with Bt878 cards for that feature.
It's been tested for saa7114 and saa7115, but I'm not sure if it was ever tested for saa7113. The chip can do it, and the saa7115 driver should as well, but the combination of saa7113 + VBI is very rare.
Quoted 2 lines
- is the stock 3.x mainline kernel of the stk1160 really improved/different/VBI enabled?
No, it doesn't have VBI support.
Quoted 1 line
- is there a way to extract VBI lines on
/dev/video0?
No.
Quoted 2 lines
- is there an easy way to enable or at least test (directly on the USB interface) the VBI interface?
No.
Quoted 4 lines
- finally which approach do you suggest for supporting this ancient feature, if feasibiliy tests are ok: - a libusb quick hack? - an implementation of the bindings between user level
/dev/vbiand underlying SAA711x routines?
The problem is that I don't believe we have any stk1160 documentation. And I wonder if the device can support VBI at all.
You are better off choosing devices that already have VBI support: the em28xx supports it, so do bt8xx, cx18 and ivtv.
Regards,
Hans
Hi Andrea and Hans,
Quoted 7 lines · Hans Verkuil
Quoted 5 lines
- finally which approach do you suggest for supporting this ancient feature, if feasibiliy tests are ok: - a libusb quick hack? - an implementation of the bindings between user level
/dev/vbiand underlying SAA711x routines?The problem is that I don't believe we have any stk1160 documentation.
I do have the stk1160 chip datasheet. However, it's not publicly available and I'm not sure I should disclose it (although syntek never advise me against it). In additio, the datasheet is not very verbose and the information is scarce and often incomplete.
Quoted 2 lines
And I wonder if the device can support VBI at all.
Apparently it does: at least there's a flag to "enable" VBI mode.
Quoted 3 lines
You are better off choosing devices that already have VBI support: the em28xx supports it, so do bt8xx, cx18 and ivtv.
I agree with this. I don't have any VBI source so there's no way I can work on this (not to mention it's not something lots of users need).
Signature · 3 lines
Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com