Experiences with the easycap DC60 audio and video capture adapter on Linux

This Blog is dedicated to all owners of the STK1160 chip based EasyCAP (or identical) devices, who want to use it under Linux.

Activating audio for the STK1160 device: read the this post

German speaking users: read my article on ubuntuusers.de

The EasyCAP DC60 and its clones are cheap little USB analogue capturing devices which can be used for viewing and recording video under Linux from different sources like VHS tape recorders, satellitereceivers, camcorders ...

Friday, March 29, 2013

Features of the stk1160 driver in the kernel

Updated August 6 2014

The stk1160 driver in the kernel (3.7 and upward) supports:
  • video capturing
    • PAL at 25 fps at 720x576
    • NTFS at 30 fps at 720x480
    • S-Video from input Nr. 4
    • the CVBS + S-Video model and 
    • the four CVBS model (all four channels) 
  • audio capturing
    • must be enabled in the mixer settings (read more on this post)
    • audio capturing only from the CVBS + S-Video model with built in AC'97 chip (3 chip Easycap; 48000Hz model) is supported
Good to know
  • The Easycap works even if it is connected to an USB 2.0 hub.
  • Use a powered hub if you get a crampy picture.
    Some performance issues are caused by too low power provided by some small boards (like Raspberry PI).
  • Some USB 3.0 hosts may have bandwith limitation, then it can cause problems with stk1160.

Supported features
  • Two (or more) stk1160 devices working side by side on one system
    (If this is not possible, it's not a driver issue, but rather about USB bandwidth)
  • Switching channels/ inputs while capturing (with the v4l2-ctl tool - read more on this post.).
Not supported: (but supported by the legacy easycapdriver)
  • Famescaling
    Only full PAL or NTFS frames can be captured
    (this is important e.g. for settings in Zoneminder)
  • audio capturing from the 8000Hz Easycap
    The stk1160 driver doesn't support audio on
    the four CVBS model and on
    the the CVBS + S-Video model where the AC'97 chip is missing.
    (Adding support for the 8 bit ADC in the stk1160 chip is planned in the future.)
Known issues
  • Some  stk1160 based Easycaps don't work on the stk1160 driver but on the legacy easycap driver. (will be solved in kernel 3.12 !)
    Read more on this post:
  • Easycap device issues on the Raspberry Pi
    Read more on this post:

The stk1160 regression problem

Update Feb 13 2014

This issue described below is solved in kernel 3.12 (not 3.11). It affects Easycap devices with gm7113 chip, which is a clone of the Philips saa7113 chip.

I cannot verify by myself, so please report, if this problem is solved in kernel 3.12.

Ezequiel Garcia wrote:(28. 03. 13)

"There are a batch of stk1160 Easycaps that don't work on stk1160 but do work
on the legacy easycap driver. This is a known issue since Nov. 2012."

Saturday, March 23, 2013

Raspberry Pi and Easycap devices

Update Feb 13 2014

Some hints for checking:
  • Use a powered USB hub to conntect the STK1160 device to the RPI because Raspberry pi is not strong enough to power usb easycap directly.
  • Try the -zoom option in your mplayer command.
    The stk1160 driver in the kernel doesn't support (hardware-) framescaling.
    from mplayers manpage:

    Allow software scaling, where available. This will allow scaling with output drivers (like x11, fbdev) that do not support hardware scaling where MPlayer disables scaling by default for performance reasons.
    mplayer tv:// -tv driver=v4l2:device=/dev/video0 -vf scale=400:300 -zoom
  •  You can try mplayer2 instead of mplayer.
It would be nice, if someone could report if these hints are useful/ working.

legacy Information:

Summing up all the comments below this post and some forum posts I've read about that issue, I can say that many USB video capture devices and webcams are not working at all (or only at a very low resolution) on the raspberry pi because of a rpi related USB issue.

These USB problems on the rpi are still pending and I couldn't find any report that the stk1160 device or any other Easycap device is working acceptably on the RPI.

Mainly USB webcams which are supported by the uvcvideo driver (many but not all) are working on the pi. List of pi verified USB webcams

More information about the rpi USB issue
In this thread on the raspberrypi.org forum  (page 12 to 16)
In this thread on raspberrypi.stackexchange.com 
success with a modified em28xx driver


more legacy information:

Easycap devices (stk1160, empia, somagic) currently are causing some problems with standard Linux disributions on the Raspberry Pi because of some RPI related USB issues.
However, enhancements are in progress.

The Easycap device registers properly like under any other Linux system (when the driver is in the kernel), but the video data transport through the RPIs USB system doesn't work.
I suppose this issue affects many other v4l2 devices plugged into the RPIs USB.

Ezequiel Garcia reported to me the following:

"The problem with the RPI is that it has a crappy USB driver and USB hardware.
When that is solved, stk1160 will work. Probably will take a long time
because synopsis USB datasheet is not public."

Note: The RPI branch on Ezequiels github https://github.com/ezequielgarcia/stk1160-standalone/tree/rpi is broken and doesn't work at all!