linux/drivers/media
Laurent Pinchart 23867b2511 V4L/DVB (9661): uvcvideo: Commit streaming parameters when enabling the video stream
Sonix-based cameras seem to require the host to commit video streaming
parameters before selecting the alternate endpoint. While most applications
issue a VIDIOC_S_FMT ioctl before starting streaming, this is not required
by the V4L2 specification.

The problem has been noticed on Ubuntu 8.10 with applications using libv4l.
The library blocks VIDIOC_S_FMT calls when the requested format is identical
to the currently selected format. As the driver commits video streaming
parameters when initialising the device, only the first run of a
libv4l-enabled application would succeed.

For the sake of completeness, experiment showed that the camera keeps sending
12 bytes isochronous packets (header only, no data) without toggling the FID
bit if video streaming parameters haven't been committed before selecting the
alternate endpoint.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-29 17:53:36 -02:00
..
common V4L/DVB (9638): drivers/media: use ARRAY_SIZE 2008-12-29 17:53:34 -02:00
dvb V4L/DVB (9637): usb vendor_ids/product_ids are __le16 2008-12-29 17:53:34 -02:00
radio V4L/DVB (9540): dsbr100: add disabled controls and fix version 2008-12-29 17:53:30 -02:00
video V4L/DVB (9661): uvcvideo: Commit streaming parameters when enabling the video stream 2008-12-29 17:53:36 -02:00
Kconfig V4L/DVB (8392): media/Kconfig: Convert V4L1_COMPAT select into "depends on" 2008-07-20 07:28:49 -03:00
Makefile V4L/DVB (8274): sms1xxx: build cleanup after driver relocation 2008-07-20 07:20:56 -03:00