On Monday 26 October 2015 00:54:07 Hans Verkuil wrote:
Hi all,
A late (small) change:
The break was moved up by 30 min since Shuah's talk moved up by the same amount.
Regards,
Hans
Draft agenda for the media workshop October 26, 2015, Seoul, South Korea
Room: TBD
Please be on time! We start at 9 am, we have a full agenda, so we want to make good use of the time.
9:00-9:15: Get laptops hooked up, the projector running, wireless configured, your coffee cup filled, etc. etc. :-)
9:15-9:30: Hans: Introduction
9:30-10:15: Pawel: Update on codec APIs
10:15-10:30: Mauro: kABI documentation improvements
For reference, the DRM example I mentioned during the discussion is in
drivers/gpu/drm/drm_atomic_helper.c (look for "DOC: overview) Documentation/DocBook/drm.tmpl (look for "!Pdrivers/gpu/drm/drm_atomic_helper.c overview")
10:30-11:45: Break Allows time for attending Shuah's talk:
http://korealinuxforum2015.sched.org/event/f59175cc49f866dbc9bebc36f86fe663
#.ViTJynMU5Bf
11:45-12:15: Junghak: new uAPI for DVB to use streaming I/O
12:15-13:00: Hans: Should we replace v4l2_buffer with a new struct that is y2038-safe and that can be cleaned up and extended? (Think proper support for HW timestamps, etc.). See: https://patchwork.linuxtv.org/patch/31413/
And perhaps use this redesign to add support for multiple streams over
one
video node? I saw an example where the HW combines two streams into one, basically an m2m device, but today you'd need three nodes: two out and
one
capture in order to implement this.
13:00-14:30: Lunch
14:30-14:45: Hans: Proposal for adding support for HW colorspace conversion.
14:45-15:00: Hans: poll() behavior for output streams.
15:00-15:15: Hans: Status update of the CEC framework patch series.
15:15-16:00: Hans: Should the v4l2 core just call try_format to validate the format passed in by VIDIOC_CREATE_BUFFERS? Few drivers validate the format and if they do they usually do only partial validation. It's unclear what should happen here. Always calling try_format would also help the vb2 core code. Also discuss DELETE_BUFFERS.
16:00-16:15: Break
16:15-16:30: Mauro: Status update
MC discussions: very tentative, and I'm just listing the topics without scheduling them and in no particular order:
Mauro: Discuss dynamic subtree removal. The workshop might be too soon to discuss this.
Hans: How to implement VIDIOC_SUBDEV_QUERYCAP? (15 min)
Shuah: ENT_F_IO appears to be too generic, requiring additional steps to determine what kind of IO function it is really is. I propose preserving and allowing enough uniqueness to enable drivers to tag the functions when they create them. For example, if AUDIO functions are all tagged ENT_F_IO, bridge driver has to determine what kind of IO it really is. This requires finding the Interface entity associated with the function entity or comparing entity name strings. Instead, if a function can be tagged as Audio Capture when it gets created, these additional steps aren't necessary.
I estimate 15 min for this topic if we need this.
Shuah: Discuss snd-usb-audio control interface mapping to media. snd-usb-audio creates a control device file which could be exposed in a media graph. In some cases, it is a simple mixer control. Expose ENT_F_MIXER entity with an associated interface node MEDIA_INTF_T_ALSA_CONTROL
17:30-17:45: Hans: Discuss future improvements to the workshop format. Right now (as is clear from this schedule) the discussions are very technical, which makes it hard for non-core developers to attend. Perhaps we should do a split format: a half or full day of status updates, discussions to improve application integration, followed by core-developer-only discussions.