media-workshop April 2014

media-workshop@linuxtv.org

7 participants
8 discussions

Meeting during this week in San Jose - at ELC week
by Mauro Carvalho Chehab 13 May '14

13 May '14

Hi Grant, We're still experiencing a high delay on patch series that contain DT patches, even with the recent DT changes. Are you in San Jose this week for ELC? If so, do you have time for an informal meeting, with me and some V4L2 sub-maintainers that will also be here during this week? Regards, Mauro

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[AGENDA] Second version
by Hans Verkuil 30 Apr '14

30 Apr '14

This is the list of topics for the Media mini-summit on May 2nd in San Jose. We plan to start at 9:00 and I assume we have the room until 18:00 (Mauro, can you confirm this?). This means we will probably have effectively 6 hours of discussions. Topics for the V4L2/DVB mini-summit: 9:00-9:20 Introduction 9:20-10:50 V4L2 Ambiguities (Hans Verkuil) This will have a large section devoted to composing/cropping/scaling. Draft presentation is available here: http://hverkuil.home.xs4all.nl/presentations/ambiguities3.odp 10:50-11:15 Break 11:15-11:30 Compound types in the control framework (Hans Verkuil) 11:30-12:30 Per-frame settings aka configuration stores (Hans Verkuil) 12:30-13:30 Lunch break 13:30-14:00 Integration of the of-graph helpers and the component framework (drivers/base/component.c) in V4L2 (Laurent Pinchart) 14:00-14:15 Patch review process (Laurent Pinchart) Several developers were unhappy with patch series posted a month before being rejected right before the mainline merge window. Should our process be improved in that area? 14:15-15:15 Linux media power management (Shuah Khan) 15:15-15:45 Break 15:45-16:45 DVB demux improvements brainstorming (Mauro Carvalho Chehab) 16:45-17:00 Demo of the revamped vivi driver (Hans Verkuil) 17:00-17:30 AVB Presentation (Hans Verkuil) If I missed topics, or you think the time for your section is too long/short, or if you need it moved to another time, then let me know. The times are approximate, in practice some topics will take more time than expected, others less. Experience from past summits shows that it will average out. Shuah, I allocated one hour for your presentation, do you think that is sufficient? Regards, Hans

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FYI - Late add media talk at ELC on May 1st afternoon
by Shuah Khan 30 Apr '14

30 Apr '14

My talk on Linux Media - Sharing Media Functions Nicely Across Drivers has been added to the agenda on May 1st 2 PM - 2:50 PM http://events.linuxfoundation.org/events/embedded-linux-conference/program/… Hope to see some of you there. -- Shuah -- Shuah Khan Senior Linux Kernel Developer - Open Source Group Samsung Research America(Silicon Valley) shuah.kh(a)samsung.com | (970) 672-0658

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DVB demux improvements brainstorm section
by Mauro Carvalho Chehab 18 Apr '14

18 Apr '14

I'd like to propose a theme with regards to DVB demux improvements. While we did a lot of work at the frontend API, the DVB API is almost the same as it were in 2005, lacking some interesting functionalities. The idea here is to have a brainstorm section in order to discuss some improvements, like: - add support for mmapped streams; - add support for dmabuf; - allow multiple sections to be filtered on the same PID; - allow multiple sections to be filtered at the same file descriptor. -- Regards, Mauro

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[AGENDA]: First draft version, please check!
by Hans Verkuil 16 Apr '14

16 Apr '14

This is the initial list of topics for the Media mini-summit on May 2nd in San Jose. We plan to start at 9:00 and I assume we have the room until 18:00 (Mauro, can you confirm this?). This means we will probably have effectively 6 hours of discussions. Topics for the V4L2/DVB mini-summit in no particular order: Hans Verkuil: - V4L2 Ambiguities This will have a large section devoted to composing/cropping/scaling. Draft presentation is available here: http://hverkuil.home.xs4all.nl/presentations/ambiguities3.odp 90 min - Compound types in the control framework 15 min - Per-frame settings aka configuration stores 30 min - Demo of the revamped vivi driver 15 min - AVB Presentation 30 min (TBC) Laurent Pinchart - Integration of the of-graph helpers and the component framework (drivers/base/component.c) in V4L2. - Format and selection rectangles interaction (Hans is working on adding test cases for this to the compliance tools and he reported that several points were not clear): can probably be folded into V4L2 Ambiguities. - Patch review process: several developers were unhappy with patch series posted a month before being rejected right before the mainline merge window. Should our process be improved in that area? Shuah Khan: - Linux media power management - problems, challenges and fixes Mauro Carvalho Chehab: - DVB demux improvements brainstorming Please let me know your estimate of how long your section will take to present and discuss. If I missed topics, please inform me asap. Laurent, can you confirm that your "Format and selection rectangles interaction" can be folded into the V4L2 Ambiguities section? Once I have the time estimates I'll send out a second draft where I order the topics. Regards, Hans

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[ANNOUNCE] media mini-summit on May, 2 in San Jose
by Mauro Carvalho Chehab 16 Apr '14

16 Apr '14

As discussed on our IRC #v4l channels, most of the core developers will be in San Jose - CA - USA for the Embedded Linux Conference. There are several subjects that we've been discussing those days that require a face to face meeting. So, We'll be doing a media mini-summit on May, 2 (Friday) at Marriott San Jose. Eventually, we may also schedule some BoFs during the week, if needed. In order to properly organize the event, I need the name of the developers interested on joining us, plus the themes proposed for discussions. As usual, we'll be using the media-workshop(a)linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it. Thanks! Mauro

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mini-summit: AVB Presentation
by Hans Verkuil 08 Apr '14

08 Apr '14

I'd like to give a small (20 min?) presentation about AVB (Audio Video Bridging, http://en.wikipedia.org/wiki/Audio_Video_Bridging) and possibilities to implement audio/video streaming and parts of AVDECC in ALSA/V4L2 (AVDECC = AVB Discovery, Enumeration, Connection management and Control). It's very early days, so this is more about what it is and what the advantages are of handling part of it in the kernel. Regards, Hans

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[Proposal] media mini-summit - Linux media power management - problems, challenges and fixes
by Shuah Khan 02 Apr '14

02 Apr '14

I am requesting that the following presentation/discussion to be added to the media mini-summit agenda. The intent is to do a very short presentation and leave time for discussion. Linux media power management - problems, challenges and fixes Media devices can be very complex to support in software - for example, a small USB TV stick is packed with several components providing the functionality to tune, stream analog and/or digital video and audio. Some hybrid devices support both analog, and digital TV tuning capability with or without a remote control capability. A single TV device, which connects to the PC on a USB bus, could have one or more I2C buses internally to implement tuning and remote control features. On Linux, several individual component drivers come together to provide full functionality on these media devices. For instance, a single digital USB TV stick will have a USB driver that acts as the front-end for several Linux TV media infrastructure components such as: Digital Video Broadcasting (dvb), Audio, and Video4linux (v4l2). Each of these extensions initialize and control their set of registers on the device with the aid of additional tuner and remote control drivers. As you can see, the infrastructure supporting one of these devices is complex and handling suspend/resume within the OS quickly becomes a challenge. It won't come as a too much of a surprise to hear that most media drivers don't handle power management properly. This is due to the lack of a good PM infrastructure inside the media core, as well as driver bugs in their suspend and resume code paths. This work also includes using devres infrastructure work to handle shared media resources such as tuner, demux etc. In this presentation, we will discuss what is being done to address these issues and also present an overview of PM infrastructure being considered for future kernel releases. -- Shuah -- Shuah Khan Senior Linux Kernel Developer - Open Source Group Samsung Research America(Silicon Valley) shuah.kh(a)samsung.com | (970) 672-0658

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media-workshop April 2014