Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
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@linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it.
Thanks! Mauro
On 08/13/14 15:14, Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
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@linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it.
Yeah, I'll be there.
Topics:
- A presentation on colorspaces (Do *you* know what to put in the v4l2_pix_format colorspace field? And why should it matter?) - The usual API Ambiguities session (tentative, but likely)
Possibly others, it's too early to tell.
I would also suggest a topic to discuss the upstreaming procedures: what is working, what isn't, how to improve.
Regards,
Hans
Hi,
On 08/13/2014 03:25 PM, Hans Verkuil wrote:
On 08/13/14 15:14, Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
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@linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it.
Yeah, I'll be there.
Topics:
- A presentation on colorspaces (Do *you* know what to put in the v4l2_pix_format colorspace field? And why should it matter?)
- The usual API Ambiguities session (tentative, but likely)
Possibly others, it's too early to tell.
I would also suggest a topic to discuss the upstreaming procedures: what is working, what isn't, how to improve.
I'll be in Dusseldorf for plumbers during these days. But I'm leading the wayland microconf there, so that is where my priorities will be.
I may pop up to say hi to you all. If there is a specific topic or 2 you would like me to join for that can likely be arranged, assuming you plan them on the other day as the wayland miniconf.
Regards,
Hans
On Wed, Aug 13, 2014 at 10:14 PM, Mauro Carvalho Chehab m.chehab@samsung.com wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
I will be there as well. I would like to present/discuss: - Existing codec API ambiguities; - A proposal for a new codec API extension/mode for HW codecs that can't parse elementary streams;
May have more later, depending on how full the topic list would be.
Hi Mauro,
On Wednesday 13 August 2014 10:14:11 Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
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@linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it.
Thank you for organizing this. I'll be in Düsseldorf the whole week for ELCE and LPC, and I will need to attend the IOMMU microconference at LPC on Friday the 17th in the afternoon. Apart from that I'm interested and happy to participate in the media mini-summit.
Regarding topics, I'm thinking about runtime reconfiguration of pipelines, but it's a bit early to tell. I have customer demand for that, but no exact schedule yet, so it might be too early.
Hello
I will be the whole week in Dusseldorf. I would like to talk about multi selections and dead pixel api.
Thanks On 14 Aug 2014 07:42, "Laurent Pinchart" laurent.pinchart@ideasonboard.com wrote:
Hi Mauro,
On Wednesday 13 August 2014 10:14:11 Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
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@linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it.
Thank you for organizing this. I'll be in Düsseldorf the whole week for ELCE and LPC, and I will need to attend the IOMMU microconference at LPC on Friday the 17th in the afternoon. Apart from that I'm interested and happy to participate in the media mini-summit.
Regarding topics, I'm thinking about runtime reconfiguration of pipelines, but it's a bit early to tell. I have customer demand for that, but no exact schedule yet, so it might be too early.
-- Regards,
Laurent Pinchart
media-workshop mailing list media-workshop@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/media-workshop
Hello
I will also be in Düsseldorf the whole week for ELCE and LPC. I would love to attend the media mini-summit.
I am interested in multiselection, deadpixels API and multiple timestamps per buffer.
Thank you very much!
On Thu, Aug 14, 2014 at 1:43 PM, Laurent Pinchart laurent.pinchart@ideasonboard.com wrote:
Hi Mauro,
On Wednesday 13 August 2014 10:14:11 Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
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@linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it.
Thank you for organizing this. I'll be in Düsseldorf the whole week for ELCE and LPC, and I will need to attend the IOMMU microconference at LPC on Friday the 17th in the afternoon. Apart from that I'm interested and happy to participate in the media mini-summit.
Regarding topics, I'm thinking about runtime reconfiguration of pipelines, but it's a bit early to tell. I have customer demand for that, but no exact schedule yet, so it might be too early.
-- Regards,
Laurent Pinchart
media-workshop mailing list media-workshop@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/media-workshop
Hi Ricardo,
On Tuesday 19 August 2014 16:48:19 Ricardo Ribalda Delgado wrote:
Hello
I will also be in Düsseldorf the whole week for ELCE and LPC. I would love to attend the media mini-summit.
I am interested in multiselection, deadpixels API and multiple timestamps per buffer.
Could you elaborate a bit on that last point ? What kind of timestamps would you need, and what are the use cases ?
Hello Laurent
Could you elaborate a bit on that last point ? What kind of timestamps would you need, and what are the use cases ?
Right now we only have one timestamp field on the buffer structure, it might be a good idea to leave space for some more.
My user case is a camera that is recording a conveyor belt at a very high frame rate. Instead of tracking the objects on the image with I use one or more encoders on the belt. The encoder count is read on vsync and kept it on a register(s). When an image is ready, the cpu starts the dma and read this "belt timestamps" registers.
It would be nice to have an standard way to expose this alternative timestamps or at least find out if I am the only one with this issue and/or how you have solve it :)
Best regards!
On Tuesday 19 August 2014 18:29:08 Ricardo Ribalda Delgado wrote:
Hello Laurent
Could you elaborate a bit on that last point ? What kind of timestamps would you need, and what are the use cases ?
Right now we only have one timestamp field on the buffer structure, it might be a good idea to leave space for some more.
My user case is a camera that is recording a conveyor belt at a very high frame rate. Instead of tracking the objects on the image with I use one or more encoders on the belt. The encoder count is read on vsync and kept it on a register(s). When an image is ready, the cpu starts the dma and read this "belt timestamps" registers.
It would be nice to have an standard way to expose this alternative timestamps or at least find out if I am the only one with this issue and/or how you have solve it :)
I have a similar use cases. UVC transmits a device clock timestamp to the host, as well as the corresponding USB SOF counter value. This can be used to translate the device clock timestamp to a host timestamp. The uvcvideo driver is currently performing that translation in the kernel, but moving it to userspace would allow more accurate host timestamp computation by using floating-point math.
In a similar fashion CSI2 cameras transmit a 16-bit frame number to the receiver. That number is currently expanded to 32-bits by the driver and passed to userspace in the v4l2_buffer sequence number. That's fine from a kernel point of view, but in userspace the sequence number is lost when using the gstreamer v4l2src element.
Have you thought about how you would like to implement those advanced timestamps ? Reusing the v4l2_buffer timecode field might be an option, but I'm not sure whether it would be the best one. Using a metadata plane also comes to mind.
On 08/19/2014 09:00 PM, Laurent Pinchart wrote:
On Tuesday 19 August 2014 18:29:08 Ricardo Ribalda Delgado wrote:
Hello Laurent
Could you elaborate a bit on that last point ? What kind of timestamps would you need, and what are the use cases ?
Right now we only have one timestamp field on the buffer structure, it might be a good idea to leave space for some more.
My user case is a camera that is recording a conveyor belt at a very high frame rate. Instead of tracking the objects on the image with I use one or more encoders on the belt. The encoder count is read on vsync and kept it on a register(s). When an image is ready, the cpu starts the dma and read this "belt timestamps" registers.
It would be nice to have an standard way to expose this alternative timestamps or at least find out if I am the only one with this issue and/or how you have solve it :)
I have a similar use cases. UVC transmits a device clock timestamp to the host, as well as the corresponding USB SOF counter value. This can be used to translate the device clock timestamp to a host timestamp. The uvcvideo driver is currently performing that translation in the kernel, but moving it to userspace would allow more accurate host timestamp computation by using floating-point math.
In a similar fashion CSI2 cameras transmit a 16-bit frame number to the receiver. That number is currently expanded to 32-bits by the driver and passed to userspace in the v4l2_buffer sequence number. That's fine from a kernel point of view, but in userspace the sequence number is lost when using the gstreamer v4l2src element.
Have you thought about how you would like to implement those advanced timestamps ? Reusing the v4l2_buffer timecode field might be an option, but I'm not sure whether it would be the best one. Using a metadata plane also comes to mind.
Just my two cents: I think the timecode field should be reused for this as a way of storing driver/hardware-specific timestamps. Such timestamps are likely to be different for different hardware since I do not think that hardware timestamps can always be converted reliably to the kernel time. They may just be numbers that software needs to interpret according to what hardware was used.
M2M devices already copy the timecode field when copying frames (or at least they should), so changing v4l2_timecode to a union would make sense as that behavior of m2m devices remains preserved for hardware timestamps.
Regards,
Hans
On Wed, 13 Aug 2014, Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in DÃŒsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
In order to properly organize the event, I need the name of the developers interested on joining us, plus the themes proposed for discussions.
I'll likely be able to attend too. ATM I'm working on camera support in Android. I think Hans discussed related topics at the previous summit in the US too, which I didn't manage to attend unfortunately. I'll try to double-check results of those discussions and see which topics I'd be interested in discussing further.
On a related note, since I live something like 80km from the venue, I was thinking about possibly helping to organise a media event in my town - in Aachen, or in Düsseldorf itself or in neighbouring Cologne (Köln). Let me know if there's interest. We could use Saturday the 18th of October for that.
Thanks Guennadi
As usual, we'll be using the media-workshop@linuxtv.org ML for specific discussions about that, so the ones interested on participate are requested to subscribe it.
Thanks! Mauro
Guennadi Liakhovetski writes:
I'll likely be able to attend too. ATM I'm working on camera support in Android. I think Hans discussed related topics at the previous summit in the US too, which I didn't manage to attend unfortunately. I'll try to double-check results of those discussions and see which topics I'd be interested in discussing further.
I'll also try to be there for the mini-summit. So, if anybody wants to discuss APIs for DVB-T2/C2, CI, modulators, DVB network streaming or anything else related to DVB drivers ...
On a related note, since I live something like 80km from the venue, I was thinking about possibly helping to organise a media event in my town - in Aachen, or in Düsseldorf itself or in neighbouring Cologne (Köln). Let me know if there's interest. We could use Saturday the 18th of October for that.
I also live just 50km from the venue.
Regards, Ralph
Hi Mauro,
Am Mittwoch, den 13.08.2014, 10:14 -0300 schrieb Mauro Carvalho Chehab:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
In order to properly organize the event, I need the name of the developers interested on joining us, plus the themes proposed for discussions.
I'd like to participate in the media mini-summit. Here are some themes I'd be interested in:
- Helping userspace to use mem2mem devices; clarification of encoder/decoder handling, clarification of format/size setting in case of dependencies between input and output formats, possibly broad categorisation of mem2mem devices (encoder, decoder, scaler, rotator, csc/filter, ...)
- Hierarchical media devices - what if you have a lot of media entities and some of them are more closely related to each other than others.
regards Philipp
Hi Philipp,
On Fri, Aug 22, 2014 at 10:09 PM, Philipp Zabel p.zabel@pengutronix.de wrote:
- Helping userspace to use mem2mem devices; clarification of encoder/decoder handling, clarification of format/size setting in case of dependencies between input and output formats, possibly broad categorisation of mem2mem devices (encoder, decoder, scaler, rotator, csc/filter, ...)
I'm planning a session on codec API, would like to specify it in better detail and clear up ambiguities. If you'd have a list of issues that should be clarified, it would be very useful to add to discussion.
Hi Mauro,
On Wed, Aug 13, 2014 at 10:14:11AM -0300, Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
In order to properly organize the event, I need the name of the developers interested on joining us, plus the themes proposed for discussions.
I'll be coming to the Media workshop.
I'd like to discuss the Android camera HAL API v3 and what kind of requirements it brings to V4L2. That's the new Android camera interface and it's quite a bit different from the old one. The requirements as such, even if they come from Android directly, mostly have technical merit on their own.
As far as I remember, there was at least a plan to discuss this in an earlier summit but I haven't found any written notes on the topic.
On 09/01/2014 01:47 PM, Sakari Ailus wrote:
Hi Mauro,
On Wed, Aug 13, 2014 at 10:14:11AM -0300, Mauro Carvalho Chehab wrote:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
There is a perfect opportunity to discuss the media Kernel-Userspace API improvements that are required for newer devices to work. So, we hope to have there the major Kernel contributors to the media subsystem, and some people working on userspace, in order to be sure that we'll match the needs required on userspace.
In order to properly organize the event, I need the name of the developers interested on joining us, plus the themes proposed for discussions.
I'll be coming to the Media workshop.
I'd like to discuss the Android camera HAL API v3 and what kind of requirements it brings to V4L2. That's the new Android camera interface and it's quite a bit different from the old one. The requirements as such, even if they come from Android directly, mostly have technical merit on their own.
As far as I remember, there was at least a plan to discuss this in an earlier summit but I haven't found any written notes on the topic.
I don't believe this was ever discussed explicitly. However, my work on compound control types and the support for per-frame configuration (based on the control framework as well) is in part driven by the camera v3 API requirements.
I plan to discuss this during the summit, but in the meantime you can take a look at http://git.linuxtv.org/cgit.cgi/hverkuil/media_tree.git/log/?h=confstore which has an initial implementation for this.
It needs a bit more work, but it's mostly done.
Regards,
Hans
Hi,
Am Mittwoch, den 13.08.2014, 10:14 -0300 schrieb Mauro Carvalho Chehab:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
Is this a tentative schedule, or is the date set? I.e. can I book a hotel until Friday now and not worry about having to reschedule?
thanks Philipp
Em Tue, 02 Sep 2014 12:03:34 +0200 Philipp Zabel p.zabel@pengutronix.de escreveu:
Hi,
Am Mittwoch, den 13.08.2014, 10:14 -0300 schrieb Mauro Carvalho Chehab:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
Is this a tentative schedule, or is the date set? I.e. can I book a hotel until Friday now and not worry about having to reschedule?
It is all set.
Regards, Mauro
Hey all... It looks like I will be in Dusseldorf that week as well. :-) See you next month!
-Mike Ira Krufky
On Tue, Sep 2, 2014 at 8:58 AM, Mauro Carvalho Chehab m.chehab@samsung.com wrote:
Em Tue, 02 Sep 2014 12:03:34 +0200 Philipp Zabel p.zabel@pengutronix.de escreveu:
Hi,
Am Mittwoch, den 13.08.2014, 10:14 -0300 schrieb Mauro Carvalho Chehab:
Hi,
As there are still too things to be discussed in order to improve media stuff, and most of the developers nowadays are located in Europe and usually go to ELCE, we're scheduling a two day mini-summit in Düsseldorf, Germany, on Thrusday/Friday.
Is this a tentative schedule, or is the date set? I.e. can I book a hotel until Friday now and not worry about having to reschedule?
It is all set.
Regards, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
-
Guennadi Liakhovetski -
Hans de Goede -
Hans Verkuil -
Laurent Pinchart -
Mauro Carvalho Chehab -
Michael Ira Krufky -
Pawel Osciak -
Philipp Zabel -
Ralph Metzler -
Ricardo Ribalda Delgado -
Sakari Ailus