On Mon, May 11, 2020 at 01:25:23PM +0200, Dmitry Sepp wrote: > Hi Saket, > > On Montag, 11. Mai 2020 13:05:53 CEST Saket Sinha wrote: > > Hi Keiichi, > > > > I do not support the approach of QEMU implementation forwarding > > requests to the host's vicodec module since this can limit the scope > > of the virtio-video device only for testing, > > That was my understanding as well. > > > which instead can be used with multiple use cases such as - > > > > 1. VM gets access to paravirtualized camera devices which shares the > > video frames input through actual HW camera attached to Host. > > This use-case is out of the scope of virtio-video. Initially I had a plan to > support capture-only streams like camera as well, but later the decision was > made upstream that camera should be implemented as separate device type. We > still plan to implement a simple frame capture capability as a downstream > patch though. > > > > > 2. If Host has multiple video devices (especially in ARM SOCs over > > MIPI interfaces or USB), different VM can be started or hotplugged > > with selective video streams from actual HW video devices. > > We do support this in our device implementation. But spec in general has no > requirements or instructions regarding this. And it is in fact flexible enough > to provide abstraction on top of several HW devices. Hmm I agree if it's just for pass-through of host devices that's a very limited usecase. Not out of scope for virtio, but let's make it clear it's pass-through in the device name, so that if people want to create a virtualizeable interface down the road they don't feel blocked. > > > > Also instead of using libraries like Gstreamer in Host userspace, they > > can also be used inside the VM userspace after getting access to > > paravirtualized HW camera devices . > > > > Regarding the cameras, unfortunately same as above. > > Best regards, > Dmitry. > > > Regards, > > Saket Sinha > > > > On Mon, May 11, 2020 at 12:20 PM Keiichi Watanabe <keiichiw@xxxxxxxxxxxx> > wrote: > > > Hi Dmitry, > > > > > > On Mon, May 11, 2020 at 6:40 PM Dmitry Sepp <dmitry.sepp@xxxxxxxxxxxxxxx> > wrote: > > > > Hi Saket and all, > > > > > > > > As we are working with automotive platforms, unfortunately we don't plan > > > > any Qemu reference implementation so far. > > > > > > > > Of course we are ready to support the community if any help is needed. > > > > Is > > > > there interest in support for the FWHT format only for testing purpose > > > > or you want a full-featured implementation on the QEMU side? > > > > > > I guess we don't need to implement the codec algorithm in QEMU. > > > Rather, QEMU forwards virtio-video requests to the host video device > > > or a software library such as GStreamer or ffmpeg. > > > So, what we need to implement in QEMU is a kind of API translation, > > > which shouldn't care about actual video formats so much. > > > > > > Regarding the FWHT format discussed in the patch thread [1], in my > > > understanding, Hans suggested to have QEMU implementation forwarding > > > requests to the host's vicodec module [2]. > > > Then, we'll be able to test the virtio-video driver on QEMU on Linux > > > even if the host Linux has no hardware video decoder. > > > (Please correct me if I'm wrong.) > > > > > > Let me add Hans and Linux media ML in CC. > > > > > > [1] https://patchwork.linuxtv.org/patch/61717/ > > > [2] https://lwn.net/Articles/760650/ > > > > > > Best regards, > > > Keiichi > > > > > > > Please note that the spec is not finalized yet and a major update is now > > > > discussed with upstream and the Chrome OS team, which is also interested > > > > and deeply involved in the process. The update mostly implies some > > > > rewording and reorganization of data structures, but for sure will > > > > require a driver rework. > > > > > > > > Best regards, > > > > Dmitry. > > > > > > > > On Samstag, 9. Mai 2020 16:11:43 CEST Saket Sinha wrote: > > > > > Hi, > > > > > > > > > > As suggested on #qemu-devel IRC channel, I am including virtio-dev, > > > > > Gerd and Michael to point in the right direction how to move forward > > > > > with Qemu support for Virtio Video V4L2 driver > > > > > posted in [1]. > > > > > > > > > > [1]: https://patchwork.linuxtv.org/patch/61717/ > > > > > > > > > > Regards, > > > > > Saket Sinha > > > > > > > > > > On Sat, May 9, 2020 at 1:09 AM Saket Sinha <saket.sinha89@xxxxxxxxx> > wrote: > > > > > > Hi , > > > > > > > > > > > > This is to inquire about Qemu support for Virtio Video V4L2 driver > > > > > > posted in [1]. > > > > > > I am currently not aware of any upstream effort for Qemu reference > > > > > > implementation and would like to discuss how to proceed with the > > > > > > same. > > > > > > > > > > > > [1]: https://patchwork.linuxtv.org/patch/61717/ > > > > > > > > > > > > Regards, > > > > > > Saket Sinha > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: virtio-dev-unsubscribe@xxxxxxxxxxxxxxxxxxxx > > > > For additional commands, e-mail: virtio-dev-help@xxxxxxxxxxxxxxxxxxxx >
