AM57X: Sharing buffers between VPE, VENC and DRM

krishna chakravarthy raghu

Other Parts Discussed in Thread: AM5728

Hi,

We have a working V4L2 -> VPE - > VENC pipeline. We want to connect display to VPE output to enable user to preview video being encoded. We are trying to add Display (DRM) to output of VPE. To prevent a memcopy, we are trying to share buffers between VPE, VENC and DRM. To be able to do this I need to register buffer allocated by omap_bo_new with DRM.

(Please note using DRM buffers is not an option as display is optional in this use-case)

Will I be able to do this with drmModeAddFB2 API? If so is this demonstrated in any of the test applications. (Please note we are using custom framework and not Gstreamer)

Any help will be highly appreciated

Regards
Krishna

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

What processor is this?

0 krishna chakravarthy raghu over 8 years ago in reply to Biser Gatchev-XID

Prodigy 140 points

Hi,

I'm trying this on Sitara (AM5728) processor.

Regards,
Krishna

0 Manisha Agrawal over 8 years ago in reply to krishna chakravarthy raghu

TI__Mastermind 22386 points

Check below file in git repo. It is dual camera demo example code on AM437x but can be applicable to AM57x processor as underneath software remain same. Hope this helps.
git.ti.com/.../loopback.c

0 krishna chakravarthy raghu over 8 years ago in reply to Manisha Agrawal

Prodigy 140 points

Hi,

Thanks for the reply.

Demo code uses buffers allocated with call omap_bo_new using DRM.

I do not want to do that. I want to allocate buffers for VENC, and reuse the same buffers as frame buffers for DRM.

Is that possible? if yes, how to do that?

Regards,

Krishna

0 krishna chakravarthy raghu over 8 years ago in reply to krishna chakravarthy raghu

Prodigy 140 points

Just a clarification.
By saying allocating buffers for VENC, I mean using DCE to allocate buffers.
I want to use DCE buffers as frame buffers for DRM.

0 Manisha Agrawal over 8 years ago in reply to krishna chakravarthy raghu

TI__Mastermind 22386 points

Currently the omapdrm only supports dmabuf export feature. The feature that you are looking is dmabuf import. It is expected to be supported in SDK 2.02 release in March, 2016.

0 krishna chakravarthy raghu over 8 years ago in reply to Manisha Agrawal

Prodigy 140 points

Thanks for the update.

0 krishna chakravarthy raghu over 7 years ago in reply to krishna chakravarthy raghu

Prodigy 140 points

Hi,

Does omapdrm support dmabuf import feature in PSDK release 02.00.02?

Regards,
Krishna

0 Manisha Agrawal over 7 years ago in reply to krishna chakravarthy raghu

TI__Mastermind 22386 points

Yes

0 krishna chakravarthy raghu over 7 years ago in reply to Manisha Agrawal

Prodigy 140 points

Hi,

Thanks for the reply.

We are trying to export buffers from DCE.
But the export ioctl requires DCE file descriptor as one of it's input arguments.
The dce_init() call returns DCE handle and not file descriptor.
Can you let us know how to get DCE file descriptor from DCE handle?

Regards,
Krishna

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AM57X: Sharing buffers between VPE, VENC and DRM