Need API to know allocated buffers from upstream
Submitted by Guillaume Desmottes @gdesmott
Link to original bug (#783085)
Description
We are working on implementing DMA support in gst-omx. When acting as a DMA importer, an element needs to know beforehand which buffers have been allocated upstream so it can call OMX_UseBuffer() on each allocated buffer it's going to use.
We currently solved this using a custom downstream event sent in gst_v4l2src_decide_allocation() but it would be good to have a proper solution for this.
We could add a "allocated-buffers" serialized downstream event which is sent when buffers are (re)allocated before starting to use them.
It would include a GPtrArray of GstBuffers.
We should probably be clear in the doc on what can and cannot be done with those buffers. Something like "Those buffers should not be modified in anyway."
Thoughts?