Gstreamer zero copy dmabuf encoding

Question

I want to encode a framebuffer I got via dmabuf into a video stream.

I have a dmabuf file descriptor which contains the framebuffer. I got the filedescriptor from the intel i915 driver via ioctl VFIO_DEVICE_QUERY_GFX_PLANE. Now I want to encode it per zero copy in gstreamer into a video stream (h264, h265 etc...). I push the single frames per appsrc into the gstreamer pipline. Since I use intel hardware I thought it makes sense to use VAAPI.

The problem is that the sink pads of vaapi only support video/x-raw and video/x-raw(memory:VASurface) and I have video/x-raw(memory:DMABuf).

Is there any way to convert video/x-raw(memory:DMABuf) to video/x-raw(memory:VASurface) (zero copy) or import the DMABuf directly as video/x-raw(memory:VASurface)?

Alternatively is there a framework which is better suited than vaapi?

My code to push the frames into gstreamer currently looks like this:

    GstMemory* mem = gst_dmabuf_allocator_alloc(vedpy->gdata.allocator, dmabuf->fd, dmabuf->width * dmabuf->height * (dmabuf->stride/1024));
    vedpy->gdata.buffer = gst_buffer_new();
    gst_buffer_append_memory(vedpy->gdata.buffer, mem );
    
    gsize offset[GST_VIDEO_MAX_PLANES] = {0, 0, 0, 0};
    gint stride[GST_VIDEO_MAX_PLANES] = {dmabuf->stride, 0, 0, 0};
    gst_buffer_add_video_meta_full( vedpy->gdata.buffer, GST_VIDEO_FRAME_FLAG_NONE,
                                    GST_VIDEO_FORMAT_ENCODED,
                                    dmabuf->width, dmabuf->height, 1, offset, stride);
    GstFlowReturn ret;
    vfio_encode_dpy *vedpy = container_of(dcl, vfio_encode_dpy, dcl);
    g_signal_emit_by_name (vedpy->gdata.source, "push-buffer", vedpy->gdata.buffer, &ret);

And my pipline:

char launch_stream[]  = "appsrc name=source ! "
    " video/x-raw(memory:DMABuf),width=1024,height=768,framerate=0/1,format={BGRx,BGRx:0x0100000000000001} ! "
    " vaapipostproc !"
    " vaapih265enc ! 
    ...

which obviously does not work, because vaapipostproc can not be linked with the filter.

Gstreamer zero copy dmabuf encoding

0 Answers0