struct Frame {
uint8_t *data = nullptr;
uint8_t *data2 = nullptr; // Only if interleaved == true.
+ uint8_t *data_copy = nullptr; // Will get a non-interleaved copy if not nullptr.
size_t len = 0; // Number of bytes we actually have.
size_t size = 0; // Number of bytes we have room for.
size_t overflow = 0;
// if so, the frame in progress will be dropped.
virtual Frame alloc_frame() = 0;
+ // Similar to alloc_frame(), with two additional restrictions:
+ //
+ // - The width, height and stride given must be correct
+ // (can not be changed after the call).
+ // - create_frame(), unlike alloc_frame(), is allowed to sleep
+ // (so bmusb will never call it, but in Nageru, other producers
+ // might)
+ //
+ // These two restrictions are relevant for Nageru, since it means that
+ // it can make frame_copy point directly into a VA-API buffer to avoid
+ // an extra copy.
+ virtual Frame create_frame(size_t width, size_t height, size_t stride)
+ {
+ return alloc_frame();
+ }
+
virtual void release_frame(Frame frame) = 0;
};