media: v4l2-mem2mem: add v4l2_m2m_buf_copy_data helper function

Memory-to-memory devices should copy various parts of
struct v4l2_buffer from the output buffer to the capture buffer.

Add a helper function that does that to simplify the driver code.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/v4l2-core/v4l2-mem2mem.c

@@ -975,6 +975,26 @@ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
 }
 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 
+void v4l2_m2m_buf_copy_data(const struct vb2_v4l2_buffer *out_vb,
+			    struct vb2_v4l2_buffer *cap_vb,
+			    bool copy_frame_flags)
+{
+	u32 mask = V4L2_BUF_FLAG_TIMECODE | V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
+
+	if (copy_frame_flags)
+		mask |= V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_PFRAME |
+			V4L2_BUF_FLAG_BFRAME;
+
+	cap_vb->vb2_buf.timestamp = out_vb->vb2_buf.timestamp;
+
+	if (out_vb->flags & V4L2_BUF_FLAG_TIMECODE)
+		cap_vb->timecode = out_vb->timecode;
+	cap_vb->field = out_vb->field;
+	cap_vb->flags &= ~mask;
+	cap_vb->flags |= out_vb->flags & mask;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_buf_copy_data);
+
 void v4l2_m2m_request_queue(struct media_request *req)
 {
 	struct media_request_object *obj, *obj_safe;

include/media/v4l2-mem2mem.h

@@ -622,6 +622,26 @@ v4l2_m2m_dst_buf_remove_by_idx(struct v4l2_m2m_ctx *m2m_ctx, unsigned int idx)
 	return v4l2_m2m_buf_remove_by_idx(&m2m_ctx->cap_q_ctx, idx);
 }
 
+/**
+ * v4l2_m2m_buf_copy_data() - copy buffer data from the output buffer to the
+ * capture buffer
+ *
+ * @out_vb: the output buffer that is the source of the data.
+ * @cap_vb: the capture buffer that will receive the data.
+ * @copy_frame_flags: copy the KEY/B/PFRAME flags as well.
+ *
+ * This helper function copies the timestamp, timecode (if the TIMECODE
+ * buffer flag was set), field and the TIMECODE, KEYFRAME, BFRAME, PFRAME
+ * and TSTAMP_SRC_MASK flags from @out_vb to @cap_vb.
+ *
+ * If @copy_frame_flags is false, then the KEYFRAME, BFRAME and PFRAME
+ * flags are not copied. This is typically needed for encoders that
+ * set this bits explicitly.
+ */
+void v4l2_m2m_buf_copy_data(const struct vb2_v4l2_buffer *out_vb,
+			    struct vb2_v4l2_buffer *cap_vb,
+			    bool copy_frame_flags);
+
 /* v4l2 request helper */
 
 void v4l2_m2m_request_queue(struct media_request *req);