h264: use v4l2_get_controls to query decode mode and start code

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

src/context.c

@@ -105,6 +105,8 @@ VAStatus RequestCreateContext(VADriverContextP context, VAConfigID config_id,
 	case VAProfileH264MultiviewHigh:
 	case VAProfileH264StereoHigh:
 		pixelformat = V4L2_PIX_FMT_H264_SLICE;
+		/* Query decode mode and start code */
+		h264_get_controls(driver_data, context_object);
 		break;
 
 	case VAProfileHEVCMain:

src/context.h

@@ -50,6 +50,7 @@ struct object_context {
 
 	/* H264 only */
 	struct h264_dpb dpb;
+	bool h264_start_code;
 };
 
 VAStatus RequestCreateContext(VADriverContextP context, VAConfigID config_id,

src/h264.c

@@ -405,6 +405,46 @@ static void h264_va_slice_to_v4l2(struct request_data *driver_data,
 				     VASlice->chroma_offset_l1);
 }
 
+int h264_get_controls(struct request_data *driver_data,
+		      struct object_context *context)
+{
+	struct v4l2_ext_control controls[2] = {
+		{
+			.id = V4L2_CID_MPEG_VIDEO_H264_DECODE_MODE,
+		}, {
+			.id = V4L2_CID_MPEG_VIDEO_H264_START_CODE,
+		}
+	};
+	int rc;
+
+	rc = v4l2_get_controls(driver_data->video_fd, -1, controls, 2);
+	if (rc < 0)
+		return VA_STATUS_ERROR_OPERATION_FAILED;
+
+	switch (controls[0].value) {
+	case V4L2_MPEG_VIDEO_H264_DECODE_MODE_SLICE_BASED:
+		break;
+	case V4L2_MPEG_VIDEO_H264_DECODE_MODE_FRAME_BASED:
+		break;
+	default:
+		request_log("Unsupported decode mode\n");
+		return VA_STATUS_ERROR_OPERATION_FAILED;
+	}
+
+	switch (controls[1].value) {
+	case V4L2_MPEG_VIDEO_H264_START_CODE_NONE:
+		break;
+	case V4L2_MPEG_VIDEO_H264_START_CODE_ANNEX_B:
+		context->h264_start_code = true;
+		break;
+	default:
+		request_log("Unsupported start code\n");
+		return VA_STATUS_ERROR_OPERATION_FAILED;
+	}
+
+	return VA_STATUS_SUCCESS;
+}
+
 int h264_set_controls(struct request_data *driver_data,
 		      struct object_context *context,
 		      struct object_surface *surface)

src/h264.h

@@ -51,6 +51,8 @@ struct h264_dpb {
 	unsigned int age;
 };
 
+int h264_get_controls(struct request_data *driver_data,
+		      struct object_context *context);
 int h264_set_controls(struct request_data *data,
 		      struct object_context *context,
 		      struct object_surface *surface);