media: videodev2.h: add V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM

Add an enum_fmt format flag to specifically tag coded formats where
full bytestream parsing is supported by the device.

Some stateful decoders are capable of fully parsing a bytestream,
but others require that userspace pre-parses the bytestream into
frames or fields (see the corresponding pixelformat descriptions
for details).

If this flag is set, then this pre-parsing step is not required
(but still possible, of course).

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>

Documentation/media/uapi/v4l/vidioc-enum-fmt.rst

@@ -127,6 +127,14 @@ one until ``EINVAL`` is returned.
       - This format is not native to the device but emulated through
 	software (usually libv4l2), where possible try to use a native
 	format instead for better performance.
+    * - ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM``
+      - 0x0004
+      - The hardware decoder for this compressed bytestream format (aka coded
+	format) is capable of parsing a continuous bytestream. Applications do
+	not need to parse the bytestream themselves to find the boundaries
+	between frames/fields. This flag can only be used in combination with
+	the ``V4L2_FMT_FLAG_COMPRESSED`` flag, since this applies to compressed
+	formats only. This flag is valid for stateful decoders only.
 
 
 Return Value

Documentation/media/videodev2.h.rst.exceptions

@@ -180,6 +180,7 @@ replace define V4L2_PIX_FMT_FLAG_PREMUL_ALPHA reserved-formats
 # V4L2 format flags
 replace define V4L2_FMT_FLAG_COMPRESSED fmtdesc-flags
 replace define V4L2_FMT_FLAG_EMULATED fmtdesc-flags
+replace define V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM fmtdesc-flags
 
 # V4L2 timecode types
 replace define V4L2_TC_TYPE_24FPS timecode-type

include/uapi/linux/videodev2.h

@@ -774,8 +774,9 @@ struct v4l2_fmtdesc {
 	__u32		    reserved[4];
 };
 
-#define V4L2_FMT_FLAG_COMPRESSED 0x0001
-#define V4L2_FMT_FLAG_EMULATED   0x0002
+#define V4L2_FMT_FLAG_COMPRESSED		0x0001
+#define V4L2_FMT_FLAG_EMULATED			0x0002
+#define V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM	0x0004
 
 	/* Frame Size and frame rate enumeration */
 /*