[PATCH v10 3/4] media: pixfmt: Add H264_SLICE_RAW format documentation

From: Paul Kocialkowski
Date: Wed Apr 24 2019 - 10:23:48 EST


From: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>

The H264_SLICE_RAW format introduced before is meant for stateless
decoders that will need the H264 parsed slice data without the start code.

Let's document it.

Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
---
.../media/uapi/v4l/pixfmt-compressed.rst | 25 +++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/Documentation/media/uapi/v4l/pixfmt-compressed.rst b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
index 6c961cfb74da..4b701fc7653e 100644
--- a/Documentation/media/uapi/v4l/pixfmt-compressed.rst
+++ b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
@@ -52,6 +52,31 @@ Compressed Formats
- ``V4L2_PIX_FMT_H264_MVC``
- 'M264'
- H264 MVC video elementary stream.
+ * .. _V4L2-PIX-FMT-H264-SLICE-RAW:
+
+ - ``V4L2_PIX_FMT_H264_SLICE_RAW``
+ - 'S264'
+ - H264 parsed slice data, without the start code and as
+ extracted from the H264 bitstream. This format is adapted for
+ stateless video decoders that implement an H264 pipeline
+ (using the :ref:`mem2mem` and :ref:`media-request-api`).
+ Metadata associated with the frame to decode are required to
+ be passed through the ``V4L2_CID_MPEG_VIDEO_H264_SPS``,
+ ``V4L2_CID_MPEG_VIDEO_H264_PPS``,
+ ``V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX``,
+ ``V4L2_CID_MPEG_VIDEO_H264_SLICE_PARAMS`` and
+ ``V4L2_CID_MPEG_VIDEO_H264_DECODE_PARAMS`` controls. See the
+ :ref:`associated Codec Control IDs <v4l2-mpeg-h264>`. Exactly
+ one output and one capture buffer must be provided for use
+ with this pixel format. The output buffer must contain the
+ appropriate number of macroblocks to decode a full
+ corresponding frame to the matching capture buffer.
+
+ .. note::
+
+ This format is not yet part of the public kernel API and it
+ is expected to change.
+
* .. _V4L2-PIX-FMT-H263:

- ``V4L2_PIX_FMT_H263``
--
2.21.0