On Thu, Aug 15, 2019 at 5:11 PM Alexandre Courbot <acourbot@xxxxxxxxxxxx> wrote:
>
> On Mon, Aug 12, 2019 at 8:05 PM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote:
> >
> > 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).
>
> Reviewed-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
>
> This patch does not update the pixelformat descriptions though, are we
> planning on doing this?
I pressed Send too fast, patch 8 takes care of this. Sorry for the noise.
>
>
> >
> > 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@xxxxxxxxx>
> > ---
> > Documentation/media/uapi/v4l/vidioc-enum-fmt.rst | 8 ++++++++
> > Documentation/media/videodev2.h.rst.exceptions | 1 +
> > include/uapi/linux/videodev2.h | 5 +++--
> > 3 files changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > index 822d6730e7d2..ebc05ce74bdf 100644
> > --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > +++ b/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
> > diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
> > index 8e7d3492d248..a0640b6d0f68 100644
> > --- a/Documentation/media/videodev2.h.rst.exceptions
> > +++ b/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
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index 2427bc4d8eba..67077d52c59d 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/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 */
> > /*
> > --
> > 2.20.1
> >
