RE: [RFC/PATCH v7 1/5] Changes in include/linux/videodev2.h for MFC 5.1

[Jaeryul Oh <jaeryul.oh@samsung.com>]

Hi, I commented as below.

> -----Original Message-----
> From: Kamil Debski [mailto:k.debski@samsung.com]
> Sent: Saturday, March 05, 2011 3:57 AM
> To: 'Laurent Pinchart'
> Cc: linux-media@vger.kernel.org; linux-samsung-soc@vger.kernel.org; Marek
> Szyprowski; kyungmin.park@samsung.com; jaeryul.oh@samsung.com;
> kgene.kim@samsung.com
> Subject: RE: [RFC/PATCH v7 1/5] Changes in include/linux/videodev2.h for
> MFC 5.1
> 
> Hi,
> 
> > -----Original Message-----
> > From: Laurent Pinchart [mailto:laurent.pinchart@ideasonboard.com]
> > Sent: 04 March 2011 17:39
> > To: Kamil Debski
> > Cc: linux-media@vger.kernel.org; linux-samsung-soc@vger.kernel.org;
> > m.szyprowski@samsung.com; kyungmin.park@samsung.com;
> > jaeryul.oh@samsung.com; kgene.kim@samsung.com
> > Subject: Re: [RFC/PATCH v7 1/5] Changes in include/linux/videodev2.h
> > for MFC 5.1
> >
> > On Friday 04 March 2011 12:26:18 Kamil Debski wrote:
> > > This patch adds fourcc values for compressed video stream formats and
> > > V4L2_CTRL_CLASS_CODEC. Also adds controls used by MFC 5.1 driver.
> > >
> > > Signed-off-by: Kamil Debski <k.debski@samsung.com>
> > > Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> > > ---
> > >  include/linux/videodev2.h |   39
> > +++++++++++++++++++++++++++++++++++++++
> > >  1 files changed, 39 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> > > index a94c4d5..a48a42e 100644
> > > --- a/include/linux/videodev2.h
> > > +++ b/include/linux/videodev2.h
> > > @@ -369,6 +369,19 @@ struct v4l2_pix_format {
> > >  #define V4L2_PIX_FMT_DV       v4l2_fourcc('d', 'v', 's', 'd') /*
> > 1394 */
> > >  #define V4L2_PIX_FMT_MPEG     v4l2_fourcc('M', 'P', 'E', 'G') /*
> > MPEG-1/2/4 */
> > >
> > > +#define V4L2_PIX_FMT_H264     v4l2_fourcc('H', '2', '6', '4') /*
> > H264 */
> > > +#define V4L2_PIX_FMT_H263     v4l2_fourcc('H', '2', '6', '3') /*
> > H263 */
> > > +#define V4L2_PIX_FMT_MPEG12   v4l2_fourcc('M', 'P', '1', '2') /*
> > MPEG-1/2  */
> > > +#define V4L2_PIX_FMT_MPEG4    v4l2_fourcc('M', 'P', 'G', '4') /*
> > MPEG-4  */
> > > +#define V4L2_PIX_FMT_DIVX     v4l2_fourcc('D', 'I', 'V', 'X') /*
> > DivX  */
> > > +#define V4L2_PIX_FMT_DIVX3    v4l2_fourcc('D', 'I', 'V', '3') /*
> > DivX 3.11 */
> > > +#define V4L2_PIX_FMT_DIVX4    v4l2_fourcc('D', 'I', 'V', '4') /*
> > DivX 4.12 */
> > > +#define V4L2_PIX_FMT_DIVX500  v4l2_fourcc('D', 'X', '5', '2') /*
> > DivX 5.00 - 5.02 */
> > > +#define V4L2_PIX_FMT_DIVX503  v4l2_fourcc('D', 'X', '5', '3') /*
> > DivX 5.03 - x */
> > > +#define V4L2_PIX_FMT_XVID     v4l2_fourcc('X', 'V', 'I', 'D') /*
> > Xvid */
> > > +#define V4L2_PIX_FMT_VC1      v4l2_fourcc('V', 'C', '1', 'A') /* VC-
> > 1 */
> > > +#define V4L2_PIX_FMT_VC1_RCV  v4l2_fourcc('V', 'C', '1', 'R') /* VC-
> > 1 RCV */
> > > +
> >
> > Hans, you mentioned some time ago that you were against ading H.264 or
> > MPEG4
> > fourccs, and that drivers should use the MPEG controls instead. Could
> > you
> > clarify your current position on this ?
> 
> If I remember correct there was no clear conclusion on this. I hope we can
> discuss this
> during the upcoming meeting.
> 
> Have you got an alternative suggestion to using fourccs?
> 
> The existing MPEG controls won't cover all the functions and parameters
> that
> are
> used by video codecs. The controls that are in this patch are the ones
> related to
> decoding, there is even more for encoding.
> 
> Yesterday I have been talking with Hans on the IRC channel about the
> control
> for
> quantization parameters and he has suggested to use different for MPEG4,
> H263 and H264.
> Personally I'd like to have a common one, as the QP meaning is the same in
> those 3
> cases, the difference is the range of the value.
> So I think that this still is a subject that could use more discussion as
> there are
> a few ideas.
According to the fource.org, and if fourcc definition here has been made
from fourcc.org,
We need to have a discussion about new types that Kamil added not only h264
but divx_xxx.
QP might be a same topic. So let's discuss more at Poland meeting.
> 
> Best regards,
> 
> --
> Kamil Debski
> Linux Platform Group
> Samsung Poland R&D Center