On Sat July 28 2012 00:01:24 Sakari Ailus wrote: > Hi Prabhakar, > > Thanks for the patch, and my apologies for delayed answer! > > On Fri, Jul 27, 2012 at 04:25:04PM +0530, Prabhakar Lad wrote: > > From: Manjunath Hadli <manjunath.hadli@xxxxxx> > > > > add new enum entries for supporting the media-bus formats on dm365. > > These include some bayer and some non-bayer formats. > > V4L2_MBUS_FMT_YDYUYDYV8_1X16 and V4L2_MBUS_FMT_UV8_1X8 are used > > internal to the hardware by the resizer. > > V4L2_MBUS_FMT_SBGGR10_ALAW8_1X8 represents the bayer ALAW format > > that is supported by dm365 hardware. > > > > Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > > Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > Signed-off-by: Manjunath Hadli <manjunath.hadli@xxxxxx> > > Signed-off-by: Lad, Prabhakar <prabhakar.lad@xxxxxx> > > Cc: Sakari Ailus <sakari.ailus@xxxxxx> > > Cc: Guennadi Liakhovetski <g.liakhovetski@xxxxxx> > > --- > > Documentation/DocBook/media/v4l/subdev-formats.xml | 250 +++++++++++++++++++- > > include/linux/v4l2-mediabus.h | 10 +- > > 2 files changed, 252 insertions(+), 8 deletions(-) > > > > diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml b/Documentation/DocBook/media/v4l/subdev-formats.xml > > index 49c532e..75dc275 100644 > > --- a/Documentation/DocBook/media/v4l/subdev-formats.xml > > +++ b/Documentation/DocBook/media/v4l/subdev-formats.xml > > @@ -353,9 +353,9 @@ > > <listitem><para>The number of bits per pixel component. All components are > > transferred on the same number of bits. Common values are 8, 10 and 12.</para> > > </listitem> > > - <listitem><para>If the pixel components are DPCM-compressed, a mention of the > > - DPCM compression and the number of bits per compressed pixel component.</para> > > - </listitem> > > + <listitem><para>The compression (optional). If the pixel components are > > + ALAW- or DPCM-compressed, a mention of the compression scheme and the > > + number of bits per compressed pixel component.</para></listitem> > > <listitem><para>The number of bus samples per pixel. Pixels that are wider than > > the bus width must be transferred in multiple samples. Common values are > > 1 and 2.</para></listitem> > > @@ -504,6 +504,74 @@ > > <entry>r<subscript>1</subscript></entry> > > <entry>r<subscript>0</subscript></entry> > > </row> > > + <row id="V4L2-MBUS-FMT-SBGGR10-ALAW8-1X8"> > > + <entry>V4L2_MBUS_FMT_SBGGR10_ALAW8_1X8</entry> > > + <entry>0x3015</entry> > > + <entry></entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>b<subscript>7</subscript></entry> > > + <entry>b<subscript>6</subscript></entry> > > + <entry>b<subscript>5</subscript></entry> > > + <entry>b<subscript>4</subscript></entry> > > + <entry>b<subscript>3</subscript></entry> > > + <entry>b<subscript>2</subscript></entry> > > + <entry>b<subscript>1</subscript></entry> > > + <entry>b<subscript>0</subscript></entry> > > + </row> > > + <row id="V4L2-MBUS-FMT-SGBRG10-ALAW8-1X8"> > > + <entry>V4L2_MBUS_FMT_SGBRG10_ALAW8_1X8</entry> > > + <entry>0x3016</entry> > > + <entry></entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>g<subscript>7</subscript></entry> > > + <entry>g<subscript>6</subscript></entry> > > + <entry>g<subscript>5</subscript></entry> > > + <entry>g<subscript>4</subscript></entry> > > + <entry>g<subscript>3</subscript></entry> > > + <entry>g<subscript>2</subscript></entry> > > + <entry>g<subscript>1</subscript></entry> > > + <entry>g<subscript>0</subscript></entry> > > + </row> > > + <row id="V4L2-MBUS-FMT-SGRBG10-ALAW8-1X8"> > > + <entry>V4L2_MBUS_FMT_SGRBG10_ALAW8_1X8</entry> > > + <entry>0x3017</entry> > > + <entry></entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>g<subscript>7</subscript></entry> > > + <entry>g<subscript>6</subscript></entry> > > + <entry>g<subscript>5</subscript></entry> > > + <entry>g<subscript>4</subscript></entry> > > + <entry>g<subscript>3</subscript></entry> > > + <entry>g<subscript>2</subscript></entry> > > + <entry>g<subscript>1</subscript></entry> > > + <entry>g<subscript>0</subscript></entry> > > + </row> > > + <row id="V4L2-MBUS-FMT-SRGGB10-ALAW8-1X8"> > > + <entry>V4L2_MBUS_FMT_SRGGB10_ALAW8_1X8</entry> > > + <entry>0x3018</entry> > > + <entry></entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>-</entry> > > + <entry>r<subscript>7</subscript></entry> > > + <entry>r<subscript>6</subscript></entry> > > + <entry>r<subscript>5</subscript></entry> > > + <entry>r<subscript>4</subscript></entry> > > + <entry>r<subscript>3</subscript></entry> > > + <entry>r<subscript>2</subscript></entry> > > + <entry>r<subscript>1</subscript></entry> > > + <entry>r<subscript>0</subscript></entry> > > + </row> > > <row id="V4L2-MBUS-FMT-SBGGR10-DPCM8-1X8"> > > <entry>V4L2_MBUS_FMT_SBGGR10_DPCM8_1X8</entry> > > <entry>0x300b</entry> > > @@ -853,10 +921,16 @@ > > <title>Packed YUV Formats</title> > > > > <para>Those data formats transfer pixel data as (possibly downsampled) Y, U > > - and V components. The format code is made of the following information. > > + and V components. Some formats include dummy bits in some of their samples > > + and are collectively referred to as "YDYC" (Y-Dummy-Y-Chroma) formats. > > + One cannot rely on the values of these dummy bits as those are undefined. > > + </para> > > + <para>The format code is made of the following information. > > <itemizedlist> > > <listitem><para>The Y, U and V components order code, as transferred on the > > - bus. Possible values are YUYV, UYVY, YVYU and VYUY.</para></listitem> > > + bus. Possible values are YUYV, UYVY, YVYU and VYUY for formats with no > > + dummy bit, and YDYUYDYV, YDYVYDYU, YUYDYVYD and YVYDYUYD for YDYC formats. > > + </para></listitem> > > <listitem><para>The number of bits per pixel component. All components are > > transferred on the same number of bits. Common values are 8, 10 and 12.</para> > > </listitem> > > I dicussed dummy vs. padding (zeros) with Laurent and we concluded we should > use zero padding instead. The difference is that when processing the pixels > no extra operations are necessary to get rid of the dummy data when the > dummy bits are actually zero --- which in practice always is the case. > > I'm not aware of hardware that would assign padding bits (in this very > purpose) that are a part of writes the width of bus width something else > than zeros. It wouldn't make much sense either. > > So I suggest that dummy is replaced by padding which is defined to be zero. > > The letter in the format name could be 'Z', for example. > > Hans: what do you think? Bad idea. First of all, some hardware or FPGA can insert different values there. It's something that Cisco uses in some cases: it makes it easier to identify the dummy values if they have a non-zero fixed value. Another reason for not doing this is when such formats are used to display video: you don't want to force the software to fill in the dummy values with a specific value for no good reason. That would only cost extra CPU cycles. Regards, Hans > > Kind regards, > > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
