Re: [PATCH 2/3] Document 8-bit and 16-bit YCrCb media bus pixel codes
Hi Christian, On Wednesday 13 July 2011 20:58:12 Christian Gmeiner wrote: 2011/7/11 Christian Gmeiner christian.gmei...@gmail.com: 2011/7/11 Laurent Pinchart laurent.pinch...@ideasonboard.com: On Sunday 10 July 2011 20:14:21 Christian Gmeiner wrote: Signed-off-by: Christian Gmeiner --- diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml b/Documentation/DocBook/media/v4l/subdev-formats.xml index 49c532e..18e30b0 100644 --- a/Documentation/DocBook/media/v4l/subdev-formats.xml +++ b/Documentation/DocBook/media/v4l/subdev-formats.xml @@ -2565,5 +2565,43 @@ /tgroup /table /section + +section + titleYCrCb Formats/title + + paraYCbCr represents colors as a combination of three values: + itemizedlist + listitemparaY - the luminosity (roughly the brightness)/para/listitem + listitemparaCb - the chrominance of the blue primary/para/listitem + listitemparaCr - the chrominance of the red primary/para/listitem How does that differ from YUV ? I need to say that I am very new to this whole format stuff and so I am not really sure. In the data sheet http://dxr3.sourceforge.net/download/hardware/ADV7175A_6A.pdf there is on the first page a FUNCTIONAL BLOCK DIAGRAM which shows that there is a YCrCb to YUV Matrix stage in the pipeline. I am also fine to use a YUV format for the media bus. Any suggestions? Okay I think I have found the difference between YUV and YCrCb - see [1] YCbCr 4:2:2 (Redirected from YUV 4:2:2) FourCCs: YUY2, UYVY, YUV2 (Apple Component Video stored in MOV files) Samples: http://samples.mplayerhq.hu/V-codecs/YUV2/ (These FourCC names only reflect that the YCbCr of digital media is often falsely mixed up with analog PAL's YUV color space.) YCbCr 4:2:2 is a packed YCbCr format in which a pair of consecutive pixels is represented by 1 Y sample each but share a Cb sample and a Cr sample. This type of data may be packaged in a container format with a a FourCC of YUY2 which indicates the following byte formatting: [1] http://wiki.multimedia.cx/index.php?title=YUV_4:2:2 According to http://en.wikipedia.org/wiki/Yuv, Historically, the terms YUV and Y'UV were used for a specific analog encoding of color information in television systems, while YCbCr was used for digital encoding of color information suited for video and still-image compression and transmission such as MPEG and JPEG. Today, the term YUV is commonly used in the computer industry to describe file-formats that are encoded using YCbCr. V4L2 seems to suffer from the ambiguity, as we use YUV as generic term to mean a digital luma/chroma format. I thus think your driver should use the existing YUV pixel codes. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/3] Document 8-bit and 16-bit YCrCb media bus pixel codes
2011/7/11 Christian Gmeiner christian.gmei...@gmail.com: Hi Laurent, 2011/7/11 Laurent Pinchart laurent.pinch...@ideasonboard.com: Hi Christian, On Sunday 10 July 2011 20:14:21 Christian Gmeiner wrote: Signed-off-by: Christian Gmeiner --- diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml b/Documentation/DocBook/media/v4l/subdev-formats.xml index 49c532e..18e30b0 100644 --- a/Documentation/DocBook/media/v4l/subdev-formats.xml +++ b/Documentation/DocBook/media/v4l/subdev-formats.xml @@ -2565,5 +2565,43 @@ /tgroup /table /section + + section + titleYCrCb Formats/title + + paraYCbCr represents colors as a combination of three values: + itemizedlist + listitemparaY - the luminosity (roughly the brightness)/para/listitem + listitemparaCb - the chrominance of the blue primary/para/listitem + listitemparaCr - the chrominance of the red primary/para/listitem How does that differ from YUV ? I need to say that I am very new to this whole format stuff and so I am not really sure. In the data sheet http://dxr3.sourceforge.net/download/hardware/ADV7175A_6A.pdf there is on the first page a FUNCTIONAL BLOCK DIAGRAM which shows that there is a YCrCb to YUV Matrix stage in the pipeline. I am also fine to use a YUV format for the media bus. Any suggestions? Okay I think I have found the difference between YUV and YCrCb - see [1] YCbCr 4:2:2 (Redirected from YUV 4:2:2) FourCCs: YUY2, UYVY, YUV2 (Apple Component Video stored in MOV files) Samples: http://samples.mplayerhq.hu/V-codecs/YUV2/ (These FourCC names only reflect that the YCbCr of digital media is often falsely mixed up with analog PAL's YUV color space.) YCbCr 4:2:2 is a packed YCbCr format in which a pair of consecutive pixels is represented by 1 Y sample each but share a Cb sample and a Cr sample. This type of data may be packaged in a container format with a a FourCC of YUY2 which indicates the following byte formatting: [1] http://wiki.multimedia.cx/index.php?title=YUV_4:2:2 Greets, -- Christian Gmeiner, MSc -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/3] Document 8-bit and 16-bit YCrCb media bus pixel codes
Hi Christian, On Sunday 10 July 2011 20:14:21 Christian Gmeiner wrote: Signed-off-by: Christian Gmeiner --- diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml b/Documentation/DocBook/media/v4l/subdev-formats.xml index 49c532e..18e30b0 100644 --- a/Documentation/DocBook/media/v4l/subdev-formats.xml +++ b/Documentation/DocBook/media/v4l/subdev-formats.xml @@ -2565,5 +2565,43 @@ /tgroup /table /section + +section + titleYCrCb Formats/title + + paraYCbCr represents colors as a combination of three values: + itemizedlist + listitemparaY - the luminosity (roughly the brightness)/para/listitem + listitemparaCb - the chrominance of the blue primary/para/listitem + listitemparaCr - the chrominance of the red primary/para/listitem How does that differ from YUV ? + /itemizedlist + /para + + paraThe following table lists existing YCrCb compressed formats./para + + table pgwide=0 frame=none id=v4l2-mbus-pixelcode-ycrcb + titleYCrCb Formats/title + tgroup cols=2 + colspec colname=id align=left / + colspec colname=code align=left/ + thead + row + entryIdentifier/entry + entryCode/entry + /row + /thead + tbody valign=top + row id=V4L2_MBUS_FMT_YCRCB_1X8 + entryV4L2_MBUS_FMT_YCRCB_1X8/entry + entry0x5001/entry + /row + row id=V4L2_MBUS_FMT_YCRCB_1X16 + entryV4L2_MBUS_FMT_YCRCB_1X16/entry + entry0x5002/entry + /row + /tbody + /tgroup + /table +/section /section /section -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/3] Document 8-bit and 16-bit YCrCb media bus pixel codes
Hi Laurent, 2011/7/11 Laurent Pinchart laurent.pinch...@ideasonboard.com: Hi Christian, On Sunday 10 July 2011 20:14:21 Christian Gmeiner wrote: Signed-off-by: Christian Gmeiner --- diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml b/Documentation/DocBook/media/v4l/subdev-formats.xml index 49c532e..18e30b0 100644 --- a/Documentation/DocBook/media/v4l/subdev-formats.xml +++ b/Documentation/DocBook/media/v4l/subdev-formats.xml @@ -2565,5 +2565,43 @@ /tgroup /table /section + + section + titleYCrCb Formats/title + + paraYCbCr represents colors as a combination of three values: + itemizedlist + listitemparaY - the luminosity (roughly the brightness)/para/listitem + listitemparaCb - the chrominance of the blue primary/para/listitem + listitemparaCr - the chrominance of the red primary/para/listitem How does that differ from YUV ? I need to say that I am very new to this whole format stuff and so I am not really sure. In the data sheet http://dxr3.sourceforge.net/download/hardware/ADV7175A_6A.pdf there is on the first page a FUNCTIONAL BLOCK DIAGRAM which shows that there is a YCrCb to YUV Matrix stage in the pipeline. I am also fine to use a YUV format for the media bus. Any suggestions? Greets, -- Christian Gmeiner, MSc -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 2/3] Document 8-bit and 16-bit YCrCb media bus pixel codes
Signed-off-by: Christian Gmeiner --- diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml b/Documentation/DocBook/media/v4l/subdev-formats.xml index 49c532e..18e30b0 100644 --- a/Documentation/DocBook/media/v4l/subdev-formats.xml +++ b/Documentation/DocBook/media/v4l/subdev-formats.xml @@ -2565,5 +2565,43 @@ /tgroup /table /section + +section + titleYCrCb Formats/title + + paraYCbCr represents colors as a combination of three values: + itemizedlist + listitemparaY - the luminosity (roughly the brightness)/para/listitem + listitemparaCb - the chrominance of the blue primary/para/listitem + listitemparaCr - the chrominance of the red primary/para/listitem + /itemizedlist + /para + + paraThe following table lists existing YCrCb compressed formats./para + + table pgwide=0 frame=none id=v4l2-mbus-pixelcode-ycrcb + titleYCrCb Formats/title + tgroup cols=2 + colspec colname=id align=left / + colspec colname=code align=left/ + thead + row + entryIdentifier/entry + entryCode/entry + /row + /thead + tbody valign=top + row id=V4L2_MBUS_FMT_YCRCB_1X8 + entryV4L2_MBUS_FMT_YCRCB_1X8/entry + entry0x5001/entry + /row + row id=V4L2_MBUS_FMT_YCRCB_1X16 + entryV4L2_MBUS_FMT_YCRCB_1X16/entry + entry0x5002/entry + /row + /tbody + /tgroup + /table +/section /section /section -- 1.7.6 -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
