diff options
Diffstat (limited to 'kernel/Documentation/DocBook/media/v4l/pixfmt.xml')
| -rw-r--r-- | kernel/Documentation/DocBook/media/v4l/pixfmt.xml | 245 |
1 files changed, 218 insertions, 27 deletions
diff --git a/kernel/Documentation/DocBook/media/v4l/pixfmt.xml b/kernel/Documentation/DocBook/media/v4l/pixfmt.xml index fcde4e202..d871245d2 100644 --- a/kernel/Documentation/DocBook/media/v4l/pixfmt.xml +++ b/kernel/Documentation/DocBook/media/v4l/pixfmt.xml @@ -157,6 +157,14 @@ see <xref linkend="colorspaces" />.</entry> capture streams and by the application for output streams, see <xref linkend="colorspaces" />.</entry> </row> + <row> + <entry>&v4l2-xfer-func;</entry> + <entry><structfield>xfer_func</structfield></entry> + <entry>This information supplements the +<structfield>colorspace</structfield> and must be set by the driver for +capture streams and by the application for output streams, +see <xref linkend="colorspaces" />.</entry> + </row> </tbody> </tgroup> </table> @@ -190,8 +198,8 @@ see <xref linkend="colorspaces" />.</entry> <row> <entry>__u16</entry> <entry><structfield>reserved[6]</structfield></entry> - <entry>Reserved for future extensions. Should be zeroed by the - application.</entry> + <entry>Reserved for future extensions. Should be zeroed by drivers and + applications.</entry> </row> </tbody> </tgroup> @@ -264,11 +272,19 @@ see <xref linkend="colorspaces" />.</entry> capture streams and by the application for output streams, see <xref linkend="colorspaces" />.</entry> </row> + <row> + <entry>&v4l2-xfer-func;</entry> + <entry><structfield>xfer_func</structfield></entry> + <entry>This information supplements the +<structfield>colorspace</structfield> and must be set by the driver for +capture streams and by the application for output streams, +see <xref linkend="colorspaces" />.</entry> + </row> <row> <entry>__u8</entry> - <entry><structfield>reserved[8]</structfield></entry> - <entry>Reserved for future extensions. Should be zeroed by the - application.</entry> + <entry><structfield>reserved[7]</structfield></entry> + <entry>Reserved for future extensions. Should be zeroed by drivers + and applications.</entry> </row> </tbody> </tgroup> @@ -476,15 +492,16 @@ is also very useful.</para> <section> <title>Defining Colorspaces in V4L2</title> - <para>In V4L2 colorspaces are defined by three values. The first is the colorspace -identifier (&v4l2-colorspace;) which defines the chromaticities, the transfer + <para>In V4L2 colorspaces are defined by four values. The first is the colorspace +identifier (&v4l2-colorspace;) which defines the chromaticities, the default transfer function, the default Y'CbCr encoding and the default quantization method. The second -is the Y'CbCr encoding identifier (&v4l2-ycbcr-encoding;) to specify non-standard -Y'CbCr encodings and the third is the quantization identifier (&v4l2-quantization;) -to specify non-standard quantization methods. Most of the time only the colorspace -field of &v4l2-pix-format; or &v4l2-pix-format-mplane; needs to be filled in. Note -that the default R'G'B' quantization is full range for all colorspaces except for -BT.2020 which uses limited range R'G'B' quantization.</para> +is the transfer function identifier (&v4l2-xfer-func;) to specify non-standard +transfer functions. The third is the Y'CbCr encoding identifier (&v4l2-ycbcr-encoding;) +to specify non-standard Y'CbCr encodings and the fourth is the quantization identifier +(&v4l2-quantization;) to specify non-standard quantization methods. Most of the time +only the colorspace field of &v4l2-pix-format; or &v4l2-pix-format-mplane; needs to +be filled in. Note that the default R'G'B' quantization is full range for all +colorspaces except for BT.2020 which uses limited range R'G'B' quantization.</para> <table pgwide="1" frame="none" id="v4l2-colorspace"> <title>V4L2 Colorspaces</title> @@ -498,6 +515,11 @@ BT.2020 which uses limited range R'G'B' quantization.</para> </thead> <tbody valign="top"> <row> + <entry><constant>V4L2_COLORSPACE_DEFAULT</constant></entry> + <entry>The default colorspace. This can be used by applications to let the + driver fill in the colorspace.</entry> + </row> + <row> <entry><constant>V4L2_COLORSPACE_SMPTE170M</constant></entry> <entry>See <xref linkend="col-smpte-170m" />.</entry> </row> @@ -518,6 +540,10 @@ BT.2020 which uses limited range R'G'B' quantization.</para> <entry>See <xref linkend="col-bt2020" />.</entry> </row> <row> + <entry><constant>V4L2_COLORSPACE_DCI_P3</constant></entry> + <entry>See <xref linkend="col-dcip3" />.</entry> + </row> + <row> <entry><constant>V4L2_COLORSPACE_SMPTE240M</constant></entry> <entry>See <xref linkend="col-smpte-240m" />.</entry> </row> @@ -533,6 +559,60 @@ BT.2020 which uses limited range R'G'B' quantization.</para> <entry><constant>V4L2_COLORSPACE_JPEG</constant></entry> <entry>See <xref linkend="col-jpeg" />.</entry> </row> + <row> + <entry><constant>V4L2_COLORSPACE_RAW</constant></entry> + <entry>The raw colorspace. This is used for raw image capture where + the image is minimally processed and is using the internal colorspace + of the device. The software that processes an image using this + 'colorspace' will have to know the internals of the capture device.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="v4l2-xfer-func"> + <title>V4L2 Transfer Function</title> + <tgroup cols="2" align="left"> + &cs-def; + <thead> + <row> + <entry>Identifier</entry> + <entry>Details</entry> + </row> + </thead> + <tbody valign="top"> + <row> + <entry><constant>V4L2_XFER_FUNC_DEFAULT</constant></entry> + <entry>Use the default transfer function as defined by the colorspace.</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_709</constant></entry> + <entry>Use the Rec. 709 transfer function.</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_SRGB</constant></entry> + <entry>Use the sRGB transfer function.</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_ADOBERGB</constant></entry> + <entry>Use the AdobeRGB transfer function.</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_SMPTE240M</constant></entry> + <entry>Use the SMPTE 240M transfer function.</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_NONE</constant></entry> + <entry>Do not use a transfer function (i.e. use linear RGB values).</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_DCI_P3</constant></entry> + <entry>Use the DCI-P3 transfer function.</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_SMPTE2084</constant></entry> + <entry>Use the SMPTE 2084 transfer function.</entry> + </row> </tbody> </tgroup> </table> @@ -624,7 +704,8 @@ is mapped to [16…235]. Cb and Cr are mapped from [-0.5…0.5] to [16 <section id="col-smpte-170m"> <title>Colorspace SMPTE 170M (<constant>V4L2_COLORSPACE_SMPTE170M</constant>)</title> <para>The <xref linkend="smpte170m" /> standard defines the colorspace used by NTSC and PAL and by SDTV -in general. The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_601</constant>. +in general. The default transfer function is <constant>V4L2_XFER_FUNC_709</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_601</constant>. The default Y'CbCr quantization is limited range. The chromaticities of the primary colors and the white reference are:</para> <table frame="none"> @@ -706,7 +787,8 @@ rarely seen.</para> <section id="col-rec709"> <title>Colorspace Rec. 709 (<constant>V4L2_COLORSPACE_REC709</constant>)</title> - <para>The <xref linkend="itu709" /> standard defines the colorspace used by HDTV in general. The default + <para>The <xref linkend="itu709" /> standard defines the colorspace used by HDTV in general. +The default transfer function is <constant>V4L2_XFER_FUNC_709</constant>. The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_709</constant>. The default Y'CbCr quantization is limited range. The chromaticities of the primary colors and the white reference are:</para> <table frame="none"> @@ -817,9 +899,11 @@ The xvYCC encodings always use full range quantization.</para> <section id="col-srgb"> <title>Colorspace sRGB (<constant>V4L2_COLORSPACE_SRGB</constant>)</title> - <para>The <xref linkend="srgb" /> standard defines the colorspace used by most webcams and computer graphics. The -default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_SYCC</constant>. The default Y'CbCr quantization -is full range. The chromaticities of the primary colors and the white reference are:</para> + <para>The <xref linkend="srgb" /> standard defines the colorspace used by most webcams +and computer graphics. The default transfer function is <constant>V4L2_XFER_FUNC_SRGB</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_SYCC</constant>. The default Y'CbCr +quantization is full range. The chromaticities of the primary colors and the white +reference are:</para> <table frame="none"> <title>sRGB Chromaticities</title> <tgroup cols="3" align="left"> @@ -896,6 +980,7 @@ values before quantization, but this encoding does not do that.</para> <title>Colorspace Adobe RGB (<constant>V4L2_COLORSPACE_ADOBERGB</constant>)</title> <para>The <xref linkend="adobergb" /> standard defines the colorspace used by computer graphics that use the AdobeRGB colorspace. This is also known as the <xref linkend="oprgb" /> standard. +The default transfer function is <constant>V4L2_XFER_FUNC_ADOBERGB</constant>. The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_601</constant>. The default Y'CbCr quantization is limited range. The chromaticities of the primary colors and the white reference are:</para> @@ -967,7 +1052,8 @@ SMPTE 170M/BT.601. The Y'CbCr quantization is limited range.</para> <section id="col-bt2020"> <title>Colorspace BT.2020 (<constant>V4L2_COLORSPACE_BT2020</constant>)</title> <para>The <xref linkend="itu2020" /> standard defines the colorspace used by Ultra-high definition -television (UHDTV). The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_BT2020</constant>. +television (UHDTV). The default transfer function is <constant>V4L2_XFER_FUNC_709</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_BT2020</constant>. The default R'G'B' quantization is limited range (!), and so is the default Y'CbCr quantization. The chromaticities of the primary colors and the white reference are:</para> <table frame="none"> @@ -1080,10 +1166,74 @@ clamped to the range [-0.5…0.5]. The Y'CbCr quantization is limited range clamped to the range [-0.5…0.5]. The Yc'CbcCrc quantization is limited range.</para> </section> + <section id="col-dcip3"> + <title>Colorspace DCI-P3 (<constant>V4L2_COLORSPACE_DCI_P3</constant>)</title> + <para>The <xref linkend="smpte431" /> standard defines the colorspace used by cinema +projectors that use the DCI-P3 colorspace. +The default transfer function is <constant>V4L2_XFER_FUNC_DCI_P3</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_709</constant>. Note that this +colorspace does not specify a Y'CbCr encoding since it is not meant to be encoded +to Y'CbCr. So this default Y'CbCr encoding was picked because it is the HDTV +encoding. The default Y'CbCr quantization is limited range. The chromaticities of +the primary colors and the white reference are:</para> + <table frame="none"> + <title>DCI-P3 Chromaticities</title> + <tgroup cols="3" align="left"> + &cs-str; + <thead> + <row> + <entry>Color</entry> + <entry>x</entry> + <entry>y</entry> + </row> + </thead> + <tbody valign="top"> + <row> + <entry>Red</entry> + <entry>0.6800</entry> + <entry>0.3200</entry> + </row> + <row> + <entry>Green</entry> + <entry>0.2650</entry> + <entry>0.6900</entry> + </row> + <row> + <entry>Blue</entry> + <entry>0.1500</entry> + <entry>0.0600</entry> + </row> + <row> + <entry>White Reference</entry> + <entry>0.3140</entry> + <entry>0.3510</entry> + </row> + </tbody> + </tgroup> + </table> + <variablelist> + <varlistentry> + <term>Transfer function:</term> + <listitem> + <para>L' = L<superscript>1/2.6</superscript></para> + </listitem> + </varlistentry> + <varlistentry> + <term>Inverse Transfer function:</term> + <listitem> + <para>L = L'<superscript>2.6</superscript></para> + </listitem> + </varlistentry> + </variablelist> + <para>Y'CbCr encoding is not specified. V4L2 defaults to Rec. 709.</para> + </section> + <section id="col-smpte-240m"> <title>Colorspace SMPTE 240M (<constant>V4L2_COLORSPACE_SMPTE240M</constant>)</title> - <para>The <xref linkend="smpte240m" /> standard was an interim standard used during the early days of HDTV (1988-1998). -It has been superseded by Rec. 709. The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_SMPTE240M</constant>. + <para>The <xref linkend="smpte240m" /> standard was an interim standard used during +the early days of HDTV (1988-1998). It has been superseded by Rec. 709. +The default transfer function is <constant>V4L2_XFER_FUNC_SMPTE240M</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_SMPTE240M</constant>. The default Y'CbCr quantization is limited range. The chromaticities of the primary colors and the white reference are:</para> <table frame="none"> @@ -1156,8 +1306,10 @@ clamped to the range [-0.5…0.5]. The Y'CbCr quantization is limited range <section id="col-sysm"> <title>Colorspace NTSC 1953 (<constant>V4L2_COLORSPACE_470_SYSTEM_M</constant>)</title> <para>This standard defines the colorspace used by NTSC in 1953. In practice this -colorspace is obsolete and SMPTE 170M should be used instead. The default Y'CbCr encoding -is <constant>V4L2_YCBCR_ENC_601</constant>. The default Y'CbCr quantization is limited range. +colorspace is obsolete and SMPTE 170M should be used instead. +The default transfer function is <constant>V4L2_XFER_FUNC_709</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_601</constant>. +The default Y'CbCr quantization is limited range. The chromaticities of the primary colors and the white reference are:</para> <table frame="none"> <title>NTSC 1953 Chromaticities</title> @@ -1234,8 +1386,10 @@ This transform is identical to one defined in SMPTE 170M/BT.601.</para> <section id="col-sysbg"> <title>Colorspace EBU Tech. 3213 (<constant>V4L2_COLORSPACE_470_SYSTEM_BG</constant>)</title> <para>The <xref linkend="tech3213" /> standard defines the colorspace used by PAL/SECAM in 1975. In practice this -colorspace is obsolete and SMPTE 170M should be used instead. The default Y'CbCr encoding -is <constant>V4L2_YCBCR_ENC_601</constant>. The default Y'CbCr quantization is limited range. +colorspace is obsolete and SMPTE 170M should be used instead. +The default transfer function is <constant>V4L2_XFER_FUNC_709</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_601</constant>. +The default Y'CbCr quantization is limited range. The chromaticities of the primary colors and the white reference are:</para> <table frame="none"> <title>EBU Tech. 3213 Chromaticities</title> @@ -1308,7 +1462,8 @@ This transform is identical to one defined in SMPTE 170M/BT.601.</para> <section id="col-jpeg"> <title>Colorspace JPEG (<constant>V4L2_COLORSPACE_JPEG</constant>)</title> <para>This colorspace defines the colorspace used by most (Motion-)JPEG formats. The chromaticities -of the primary colors and the white reference are identical to sRGB. The Y'CbCr encoding is +of the primary colors and the white reference are identical to sRGB. The transfer +function use is <constant>V4L2_XFER_FUNC_SRGB</constant>. The Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_601</constant> with full range quantization where Y' is scaled to [0…255] and Cb/Cr are scaled to [-128…128] and then clipped to [-128…127].</para> @@ -1321,6 +1476,41 @@ and <constant>V4L2_QUANTIZATION_FULL_RANGE</constant>.</para> </section> + <section> + <title>Detailed Transfer Function Descriptions</title> + <section id="xf-smpte-2084"> + <title>Transfer Function SMPTE 2084 (<constant>V4L2_XFER_FUNC_SMPTE2084</constant>)</title> + <para>The <xref linkend="smpte2084" /> standard defines the transfer function used by +High Dynamic Range content.</para> + <variablelist> + <varlistentry> + <term>Constants:</term> + <listitem> + <para>m1 = (2610 / 4096) / 4</para> + <para>m2 = (2523 / 4096) * 128</para> + <para>c1 = 3424 / 4096</para> + <para>c2 = (2413 / 4096) * 32</para> + <para>c3 = (2392 / 4096) * 32</para> + </listitem> + </varlistentry> + <varlistentry> + <term>Transfer function:</term> + <listitem> + <para>L' = ((c1 + c2 * L<superscript>m1</superscript>) / (1 + c3 * L<superscript>m1</superscript>))<superscript>m2</superscript></para> + </listitem> + </varlistentry> + </variablelist> + <variablelist> + <varlistentry> + <term>Inverse Transfer function:</term> + <listitem> + <para>L = (max(L'<superscript>1/m2</superscript> - c1, 0) / (c2 - c3 * L'<superscript>1/m2</superscript>))<superscript>1/m1</superscript></para> + </listitem> + </varlistentry> + </variablelist> + </section> + </section> + <section id="pixfmt-indexed"> <title>Indexed Format</title> @@ -1429,6 +1619,7 @@ information.</para> &sub-y12; &sub-y10b; &sub-y16; + &sub-y16-be; &sub-uv8; &sub-yuyv; &sub-uyvy; @@ -1541,7 +1732,7 @@ extended control <constant>V4L2_CID_MPEG_STREAM_TYPE</constant>, see <section id="sdr-formats"> <title>SDR Formats</title> - <para>These formats are used for <link linkend="sdr">SDR Capture</link> + <para>These formats are used for <link linkend="sdr">SDR</link> interface only.</para> &sub-sdr-cu08; |