diff --git a/Documentation/DocBook/media/v4l/selection-api.xml b/Documentation/DocBook/media/v4l/selection-api.xml index 2f0bdb4d5551..b299e4779354 100644 --- a/Documentation/DocBook/media/v4l/selection-api.xml +++ b/Documentation/DocBook/media/v4l/selection-api.xml @@ -52,6 +52,10 @@ cropping and composing rectangles have the same size. + +For complete list of the available selection targets see table +
@@ -186,7 +190,7 @@ V4L2_SEL_TGT_COMPOSE_ACTIVE target.
- Scaling control. + Scaling control An application can detect if scaling is performed by comparing the width and the height of rectangles obtained using V4L2_SEL_TGT_CROP_ACTIVE @@ -200,7 +204,7 @@ the scaling ratios using these values.
- Comparison with old cropping API. + Comparison with old cropping API The selection API was introduced to cope with deficiencies of previous API , that was designed to control simple capture diff --git a/Documentation/DocBook/media/v4l/vidioc-g-selection.xml b/Documentation/DocBook/media/v4l/vidioc-g-selection.xml index a9d36e0c090e..bb04eff75f45 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-selection.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-selection.xml @@ -58,43 +58,43 @@ The ioctls are used to query and configure selection rectangles. - To query the cropping (composing) rectangle set -&v4l2-selection;::type to the respective buffer type. Do not -use multiplanar buffers. Use V4L2_BUF_TYPE_VIDEO_CAPTURE + To query the cropping (composing) rectangle set &v4l2-selection; + type field to the respective buffer type. +Do not use multiplanar buffers. Use V4L2_BUF_TYPE_VIDEO_CAPTURE instead of V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE . Use V4L2_BUF_TYPE_VIDEO_OUTPUT instead of V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE . The next step is -setting &v4l2-selection;::target to value - V4L2_SEL_TGT_CROP_ACTIVE ( +setting the value of &v4l2-selection; target field +to V4L2_SEL_TGT_CROP_ACTIVE ( V4L2_SEL_TGT_COMPOSE_ACTIVE ). Please refer to table or for additional -targets. Fields &v4l2-selection;::flags and - &v4l2-selection;::reserved are ignored and they -must be filled with zeros. The driver fills the rest of the structure or +targets. The flags and reserved + fields of &v4l2-selection; are ignored and they must be filled +with zeros. The driver fills the rest of the structure or returns &EINVAL; if incorrect buffer type or target was used. If cropping (composing) is not supported then the active rectangle is not mutable and it is -always equal to the bounds rectangle. Finally, structure -&v4l2-selection;::r is filled with the current cropping +always equal to the bounds rectangle. Finally, the &v4l2-rect; +r rectangle is filled with the current cropping (composing) coordinates. The coordinates are expressed in driver-dependent units. The only exception are rectangles for images in raw formats, whose coordinates are always expressed in pixels. - To change the cropping (composing) rectangle set -&v4l2-selection;::type to the respective buffer type. Do not + To change the cropping (composing) rectangle set the &v4l2-selection; +type field to the respective buffer type. Do not use multiplanar buffers. Use V4L2_BUF_TYPE_VIDEO_CAPTURE instead of V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE . Use V4L2_BUF_TYPE_VIDEO_OUTPUT instead of V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE . The next step is -setting &v4l2-selection;::target to value - V4L2_SEL_TGT_CROP_ACTIVE ( +setting the value of &v4l2-selection; target to +V4L2_SEL_TGT_CROP_ACTIVE ( V4L2_SEL_TGT_COMPOSE_ACTIVE ). Please refer to table or for additional -targets. Set desired active area into the field -&v4l2-selection;::r . Field -&v4l2-selection;::reserved is ignored and must be filled with -zeros. The driver may adjust the rectangle coordinates. An application may -introduce constraints to control rounding behaviour. Set the field - &v4l2-selection;::flags to one of values: +targets. The &v4l2-rect; r rectangle need to be +set to the desired active area. Field &v4l2-selection; reserved + is ignored and must be filled with zeros. The driver may adjust +coordinates of the requested rectangle. An application may +introduce constraints to control rounding behaviour. The &v4l2-selection; +flags field must be set to one of the following: @@ -129,7 +129,7 @@ and vertical offset and sizes are chosen according to following priority: - Satisfy constraints from &v4l2-selection;::flags. + Satisfy constraints from &v4l2-selection; flags. Adjust width, height, left, and top to hardware limits and alignments. @@ -145,7 +145,7 @@ and vertical offset and sizes are chosen according to following priority: -On success the field &v4l2-selection;::r contains +On success the &v4l2-rect; r field contains the adjusted rectangle. When the parameters are unsuitable the application may modify the cropping (composing) or image parameters and repeat the cycle until satisfactory parameters have been negotiated. If constraints flags have to be @@ -162,38 +162,38 @@ exist no rectangle that satisfies the constraints. V4L2_SEL_TGT_CROP_ACTIVE - 0 - area that is currently cropped by hardware + 0x0000 + The area that is currently cropped by hardware. V4L2_SEL_TGT_CROP_DEFAULT - 1 - suggested cropping rectangle that covers the "whole picture" + 0x0001 + Suggested cropping rectangle that covers the "whole picture". V4L2_SEL_TGT_CROP_BOUNDS - 2 - limits for the cropping rectangle + 0x0002 + Limits for the cropping rectangle. V4L2_SEL_TGT_COMPOSE_ACTIVE - 256 - area to which data are composed by hardware + 0x0100 + The area to which data is composed by hardware. V4L2_SEL_TGT_COMPOSE_DEFAULT - 257 - suggested composing rectangle that covers the "whole picture" + 0x0101 + Suggested composing rectangle that covers the "whole picture". V4L2_SEL_TGT_COMPOSE_BOUNDS - 258 - limits for the composing rectangle + 0x0102 + Limits for the composing rectangle. V4L2_SEL_TGT_COMPOSE_PADDED - 259 - the active area and all padding pixels that are inserted or modified by the hardware + 0x0103 + The active area and all padding pixels that are inserted or modified by hardware. @@ -209,12 +209,14 @@ exist no rectangle that satisfies the constraints. V4L2_SEL_FLAG_GE 0x00000001 - indicate that adjusted rectangle must contain a rectangle from &v4l2-selection;::r + Indicates that the adjusted rectangle must contain the original + &v4l2-selection; r rectangle. V4L2_SEL_FLAG_LE 0x00000002 - indicate that adjusted rectangle must be inside a rectangle from &v4l2-selection;::r + Indicates that the adjusted rectangle must be inside the original + &v4l2-rect; r rectangle. @@ -245,27 +247,29 @@ exist no rectangle that satisfies the constraints. __u32 type - Type of the buffer (from &v4l2-buf-type;) + Type of the buffer (from &v4l2-buf-type;). __u32 target - used to select between cropping and composing rectangles + Used to select between cropping + and composing rectangles. __u32 flags - control over coordinates adjustments, refer to selection flags + Flags controlling the selection rectangle adjustments, refer to + selection flags. &v4l2-rect; r - selection rectangle + The selection rectangle. __u32 reserved[9] - Reserved fields for future use + Reserved fields for future use. @@ -278,24 +282,24 @@ exist no rectangle that satisfies the constraints. EINVAL - The buffer &v4l2-selection;::type -or &v4l2-selection;::target is not supported, or -the &v4l2-selection;::flags are invalid. + Given buffer type type or +the selection target target is not supported, +or the flags argument is not valid. ERANGE - it is not possible to adjust a rectangle -&v4l2-selection;::r that satisfies all contraints from - &v4l2-selection;::flags . + It is not possible to adjust &v4l2-rect; +r rectangle to satisfy all contraints given in the +flags argument. EBUSY - it is not possible to apply change of selection rectangle at the moment. -Usually because streaming is in progress. + It is not possible to apply change of the selection rectangle +at the moment. Usually because streaming is in progress. diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index 3fab6cacccbe..c9c9a4680cc5 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -762,20 +762,20 @@ struct v4l2_crop { /* Selection targets */ -/* current cropping area */ -#define V4L2_SEL_TGT_CROP_ACTIVE 0 -/* default cropping area */ -#define V4L2_SEL_TGT_CROP_DEFAULT 1 -/* cropping bounds */ -#define V4L2_SEL_TGT_CROP_BOUNDS 2 -/* current composing area */ -#define V4L2_SEL_TGT_COMPOSE_ACTIVE 256 -/* default composing area */ -#define V4L2_SEL_TGT_COMPOSE_DEFAULT 257 -/* composing bounds */ -#define V4L2_SEL_TGT_COMPOSE_BOUNDS 258 -/* current composing area plus all padding pixels */ -#define V4L2_SEL_TGT_COMPOSE_PADDED 259 +/* Current cropping area */ +#define V4L2_SEL_TGT_CROP_ACTIVE 0x0000 +/* Default cropping area */ +#define V4L2_SEL_TGT_CROP_DEFAULT 0x0001 +/* Cropping bounds */ +#define V4L2_SEL_TGT_CROP_BOUNDS 0x0002 +/* Current composing area */ +#define V4L2_SEL_TGT_COMPOSE_ACTIVE 0x0100 +/* Default composing area */ +#define V4L2_SEL_TGT_COMPOSE_DEFAULT 0x0101 +/* Composing bounds */ +#define V4L2_SEL_TGT_COMPOSE_BOUNDS 0x0102 +/* Current composing area plus all padding pixels */ +#define V4L2_SEL_TGT_COMPOSE_PADDED 0x0103 /** * struct v4l2_selection - selection info @@ -785,7 +785,7 @@ struct v4l2_crop { * @r: coordinates of selection window * @reserved: for future use, rounds structure size to 64 bytes, set to zero * - * Hardware may use multiple helper window to process a video stream. + * Hardware may use multiple helper windows to process a video stream. * The structure is used to exchange this selection areas between * an application and a driver. */