am b605944f: Camera3: Document cropping behavior
* commit 'b605944f0a0590d0f31d48a14eaf8e6a075ddba1': Camera3: Document cropping behavior
This commit is contained in:
Eino-Ville Talvala
Android Git Automerger
commit
c2f433d00c
1 changed files with 158 additions and 2 deletions
|
|
@ -42,7 +42,8 @@
|
|||
* S2. Startup and operation sequencing
|
||||
* S3. Operational modes
|
||||
* S4. 3A modes and state machines
|
||||
* S5. Error management
|
||||
* S5. Cropping
|
||||
* S6. Error management
|
||||
*/
|
||||
|
||||
/**
|
||||
|
|
@ -744,7 +745,162 @@
|
|||
*/
|
||||
|
||||
/**
|
||||
* S5. Error management:
|
||||
* S5. Cropping:
|
||||
*
|
||||
* Cropping of the full pixel array (for digital zoom and other use cases where
|
||||
* a smaller FOV is desirable) is communicated through the
|
||||
* ANDROID_SCALER_CROP_REGION setting. This is a per-request setting, and can
|
||||
* change on a per-request basis, which is critical for implementing smooth
|
||||
* digital zoom.
|
||||
*
|
||||
* The region is defined as a rectangle (x, y, width, height), with (x, y)
|
||||
* describing the top-left corner of the rectangle. The rectangle is defined on
|
||||
* the coordinate system of the sensor active pixel array, with (0,0) being the
|
||||
* top-left pixel of the active pixel array. Therefore, the width and height
|
||||
* cannot be larger than the dimensions reported in the
|
||||
* ANDROID_SENSOR_ACTIVE_PIXEL_ARRAY static info field. The minimum allowed
|
||||
* width and height are reported by the HAL through the
|
||||
* ANDROID_SCALER_MAX_DIGITAL_ZOOM static info field, which describes the
|
||||
* maximum supported zoom factor. Therefore, the minimum crop region width and
|
||||
* height are:
|
||||
*
|
||||
* {width, height} =
|
||||
* { floor(ANDROID_SENSOR_ACTIVE_PIXEL_ARRAY[0] /
|
||||
* ANDROID_SCALER_MAX_DIGITAL_ZOOM),
|
||||
* floor(ANDROID_SENSOR_ACTIVE_PIXEL_ARRAY[1] /
|
||||
* ANDROID_SCALER_MAX_DIGITAL_ZOOM) }
|
||||
*
|
||||
* If the crop region needs to fulfill specific requirements (for example, it
|
||||
* needs to start on even coordinates, and its width/height needs to be even),
|
||||
* the HAL must do the necessary rounding and write out the final crop region
|
||||
* used in the output result metadata. Similarly, if the HAL implements video
|
||||
* stabilization, it must adjust the result crop region to describe the region
|
||||
* actually included in the output after video stabilization is applied. In
|
||||
* general, a camera-using application must be able to determine the field of
|
||||
* view it is receiving based on the crop region, the dimensions of the image
|
||||
* sensor, and the lens focal length.
|
||||
*
|
||||
* Since the crop region applies to all streams, which may have different aspect
|
||||
* ratios than the crop region, the exact sensor region used for each stream may
|
||||
* be smaller than the crop region. Specifically, each stream should maintain
|
||||
* square pixels and its aspect ratio by minimally further cropping the defined
|
||||
* crop region. If the stream's aspect ratio is wider than the crop region, the
|
||||
* stream should be further cropped vertically, and if the stream's aspect ratio
|
||||
* is narrower than the crop region, the stream should be further cropped
|
||||
* horizontally.
|
||||
*
|
||||
* In all cases, the stream crop must be centered within the full crop region,
|
||||
* and each stream is only either cropped horizontally or vertical relative to
|
||||
* the full crop region, never both.
|
||||
*
|
||||
* For example, if two streams are defined, a 640x480 stream (4:3 aspect), and a
|
||||
* 1280x720 stream (16:9 aspect), below demonstrates the expected output regions
|
||||
* for each stream for a few sample crop regions, on a hypothetical 3 MP (2000 x
|
||||
* 1500 pixel array) sensor.
|
||||
*
|
||||
* Crop region: (500, 375, 1000, 750) (4:3 aspect ratio)
|
||||
*
|
||||
* 640x480 stream crop: (500, 375, 1000, 750) (equal to crop region)
|
||||
* 1280x720 stream crop: (500, 469, 1000, 562) (marked with =)
|
||||
*
|
||||
* 0 1000 2000
|
||||
* +---------+---------+---------+----------+
|
||||
* | Active pixel array |
|
||||
* | |
|
||||
* | |
|
||||
* + +-------------------+ + 375
|
||||
* | | | |
|
||||
* | O===================O |
|
||||
* | I 1280x720 stream I |
|
||||
* + I I + 750
|
||||
* | I I |
|
||||
* | O===================O |
|
||||
* | | | |
|
||||
* + +-------------------+ + 1125
|
||||
* | Crop region, 640x480 stream |
|
||||
* | |
|
||||
* | |
|
||||
* +---------+---------+---------+----------+ 1500
|
||||
*
|
||||
* Crop region: (500, 375, 1333, 750) (16:9 aspect ratio)
|
||||
*
|
||||
* 640x480 stream crop: (666, 375, 1000, 750) (marked with =)
|
||||
* 1280x720 stream crop: (500, 375, 1333, 750) (equal to crop region)
|
||||
*
|
||||
* 0 1000 2000
|
||||
* +---------+---------+---------+----------+
|
||||
* | Active pixel array |
|
||||
* | |
|
||||
* | |
|
||||
* + +---O==================O---+ + 375
|
||||
* | | I 640x480 stream I | |
|
||||
* | | I I | |
|
||||
* | | I I | |
|
||||
* + | I I | + 750
|
||||
* | | I I | |
|
||||
* | | I I | |
|
||||
* | | I I | |
|
||||
* + +---O==================O---+ + 1125
|
||||
* | Crop region, 1280x720 stream |
|
||||
* | |
|
||||
* | |
|
||||
* +---------+---------+---------+----------+ 1500
|
||||
*
|
||||
* Crop region: (500, 375, 750, 750) (1:1 aspect ratio)
|
||||
*
|
||||
* 640x480 stream crop: (500, 469, 750, 562) (marked with =)
|
||||
* 1280x720 stream crop: (500, 543, 750, 414) (marged with #)
|
||||
*
|
||||
* 0 1000 2000
|
||||
* +---------+---------+---------+----------+
|
||||
* | Active pixel array |
|
||||
* | |
|
||||
* | |
|
||||
* + +--------------+ + 375
|
||||
* | O==============O |
|
||||
* | ################ |
|
||||
* | # # |
|
||||
* + # # + 750
|
||||
* | # # |
|
||||
* | ################ 1280x720 |
|
||||
* | O==============O 640x480 |
|
||||
* + +--------------+ + 1125
|
||||
* | Crop region |
|
||||
* | |
|
||||
* | |
|
||||
* +---------+---------+---------+----------+ 1500
|
||||
*
|
||||
* And a final example, a 1024x1024 square aspect ratio stream instead of the
|
||||
* 480p stream:
|
||||
*
|
||||
* Crop region: (500, 375, 1000, 750) (4:3 aspect ratio)
|
||||
*
|
||||
* 1024x1024 stream crop: (625, 375, 750, 750) (marked with #)
|
||||
* 1280x720 stream crop: (500, 469, 1000, 562) (marked with =)
|
||||
*
|
||||
* 0 1000 2000
|
||||
* +---------+---------+---------+----------+
|
||||
* | Active pixel array |
|
||||
* | |
|
||||
* | 1024x1024 stream |
|
||||
* + +--###############--+ + 375
|
||||
* | | # # | |
|
||||
* | O===================O |
|
||||
* | I 1280x720 stream I |
|
||||
* + I I + 750
|
||||
* | I I |
|
||||
* | O===================O |
|
||||
* | | # # | |
|
||||
* + +--###############--+ + 1125
|
||||
* | Crop region |
|
||||
* | |
|
||||
* | |
|
||||
* +---------+---------+---------+----------+ 1500
|
||||
*
|
||||
*/
|
||||
|
||||
/**
|
||||
* S6. Error management:
|
||||
*
|
||||
* Camera HAL device ops functions that have a return value will all return
|
||||
* -ENODEV / NULL in case of a serious error. This means the device cannot
|
||||
|
|
|
|||
Loading…
Reference in a new issue