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Diffstat (limited to 'Documentation/media/uapi/v4l/selection-api-005.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/selection-api-005.rst | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/Documentation/media/uapi/v4l/selection-api-005.rst b/Documentation/media/uapi/v4l/selection-api-005.rst index 94731a13efdb..5b47a28ac6d7 100644 --- a/Documentation/media/uapi/v4l/selection-api-005.rst +++ b/Documentation/media/uapi/v4l/selection-api-005.rst @@ -16,19 +16,19 @@ cropping from an image inside a memory buffer. The application could configure a capture device to fill only a part of an image by abusing V4L2 API. Cropping a smaller image from a larger one is achieved by setting the field ``bytesperline`` at struct -:ref:`v4l2_pix_format <v4l2-pix-format>`. +:c:type:`v4l2_pix_format`. Introducing an image offsets could be done by modifying field ``m_userptr`` at struct -:ref:`v4l2_buffer <v4l2-buffer>` before calling +:c:type:`v4l2_buffer` before calling :ref:`VIDIOC_QBUF`. Those operations should be avoided because they are not portable (endianness), and do not work for macroblock and Bayer formats and mmap buffers. The selection API deals with configuration of buffer cropping/composing in a clear, intuitive and portable way. Next, with the selection API the concepts of the padded target and constraints -flags are introduced. Finally, struct :ref:`v4l2_crop <v4l2-crop>` -and struct :ref:`v4l2_cropcap <v4l2-cropcap>` have no reserved +flags are introduced. Finally, struct :c:type:`v4l2_crop` +and struct :c:type:`v4l2_cropcap` have no reserved fields. Therefore there is no way to extend their functionality. The new -struct :ref:`v4l2_selection <v4l2-selection>` provides a lot of place +struct :c:type:`v4l2_selection` provides a lot of place for future extensions. Driver developers are encouraged to implement only selection API. The former cropping API would be simulated using the new one. |