Lines Matching refs:alpha
17 presence of an alpha component or additional padding bits.
19 The usage and value of the alpha bits in formats that support them (named ARGB
20 or a permutation thereof, collectively referred to as alpha formats) depend on
22 (including capture queues of mem-to-mem devices) fill the alpha component in
23 memory. When the device captures an alpha channel the alpha component will have
24 a meaningful value. Otherwise, when the device doesn't capture an alpha channel
25 but can set the alpha bit to a user-configurable value, the
26 :ref:`V4L2_CID_ALPHA_COMPONENT <v4l2-alpha-component>` control is used to
27 specify that alpha value, and the alpha component of all pixels will be set to
29 an alpha component (XRGB or XBGR) must be used instead of an alpha format.
32 and :ref:`video output overlay <osd>` devices) read the alpha component from
33 memory. When the device processes the alpha channel the alpha component must be
35 without an alpha component (XRGB or XBGR) must be used instead of an alpha
46 respectively. 'a' denotes bits of the alpha component (if supported by the
771 their alpha bits ``(a)`` is ill-defined and they are interpreted as in either