media/v4l/dev-decoder.rst

65    height for given coded resolution.
67 coded resolution
68    stream resolution in pixels aligned to codec and hardware requirements;
69    typically visible resolution rounded up to full macroblocks;
70    see also: visible resolution.
73    width for given coded resolution.
132    height in pixels for given source resolution; relevant to encoders only.
134 source resolution
135    resolution in pixels of source frames being source to the encoder and
136    subject to further cropping to the bounds of visible resolution; relevant to
140    width in pixels for given source resolution; relevant to encoders only.
147    for example: coded resolution, visible resolution, codec profile.
150    height for given visible resolution; display height.
152 visible resolution
153    stream resolution of the visible picture, in pixels, to be used for
154    display purposes; must be smaller or equal to coded resolution;
155    display resolution.
158    width for given visible resolution; display width.
218      parser and if the decoder supports dynamic resolution changes.
261          coded resolution of the stream; required only if it cannot be parsed
263          use this resolution as a placeholder resolution that will likely change
264          as soon as it can parse the actual coded resolution from the stream.
279      resolution instantly based on the width and height returned by
281      However, for coded formats that include stream resolution information,
348 4.  **This step only applies to coded formats that contain resolution information
364     * If the client has not set the coded resolution of the stream on its own,
386        those parsed by the decoder, a `Dynamic Resolution Change` will be
409           frame buffer resolution for the decoded frames.
428 2.  **Optional.** Acquire the visible resolution via
442           the visible rectangle; it must fit within the frame buffer resolution
448           corresponds to the coded resolution of the stream.
453           will be equal to the visible resolution of the stream.
456           the rectangle within the coded resolution to be output to
500        hardware limitations). After parsing a resolution of 1920x1088 or lower,
502        but after parsing resolution higher than 1920x1088, the decoder will not
503        return RGB, unsupported for this resolution.
505        However, subsequent resolution change event triggered after
506        discovering a resolution change within the same stream may switch
507        the stream into a lower resolution and :c:func:`VIDIOC_ENUM_FMT`
523          frame buffer resolution of the decoded stream; typically unchanged from
528      to their default values, based on the new resolution, as described in the
551          the visible rectangle; it must fit within the frame buffer resolution
647     resolution changes can be accommodated.
661           a format representing the maximum framebuffer resolution to be
681        * set width and height of the ``OUTPUT`` format to desired coded resolution to
763   ``V4L2_EVENT_SRC_CH_RESOLUTION`` is pending, the `Dynamic Resolution
852    A seek may result in the `Dynamic Resolution Change` sequence being
889 Dynamic Resolution Change
892 Streams that include resolution metadata in the bytestream may require switching
893 to a different resolution during the decoding.
897    Not all decoders can detect resolution changes. Those that do set the
905 * coded resolution (``OUTPUT`` width and height),
907 * visible resolution (selection rectangles),
915 1.  After encountering a resolution change in the stream, the decoder sends a
922        values applying to the stream after the resolution change, including
926     the resolution change point.
961    During the resolution change sequence, the ``OUTPUT`` queue must remain
966    queue and this remains true for the duration of the entire resolution change
1008      such as the `Dynamic Resolution Change` sequence, before continuing with