Lines Matching full:buffer
16 A buffer contains data exchanged by application and driver using one of
18 planes, while the buffer structure acts as a container for the planes.
33 ``V4L2_BUF_FLAG_TSTAMP_SRC_MASK`` in :ref:`buffer-flags`. These flags
40 flags are copied from the OUTPUT video buffer to the CAPTURE video
41 buffer.
47 V4L2 exposes parameters that influence the buffer size, or the way data is
48 laid out in the buffer. Those parameters are exposed through both formats and
50 that modifies the direction in which pixels are stored in the buffer, as well
51 as the buffer size when the selected format includes padding at the end of
54 The set of information needed to interpret the content of a buffer (e.g. the
56 collectively referred to in the rest of this section as the buffer layout.
58 Controls that can modify the buffer layout shall set the
61 Modifying formats or controls that influence the buffer size or layout require
76 selection rectangles. When those ioctls result in a buffer size or layout
80 Controls that only influence the buffer layout can be modified at any time
81 when the stream is stopped. As they don't influence the buffer size, no
82 special handling is needed to synchronize those controls with buffer
86 Formats and controls that influence the buffer size interact with buffer
106 value into account to compute the buffer size to allocate. Applications can
118 influences the buffer size while buffers are allocated shall cause the format
120 buffer too small for the current format or controls shall cause the
123 Buffer reallocation is an expensive operation. To avoid that cost, drivers can
124 (and are encouraged to) allow format or controls that influence the buffer
139 allowed to return a ``EBUSY`` error from these ioctls if any buffer is
143 :c:func:`VIDIOC_QBUF` ioctl if the buffer being queued is too small for the
147 Userspace applications can query the buffer size required for a given format
150 buffer size.
180 - Number of the buffer, set by the application except when calling
190 - Type of the buffer, same as struct
197 - The number of bytes occupied by the data in the buffer. It depends
198 on the negotiated data format and may change with each buffer for
203 size of the buffer (see the ``length`` field of this struct) by
209 - Flags set by the application or driver, see :ref:`buffer-flags`.
213 - Indicates the field order of the image in the buffer, see
214 :c:type:`v4l2_field`. This field is not used when the buffer
223 :ref:`buffer-flags`. For output streams the driver stores the
251 free buffer space. A repeated frame was displayed again by an
274 ``V4L2_MEMORY_MMAP`` this is the offset of the buffer from the
283 ``V4L2_MEMORY_USERPTR`` this is a pointer to the buffer (casted to
298 a DMABUF buffer.
302 - Size of the buffer (not the payload) in bytes for the
317 - The file descriptor of the request to queue the buffer to. If the flag
318 ``V4L2_BUF_FLAG_REQUEST_FD`` is set, then the buffer will be
394 this is a file descriptor associated with a DMABUF buffer, similar
432 - Buffer of a single-planar video capture stream, see
436 - Buffer of a multi-planar video capture stream, see
440 - Buffer of a single-planar video output stream, see
444 - Buffer of a multi-planar video output stream, see :ref:`output`.
447 - Buffer for video overlay, see :ref:`overlay`.
450 - Buffer of a raw VBI capture stream, see :ref:`raw-vbi`.
453 - Buffer of a raw VBI output stream, see :ref:`raw-vbi`.
456 - Buffer of a sliced VBI capture stream, see :ref:`sliced`.
459 - Buffer of a sliced VBI output stream, see :ref:`sliced`.
462 - Buffer for video output overlay (OSD), see :ref:`osd`.
465 - Buffer for Software Defined Radio (SDR) capture stream, see
469 - Buffer for Software Defined Radio (SDR) output stream, see
473 - Buffer for metadata capture, see :ref:`metadata`.
476 - Buffer for metadata output, see :ref:`metadata`.
482 Buffer Flags
502 - The buffer resides in device memory and has been mapped into the
513 - Internally drivers maintain two buffer queues, an incoming and
514 outgoing queue. When this flag is set, the buffer is currently on
516 after the buffer has been filled (capture devices) or displayed
525 - When this flag is set, the buffer is currently on the outgoing
529 cleared. Of course a buffer cannot be on both queues at the same
532 buffer is in "dequeued" state, in the application domain so to
538 - When this flag is set, the buffer has been dequeued successfully,
540 streaming may continue as normal and the buffer may be reused
547 - This buffer is part of a request that hasn't been queued yet.
553 ioctl. It may be set by video capture devices when the buffer
587 - The buffer has been prepared for I/O and can be queued by the
597 - Caches do not have to be invalidated for this buffer. Typically
599 buffer is not going to be touched by the CPU, instead the buffer
606 - Caches do not have to be cleaned for this buffer. Typically
608 this buffer has not been created by the CPU but by some
614 - Last buffer produced by the hardware. mem2mem codec drivers set
615 this flag on the capture queue for the last buffer when the
618 hardware limitations, the last buffer may be empty. In this case
634 and operation with buffer flags and timestamp mask.
650 - The buffer timestamp has been taken from the ``CLOCK_MONOTONIC``
657 - The CAPTURE buffer timestamp has been taken from the corresponding
658 OUTPUT buffer. This flag applies only to mem2mem devices.
674 - End Of Frame. The buffer timestamp has been taken when the last
684 - Start Of Exposure. The buffer timestamp has been taken when the
686 ``V4L2_BUF_TYPE_VIDEO_CAPTURE`` buffer type.
707 - The buffer is used for :ref:`memory mapping <mmap>` I/O.
710 - The buffer is used for :ref:`user pointer <userp>` I/O.
716 - The buffer is used for :ref:`DMA shared buffer <dmabuf>` I/O.