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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/dvb/dmx-fread.rst | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/userspace-api/media/dvb/dmx-fread.rst | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/dvb/dmx-fread.rst b/Documentation/userspace-api/media/dvb/dmx-fread.rst new file mode 100644 index 000000000..78e9daef5 --- /dev/null +++ b/Documentation/userspace-api/media/dvb/dmx-fread.rst @@ -0,0 +1,77 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: DTV.dmx + +.. _dmx_fread: + +======================= +Digital TV demux read() +======================= + +Name +---- + +Digital TV demux read() + +Synopsis +-------- + +.. c:function:: size_t read(int fd, void *buf, size_t count) + +Arguments +--------- + +``fd`` + File descriptor returned by a previous call to :c:func:`open()`. + + ``buf`` + Buffer to be filled + +``count`` + Max number of bytes to read + +Description +----------- + +This system call returns filtered data, which might be section or Packetized +Elementary Stream (PES) data. The filtered data is transferred from +the driver’s internal circular buffer to ``buf``. The maximum amount of data +to be transferred is implied by count. + +.. note:: + + if a section filter created with + :c:type:`DMX_CHECK_CRC <dmx_sct_filter_params>` flag set, + data that fails on CRC check will be silently ignored. + +Return Value +------------ + +On success 0 is returned. + +On error -1 is returned, and the ``errno`` variable is set +appropriately. + +.. tabularcolumns:: |p{2.5cm}|p{15.0cm}| + +.. flat-table:: + :header-rows: 0 + :stub-columns: 0 + :widths: 1 16 + + - - ``EWOULDBLOCK`` + - No data to return and ``O_NONBLOCK`` was specified. + + - - ``EOVERFLOW`` + - The filtered data was not read from the buffer in due time, + resulting in non-read data being lost. The buffer is flushed. + + - - ``ETIMEDOUT`` + - The section was not loaded within the stated timeout period. + See ioctl :ref:`DMX_SET_FILTER` for how to set a timeout. + + - - ``EFAULT`` + - The driver failed to write to the callers buffer due to an + invalid \*buf pointer. + +The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. |