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.. -*- coding: utf-8; mode: rst -*-
.. _dmx_fread:
=======================
Digital TV demux read()
=======================
Name
----
Digital TV demux read()
Synopsis
--------
.. c:function:: size_t read(int fd, void *buf, size_t count)
:name: dvb-dmx-read
Arguments
---------
``fd``
File descriptor returned by a previous call to :c:func:`open() <dvb-ca-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 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}|
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- - ``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.
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