3.2.3. Digital TV demux read() Name

Digital TV demux read() Synopsis

size_t read(int fd, void *buf, size_t count) Arguments

File descriptor returned by a previous call to open().
Buffer to be filled
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.


if a section filter created with DMX_CHECK_CRC 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.

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 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 Generic Error Codes chapter.