3.2.1. Digital TV demux open() Name

Digital TV demux open() Synopsis

int open(const char *deviceName, int flags) Arguments


Name of specific Digital TV demux device.


A bit-wise OR of the following flags:


read-only access


read/write access


open in non-blocking mode (blocking mode is the default) Description

This system call, used with a device name of /dev/dvb/adapter?/demux?, allocates a new filter and returns a handle which can be used for subsequent control of that filter. This call has to be made for each filter to be used, i.e. every returned file descriptor is a reference to a single filter. /dev/dvb/adapter?/dvr? is a logical device to be used for retrieving Transport Streams for digital video recording. When reading from this device a transport stream containing the packets from all PES filters set in the corresponding demux device (/dev/dvb/adapter?/demux?) having the output set to DMX_OUT_TS_TAP. A recorded Transport Stream is replayed by writing to this device.

The significance of blocking or non-blocking mode is described in the documentation for functions where there is a difference. It does not affect the semantics of the open() call itself. A device opened in blocking mode can later be put into non-blocking mode (and vice versa) using the F_SETFL command of the fcntl system call. Return Value

On success 0 is returned.

On error -1 is returned, and the errno variable is set appropriately.


“Too many open files”, i.e. no more filters available.

The generic error codes are described at the Generic Error Codes chapter.