iecset

iecset [options] [value]
or
iecset [-h]

-p
    Specify the 1394 OHCI port number.

-d
    Specify the 1394 character device file (e.g., /dev/fw0).

-i
    Specify the input plug number (IT_PLUG).

-o
    Specify the output plug number (OT_PLUG).

-c
    Set or get the ISOCHRONOUS channel number.

-t
    Set or get the transfer rate (e.g., 100, 200, 400 Mbps).

-m
    Set or get the operation mode. Valid modes are source or sink.

-v
    Enable verbose output.

-q
    Enable quiet output, only report values.

-h
    Display the help message and exit.

iecset is a command-line utility used to manage and query the data transfer parameters for IEC 61883-4 compliant devices connected via IEEE 1394 (FireWire). These devices often include digital camcorders, VCRs, and other audiovisual equipment that utilize FireWire for transferring MPEG2-TS (Transport Stream) data.

The command allows users to configure aspects like the data transfer channel, input/output plugs, transfer rate, and operational mode (source or sink). When run without arguments, iecset displays the current settings. When provided with options and values, it attempts to set those parameters on the specified FireWire device or port. This tool is fundamental for applications requiring direct control over FireWire video capture or playback streams.

iecset directly interacts with low-level FireWire drivers. Misconfiguration can lead to data transfer issues or a device not being recognized correctly by applications. It typically requires root privileges or appropriate group permissions to access /dev/fw* devices. This command is highly specific to IEEE 1394 (FireWire) devices and is not applicable to USB or other interface types.

iecset can be used to query the current state of a FireWire device by running it without arguments, for example, iecset -d /dev/fw0. To set specific parameters, options are combined, such as iecset -d /dev/fw0 -m source -c 63 to configure a device as a source on channel 63.

The IEC 61883 standard specifies the digital interface for consumer audio/video equipment, ensuring interoperability between devices from different manufacturers. Part 4 (IEC 61883-4) specifically deals with the transfer of MPEG-2 Transport Stream data over the IEEE 1394 interface. iecset directly manipulates parameters related to this standard.

iecset is part of the libiec61883 library, which provides support for the IEC 61883 standard (digital interface for consumer audio/video equipment). This standard is primarily used over IEEE 1394 (FireWire). Development of libiec61883 and associated tools like iecset has been driven by the need to interact with DV camcorders and other FireWire-based A/V equipment on Linux, especially in the early 2000s when FireWire was prevalent for video capture and digital archiving.

dvgrab(1), ffado-test(1), raw1394(4)