---
name: "fwdv"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/fwdv"
---

# fwdv(4)

AV/C DV capture driver for FireWire camcorders

## NAME

**fwdv** – AV/C DV capture driver for FireWire camcorders

## SYNOPSIS

**device firewire** **device fwdv**

## DESCRIPTION

The **fwdv** driver provides DV frame capture from AV/C tape devices attached via IEEE 1394 (FireWire), including DV camcorders, VCRs, and DV converters.

The driver attaches to unit directories in the device CSR configuration ROM with *unit\_spec\_id* 0x00a02d (1394 Trade Association) and *unit\_sw\_version* 0x010001 (AV/C). When a matching device is present on the [firewire(4)](/firewire/4.md) bus, the driver creates */dev/fwdvX* and begins receiving IEC 61883 isochronous packets on first open, assembling complete DV frames. Applications read raw DV frames from the character device and control tape transport through [ioctl(2)](/ioctl/2.md).

Both NTSC and PAL SD-DV streams are detected from the incoming CIP header. DVCPRO HD frame sizing is also recognized.

## IOCTLS

- FWDV\_GINFO (*struct fwdv\_info*)

  Return driver state, active ISO channel, detected DV system, frame size, frame counters, dropped frame count, device EUI-64, and vendor/model strings from the device configuration ROM.

- FWDV\_PLAY

  Send the AV/C play command to tape subunit 0.

- FWDV\_STOP

  Send the AV/C stop command to tape subunit 0.

- FWDV\_FFWD

  Send the AV/C fast-forward command to tape subunit 0.

- FWDV\_REW

  Send the AV/C rewind command to tape subunit 0.

## SYSCTLS

- *hw.firewire.fwdv.iso\_channel*

  Fallback isochronous receive channel. The default is 63. If the device output plug control register reports an active channel, that device-reported channel is used instead. This value can be set as a tunable in [loader.conf(5)](/loader.conf/5.md).

## FILES

- */dev/fwdvX*

  DV capture character device. Read to obtain raw DV frames.

## SEE ALSO

[firewire(4)](/firewire/4.md), [fwohci(4)](/fwohci/4.md)

AV/C Digital Interface Command Set General Specification 4.1, 1394 Trade Association Document 2001012.

IEC 61883-1 and IEC 61883-2.

## HISTORY

The **fwdv** driver first appeared in FreeBSD 16.0.

## AUTHORS

Abdelkader Boudih ⟨*freebsd@seuros.com*⟩