Crate ta1394_avc_audio 

The crate includes Rust elements for the part of protocol defined by 1394 Trading Association (1394 TA).

Protocol documentation

The protocol is documented in:

• AV/C Audio Subunit Specification 1.0 (Oct. 24, 2000, 1394 Trading Association, TA Document 1999008)
• Audio and Music Data Transmission Protocol 2.3 (Apr. 24, 2012, 1394 Trading Association, Document 2009013)

1394 TA was formed 1994 and decided to close its official operation 2015. As of 2021, it has been dissolved and close its web site under URL http://1394ta.org in the end of year.

The document is itself available at Internet Archive service when seeking URL http://1394ta.org/specifications/ with enough care of cached date.

Usage

Add the following line to your Cargo.toml file:

[dependencies]
ta1394-avc-audio = "0.2"

The crate consists of two parts; some AV/C commands and FDF format of A/M packet.

AV/C commands

Some documented AV/C commands are available:

• AudioSelector (clause “10.2 Selector function block”)
• AudioFeature (clause “10.3 Feature function block”)
• AudioProcessing (clause “10.4 Processing function block”)

The commands should be given to implementation of Ta1394Avc trait provided in ta1394-avc-general crate to perform AV/C operation.

FDF format

The AmdtpFdf structure is provided to build and parse &u8 for some events of Audio and Music Data Transmission protocol.

License

The crate is released under MIT license.

Support

If finding issue, please file it in https://github.com/alsa-project/snd-firewire-ctl-services/.

Contribution

If intending for code contribution, I would like the user and developer to take care of some points before working.

It’s well-known that the association promoted by several vendors tends to publishes specifications and documentations with over-engineering for several reasons; e.g. rat race in business or market. Beside the risk to include bug is exponentially increased when the code base is larger and larger. It’s not preferable for your work just to fulfill whole the specifications and documentations.

The point is that there is actual requirement for the new code. For example, the crate includes some AV/C commands to satisfy requirement of snd-firewire-ctl-services project. It’s preferable for you to have actual application using the new code.

Modules

amdtp

Encoder and decoder of FDF field in Audio and Music Data Transmission Protocol.

Structs

AudioFeature

AV/C Audio Subunit FUNCTION_BLOCK command for Feature function block

AudioProcessing

AV/C Audio Subunit FUNCTION_BLOCK command for processing function block

AudioSelector

AV/C Audio Subunit FUNCTION_BLOCK command for Selector function block

BassData

Parameters for bass control.

DelayData

Parameters for delay.

FrBalanceData

Parameters for Front-to-Rear balance.

GraphicEqualizerData

Parameters for graphic equalizer.

LrBalanceData

Parameters for Left-to-Right balance.

MidData

Parameters for mid control.

TrebleData

Parameters for treble control.

VolumeData

Parameters for volume.

Enums

AudioCh

For the value of audio_channel_number field described in clause “10.3 Feature function block”.

CtlAttr

For attributes of control (clause “4.8 Control Attributes”).

FeatureCtl

The type of Feature Control.

ProcessingCtl

The type of processing control.

Constants

AUDIO_SUBUNIT_0_ADDR

The AV/C address of first music subunit for convenience.