RawAudio

A single block of an audio bitstream

Panel support

RawAudio is used in the Audio panel.

Schema

field	type	description
timestamp	Timestamp	Timestamp of the start of the audio block
data	bytes	Raw audio data without WAV, container, or RTP headers. Samples must be interleaved. Multibyte samples must be little-endian.
format	string	Format of the audio data. See the data field description for supported values. Consumers may support a subset of these formats.
sample_rate	uint32	Sample rate in Hz. This must be greater than zero.
number_of_channels	uint32	Number of channels in the audio block. This must be greater than zero.

data

For each format value, the data field contains audio sample data serialized as follows:

• pcm-s16:
  • Each sample is a signed 16-bit PCM value.
  • The byte length must be divisible by 2 * number_of_channels so the block contains complete sample frames.
• g711-alaw:
  • Each byte is one G.711 A-law encoded sample.
  • The byte length must be divisible by number_of_channels so the block contains complete sample frames.
• g711-ulaw:
  • Each byte is one G.711 mu-law encoded sample.
  • The byte length must be divisible by number_of_channels so the block contains complete sample frames.

Reference implementations

Foxglove messages are framework-agnostic, and can be implemented using any supported message encoding:

encoding	schema
ROS 1	foxglove_msgs/RawAudio
ROS 2	foxglove_msgs/msg/RawAudio
JSON	foxglove.RawAudio
Protobuf	foxglove.RawAudio
FlatBuffers	foxglove.RawAudio
OMG IDL	foxglove::RawAudio

You must use the schema names specified above for Foxglove to recognize the schema.