Migrating from 0.30 to 0.31

CLI

MCAP "layers" renamed to "decoders"

The -l / --layer flag for rerun mcap convert has been renamed to -d / --decoder.

This change is motivated by the ambiguity of the term "layer", which is also a core concept of Rerun Cloud.

Before:

rerun mcap convert input.mcap -l protobuf -l stats -o output.rrd
rerun mcap convert input.mcap -l ros2msg -l raw -l recording_info -o output.rrd

After:

rerun mcap convert input.mcap -d protobuf -d stats -o output.rrd
rerun mcap convert input.mcap -d ros2msg -d raw -d recording_info -o output.rrd

When no -d flags are specified, all available decoders are still used by default (same behavior as before).

Rust API

re_mcap: Layer types renamed to Decoder

All public types in the re_mcap crate have been renamed from Layer to Decoder.

The layers module has been renamed to decoders (e.g., re_mcap::layers::McapRawLayer is now re_mcap::decoders::McapRawDecoder).

McapLoader API updated

McapLoader::new() now takes SelectedDecoders instead of SelectedLayers:

// Before
McapLoader::new(SelectedLayers::All)

// After
McapLoader::new(SelectedDecoders::All)