How Ecasound Handles Audio Metadata and Tags

Ecasound treats audio strictly as a continuous stream of digital signal samples, which means it completely discards file metadata tags such as ID3, Vorbis comments, and extended RIFF headers during processing. Because its architecture is built around routing, transforming, and mixing raw pulse-code modulation (PCM) data rather than managing multimedia file containers, Ecasound does not extract, store, or forward non-audio data to output files.

The Signal-Processing Pipeline

Ecasound functions similarly to a hardware console or a modular digital audio workstation (DAW). When an input file—such as a FLAC, MP3, or WAV—enters the Ecasound engine, the application uses internal routines, libsndfile, or external helper utilities (like LAME or Oggdec) to strip the container format and decode the payload directly into a raw sample stream.

Once decoded:

Audio data is placed into internal processing buffers as linear PCM samples.
The metadata headers (artist, album, track number, track gain, or replay gain tags) are completely ignored and stripped away at the decoding boundary.
All DSP chains, filters, envelopes, and panning operations occur entirely within this sample-only domain.

Output File Generation and Missing Tags

When the audio reaches the output stage, Ecasound formats the processed PCM stream back into the specified container format (such as writing a new .wav or .flac file). Because the internal routing matrix has no mechanism to carry key-value pairs or text attributes:

Target files are created containing only the structural headers required by the audio format specification (sample rate, bit depth, channel count, and payload size).
Non-audio chunks (such as LIST-INFO or ID3 chunks inside WAV containers) are omitted.
Encoded compressed files (such as MP3 or Ogg Vorbis) receive fresh, blank headers with zero metadata fields populated.

Ecasound possesses no built-in command-line switches, routing operators, or .ecasoundrc configuration parameters to instruct the engine to transfer metadata from an input object to an output object.

Workarounds for Tag Preservation

Because Ecasound will not retain metadata on its own, automated workflows and scripts must treat metadata management as a separate, external stage.

Extract Metadata Prior to Processing: Use an external tool like ffprobe, exiftool, or format-specific readers (such as metaflac or id3v2) to export existing tags to a temporary file or environment variables.
Process Audio via Ecasound: Run the Ecasound command to process the audio stream, outputting a completely untagged destination file.
Re-apply Metadata Post-Processing: Inject the saved metadata into the newly created audio file using tools like mid3v2, vorbiscomment, metaflac, or ffmpeg.

By separating metadata persistence from signal manipulation, you can utilize Ecasound for complex DSP, filtering, and multitrack routing without permanently losing file-level track details.