How to Handle SGMCA, FTR & BWF Court Recordings Safely

Someone sends you courtroom audio and none of the files open. The folder may contain .sgmca, a run of numbered .trm files, a .bwf, or several sidecars with names that look disposable. The hearing happened and the recording exists; the problem is that the delivery format assumes you still have the system that created it.

The safe goal is not to “fix” that delivery. It is to preserve it, make a separate playable derivative, and leave enough notes that another person can reproduce what you did.

This is a technical workflow, not legal advice or a universal evidence-handling rule. Court orders, agency policy, client instructions, and local procedure control. If the recording may be evidence, confirm the required process before converting or distributing anything.

Before you open anything

1. Keep the complete delivery together. Do not discard files just because they are small or unfamiliar. A sidecar can carry timing, channel, annotation, or session information.
2. Preserve an untouched source copy. Copy the delivered folder to controlled storage and do not convert in place. If your organization has a formal evidence or records workflow, use it.
3. Create a separate working folder. Do all playback, conversion, cleanup, and renaming there.
4. Record what you received. At minimum, note the source, receipt date, original filenames, file sizes, and who performed the conversion. Use your organization’s formal intake or chain-of-custody process when one applies.

Identify the package, not just the extension

An extension is a clue, not proof. Keep all related files until you know how the session is organized.

SGMCA

SGMCA is associated with Stenograph and Case CATalyst. The variants currently supported by DepoAudio contain Ogg Vorbis audio behind a proprietary header, which is why an ordinary player may reject a file even though the audio payload uses a known codec. Do not manually trim bytes from the only copy; use a duplicate and a tool that identifies the structure before converting it.

FTR and TRM

For The Record calls TRM its native recording format. A court delivery will often contain a sequence of .trm files rather than one long recording. FTR’s legacy player documentation explains that its recorder commonly writes five-minute blocks, so opening only one segment can make a complete session look truncated. Keep the numbered set together and import it in order. The current FTR Player remains the vendor-supported playback route; a local converter is useful when you need a standard working format or macOS access.

BWF

Broadcast Wave Format is not merely “a WAV with a different extension.” The EBU specification defines a RIFF/WAVE file with a broadcast audio extension and permits metadata and additional chunks that ordinary consumer software may ignore. BWF can carry PCM or MPEG audio, and related files may form a linked set. A plain-WAV export can be useful for listening or editing, but it may not retain every metadata field from the source.

Convert a working copy with DepoAudio

DepoAudio is the free, open-source app I built for this exact gap. It identifies supported SGMCA, BWF, and standard media locally; the recording is not uploaded for conversion. FTR/TRM conversion is currently experimental because variants differ, so treat detection as a starting point rather than proof that a session converted correctly. Use FTR Player or the originating system’s approved export route when DepoAudio cannot identify the variant or the result does not verify cleanly.

The workflow is the same on Windows and macOS:

1. Download the current release from the DepoAudio install guide and review any platform installation notice.
2. Drag files from the working folder, not the preserved source, into the converter. If you are testing an FTR variant that DepoAudio identifies, add every numbered TRM segment together; otherwise use FTR Player or the originating system’s approved export route.
3. Confirm that the detected format and file order match what you received. Stop if the app reports an unsupported or ambiguous format.
4. Choose an output intentionally:
   • PCM WAV for a broadly compatible, uncompressed working copy.
   • FLAC for lossless compression when the next tool supports it.
   • MP3, M4A/AAC, or Opus only when smaller delivery files are appropriate; these outputs use lossy encoding. M4A/AAC is the M4A option documented for DepoAudio v1.0.2.
5. Preserve separate channels when speaker isolation matters. A stereo mix is convenient, but mixing channels together removes options you may need during transcription or review.
6. Export to a new destination. Do not overwrite the received files.

DepoAudio is a conversion and review utility, not a substitute for an evidence-management system. Its output should be treated as a derivative whose purpose and settings are documented.

September 4, 2026 clarification: M4A names a container, not a single codec. It can hold AAC or lossless ALAC; WAV can also hold codecs other than PCM. These output labels follow the DepoAudio guide. Apple’s Core Audio format table documents the container/codec distinction. Check the actual encoding rather than inferring it from the extension.

Verify the result

“The progress bar finished” is not verification. Before handing off the derivative:

• Compare the expected and exported durations.
• Listen near the beginning and end, plus a sample from the middle.
• Confirm that every FTR segment appears in the correct order.
• Check each channel for actual audio, silence, duplication, or swapped speaker labels.
• Retain the original filenames in your inventory even if the working files receive clearer names.
• Record the tool version, output format, channel choice, cleanup settings, destination, date, and operator.

If you apply denoise, leveling, de-clipping, trimming, or channel mixing, keep that output separate from the straight conversion. A cleaned listening copy can be useful without being confused with the first derivative.

What conversion can change

Troubleshooting

The FTR recording is only five minutes long. You probably opened one TRM segment. Return to the delivery folder and import the complete numbered run.

The file extension says WAV, but a player rejects it. Do not rename or rewrite the source. Identify its actual container and codec from a working copy; extensions are not reliable proof.

A BWF plays, but its timestamps or annotations are missing elsewhere. The receiving application may ignore broadcast or private metadata chunks. Preserve the original BWF and any sidecars even when the audio derivative sounds correct.

One participant is inaudible. Inspect the individual channels before applying gain or making a mix. The quiet microphone may exist on a separate channel rather than being absent.

The app says the variant is unsupported. Stop experimenting on the source. Use the originating vendor’s export route or provide a non-sensitive sample through the project’s documented issue process. Proprietary formats can change without changing their extension.

The short version

Preserve the received package. Work from a copy. Import complete sessions, especially numbered TRM sets. Choose output and channel handling deliberately. Verify the result, document the conversion, and keep source, straight derivative, and cleaned listening copy distinct.

For the larger capture-to-certified-record workflow, read Digital Court Reporting: From Capture to Certified Transcript. For the design decisions behind the converter, see DepoAudio: Getting Court Audio Out of Jail and Why I Open-Sourced DepoAudio.