Convert SDS to MIDI

A sampler or archive may provide an .sds sample when a DAW or notation program requires editable MIDI. Because SDS carries sampled audio and MIDI carries performance events, the practical conversion is either exporting the sample or analyzing it to estimate notes.

What the SDS format is

MIDI Sample Dump Standard (SDS) is a MIDI-based protocol for transferring sampled audio between hardware samplers, computers, and sample editors. An .sds file usually represents an SDS sample dump or a program-specific recording of that dump; it is not a Standard MIDI File.

SDS data can include the waveform and parameters such as sample number, sample period or rate, bit depth, sample length, root MIDI note, tuning, and sustain-loop positions. Older samplers and specialist audio utilities are the main sources of these files. SDS normally contains no sequence of note pitches, durations, velocities, or channel events.

What the MIDI format is

A Standard MIDI File uses the .mid or .midi extension and stores timestamped events such as note-on, note-off, velocity, controller, program-change, tempo, and time-signature messages. It stores instructions rather than the recorded waveform, so files are compact and their notes can be edited, transposed, quantized, or assigned to different instruments.

MIDI can trigger an audio sample loaded in a sampler, but an ordinary MIDI file cannot carry an SDS waveform as an equivalent audio replacement. Playback also depends on the receiving synthesizer or sampler; MIDI does not guarantee the original sound.

How to convert an SDS sample

First export the sample to audio. This preserves the source material and is the correct result when the goal is playback, editing, or archiving.

1. Make a copy of the .sds file and open it in a utility that supports SDS, such as Awave Studio on Windows. Support can vary between SDS dump variants, so confirm that the program identifies a sample rather than treating the file as unknown data.
2. Check the decoded sample rate, bit depth, length, root note, tuning, and loop start and end points. Compare the duration and pitch with the original sampler when possible.
3. Use File → Save As, export, or the program's batch-conversion function to write .wav or .aiff. WAV is generally the most compatible choice for DAWs and samplers.
4. Load the exported audio into the destination sampler, re-enter the root note and loop settings, and create a MIDI track that triggers it. This produces MIDI control while retaining the original sampled sound.

Other specialist applications, including sampler-format translators such as Chicken Systems Translator, may read particular SDS variants. Verify current format support and test a representative file before converting a collection.

How to create editable MIDI notes

Use audio-to-MIDI transcription only if the sample contains a pitched phrase or performance and editable notes are required. It is not a lossless format conversion.

1. Open the exported WAV in Celemony Melodyne, choose the Melodic algorithm for monophonic material or an appropriate polyphonic algorithm, and use File → Export → MIDI. MIDI export availability depends on the Melodyne edition.
2. As a free desktop alternative, run Spotify's open-source Basic Pitch with basic-pitch output_folder input.wav. It creates a MIDI file from its estimated pitches, note starts, durations, and velocities.
3. Import the resulting .mid into the DAW and correct false notes, octave errors, note boundaries, velocities, and timing. Quantize only after checking the transcription against the audio.

There is no generally reliable one-click online SDS-to-MIDI service. Online audio-to-MIDI transcription services can sometimes process the exported WAV, but they cannot recover notes that are absent from the sample and require uploading the audio. Do not upload unpublished or restricted material unless the service's storage and licensing terms are acceptable.

Quality and compatibility limits

Decoding SDS to WAV is normally a format conversion; creating MIDI requires audio analysis. Monophonic material with clear attacks produces better results than chords, drums, noise, reverberation, heavily processed sounds, or recordings containing multiple instruments.

Sampler-specific behavior may not survive a WAV export. Preserve the original root note, tuning, loop points, loop type, playback direction, and envelope settings, then reproduce them in the destination sampler. Different software may interpret sample-rate, bit-depth, loop, or end-point conventions differently.

SDS transfer messages can be embedded in MIDI System Exclusive data, but that is a hardware dump, not a MIDI note sequence. Such a file is useful only with compatible sampler hardware or software and will not make the sampled audio editable as ordinary MIDI notes.