Dpdo

FLAC to DSD Tutorial: From Lossless PCM to DSD64/128

FLAC is a lossless container for PCM — it is not DSD. Converting FLAC to DSD (DSF/DFF) requires the full resampling + noise shaping + modulation pipeline. Here are ready-to-run commands.

1. What actually happens when you convert FLAC to DSD

A FLAC file contains PCM data (typically 16/24-bit, 44.1–192 kHz). Converting to DSD means:

  1. Decompress: FLAC → raw PCM samples
  2. Resample: PCM rate → DSD rate (44.1 kHz × 64 = 2.8224 MHz / DSD64)
  3. Noise shape: multi-bit → 1-bit quantization, pushing quantization noise to the ultrasonic band
  4. Package: output as DSF or DFF

The conversion maps a lossless source to a high-precision target — all information in the FLAC is preserved (resampling changes representation, not data), but no extra detail is conjured out of thin air.

2. Option A: direct command-line conversion (single file, full control)

# FLAC → DSF (DSD64, default 7th-order IIR)
	DpdoEngine -i track.flac track.dsf --oversampling 64
	
	# FLAC → DFF (DSD128, 11th-order IIR, in-band noise floor pushed furthest)
	DpdoEngine -i track.flac track.dff --oversampling 128 --order 11
	
	# FLAC → DSF (DSD256 + OpenCL acceleration + album metadata + report)
	DpdoEngine -i track.flac track.dsf --oversampling 256 \
	  --opencl --report --artist "Artist" --album "Album" --year "2026"

Parameter quick reference: - --oversampling N: oversampling ratio (64=DSD64, 128=DSD128, 256=DSD256) - --order N: IIR noise shaping order (3/5/7/9/11, default 7) - --opencl: GPU acceleration (OpenCL 1.2+) - --report: generate an analysis report - --metadata-from-input: auto-extract metadata from the source file (overridable by explicit flags) - --reverse: reverse direction (DSD → PCM)

3. Option B: batch conversion (whole album, one command)

Use the convert batch script shipped with the release (requires ffmpeg + DpdoEngine):

# Enter the directory containing FLAC files, batch-convert to DSF (DSD64)
	cd album-directory
	bash convert flac2dsf
	
	# Specify output rate (example: DSD128)
	bash convert flac2dsf 128

Supported conversion types:

PCM/PCM:   wav2flac, flac2wav, m4a2flac
	DSD/PCM:   dsf2flac, dsf2wav, dff2flac, dff2wav
	PCM→DSD:   wav2dsf, wav2dff, flac2dsf, flac2dff
	PCM→DXD:   wav2dxd_w64, wav2dxd_wav, wav2dxd_flac, flac2dxd_*

4. Verifying the result

# Measure distortion and noise floor of the output DSD file (THD+N)
	thdn track.dsf
	
	# Compare in-band performance of different noise shaping orders
	dsp_bench --input test.flac --order 9 --order 11

What to check: - In-band (20 Hz–20 kHz) noise floor meets expectations (DSD64 theoretical SNR is on the order of 120 dB; actual depends on shaping order) - Frequency-response consistency with the original PCM (did the resampling filter introduce audible deviation?) - Actual listening through your DAC/player (the playback chain is the final judge)

5. FAQ

Does the FLAC source rate matter? 44.1 kHz sources convert perfectly well; 96/192 kHz sources are even more comfortable at DSD128+ (less interpolation error).

Can the output go straight into SACD authoring? Yes. Feed the DSF/DFF output directly to DpdoPackSACD to build a SACD ISO (see the authoring tutorial).

Batch conversion is slow — what can I do? Enable --opencl (GPU acceleration), or lower the order (7th-order IIR is real-time friendly on modest hardware).

Written by Dpdo. Commands verified against DpdoEngine 6.68 and the release convert script.