RF Compression Notes editing - oyvindln/vhs-decode GitHub Wiki

Down-sampling + FLAC Compression (Windows Commands)

Untill piping or scripting is sorted out properly these commands will live here, as not to clutter main docs or cause help issue requests.

NTSC - VHS/Betamax (16msps 8-bit)

C:\ld-tools-suite-windows\ld-lds-converter.exe -i INPUT.lds | sox -r 40000000 -b 16 -c 1 -e signed -t raw - -b 8 -r 16000000 -e unsigned -c 1 -t raw - sinc -n 2500 0-7650000 | flac -8 --sample-rate=16000 --sign=unsigned --channels=1 --endian=little --bps=8 - -o OUTPUT_NTSC_16msps_8-bit.flac

PAL - VHS/BetaMax (18msps 8-bit)

C:\ld-tools-suite-windows\ld-lds-converter.exe -i INPUT.lds | sox -r 40000000 -b 16 -c 1 -e signed -t raw - -b 8 -r 18000000 -e unsigned -c 1 -t raw - sinc -n 2500 0-8800000 | flac -8 --sample-rate=17000 --sign=unsigned --channels=1 --endian=little --bps=8 - -o OUTPUT_PAL_18msps_8-bit.flac

NTSC/PAL - Umatic/SVHS/SuperBeta/ED-Beta (24msps 8-bit)

C:\ld-tools-suite-windows\ld-lds-converter.exe -i INPUT.lds | sox -r 40000000 -b 16 -c 1 -e signed -t raw - -b 8 -r 24000000 -e unsigned -c 1 -t raw - sinc -n 2500 0-9400000 | flac -8 --sample-rate=20000 --sign=unsigned --channels=1 --endian=little --bps=8 - -o OUTPUT_24msps_8-bit.flac

HiFi FM Audio

C:\ld-tools-suite-windows\ld-lds-converter.exe -i INPUT.lds | sox -r 40000000 -b 16 -c 1 -e signed -t raw - -b 8 -r 10000000 -e unsigned -c 1 -t raw - sinc -n 2500 0-3050000 | flac -8 --sample-rate=10000 --sign=unsigned --channels=1 --endian=little --bps=8 - -o OUTPUT_HiFi.flac

Tools

Make a spectrum graph with SoX

sox input.u8 -n spectrogram