A few years ago I wrote about how to extract the audio using the obsolete Windows program DVD-Audio Explorer. I wanted to be able to run the extraction via the command line, which means trying to find a native Linux app. I tried Python AudioTools but I got lost in an endless maze of incompatible dependencies.

So I went with Brian "tuffy" Langenberger's libDVD-Audio.

To install, simply run:

sudo make install

That will give you two new programs. To get info about your DVDA, run:

dvda-debug-info -A /path/to/your/AUDIO_TS

That will pump out details about each track like so:

Title  Track  Length  PTS Length  First Sector  Last Sector
    1      1    3:30    13450000             0        86547
    1      2    4:11    12500000         73144       122600
    1      3    2:11    16010000        370601       233337

Extract

To extract the tracks, run:

dvda2wav -A /path/to/your/AUDIO_TS

That will spit out the files in WAV format.

Encode

WAV is pretty large - about 20MB per minute per channel. Converting to FLAC (the Free Lossless Audio Codec) gets you down to about 10MB. I just go straight for the modern Opus Codec which does excellent quality surround sound at low file sizes.

opusenc --bitrate 4096 track-01-01.wav 1.opus

That's about 2MB/minute/channel and I promise that you won't hear the difference.

Metadata

If you want to add metadata to a track, it's done like this:

opusenc --bitrate 4096 in.wav out.opus --title "Yesterday" --artist "The Beatles" --tracknumber "02"

Older versions of Opusenc, oddly, don't have a native way to express track numbers, so you'll need to do it manually using --comment "tracknumber=02"

Newer versions can use --tracknumber to add track numbers.

Automating

You can make it slightly easier to add the metadata if you give the files predictable names. For example: 01-Yesterday-The Beatles.wav

Here's a scrappy bash script:

#!/bin/bash
for FILE in *.wav
do
    FILENAME="${FILE%.*}"

    TRACK=$(echo  $FILENAME | cut -d'-' -f 1)
    TITLE=$(echo  $FILENAME | cut -d'-' -f 2)
    ARTIST=$(echo $FILENAME | cut -d'-' -f 3)

    OUTPUT="[$TRACK] $ARTIST - $TITLE.opus"

    opusenc --bitrate 4096 "$FILE" "$OUTPUT" --title "$TITLE" --artist "$ARTIST" --tracknumber "$TRACK"
done

I hope future me finds these notes useful!