- Two 48 kHz wav files that are supposed to be played consecutively (let's not go to 44.1 kHz for now)
- Two corresponding .opus encoded files (using opusenc)
- The two decoded opus files as wav (using opusdec)
- The same (.ogg and decoded wav) for Vorbis
Make sure you use opusenc and opusdec. All the gapless handling is done by the actual tools rather than the Opus library and not all encoders and decoders are going a good job at gapless.