Note: Some of these things might have already been implemented. But many aren't yet.

* fixed Bitrate-Support
* Wav-Reader
* Samplerates != 44100
* Non-Linear-PCM-Support?
* SV8
* Divide Frontend and Encoder

* Subbandfilter in 3DNow!
* New Replayfilter
* diffuse field equalisation
* different ATH table
* Checksum between end of MPC audio and ID3V1.1-Tag (32 bit or 128 bit)
* 11 bit in header, to determine the file length from the header
* 2 bit: No Start with Silence/No End with silence for random play

- Total length of the source WAV should be noted in the header
- Maximum level of the track during decoding
- Maximum level of the CD during decoding (if not continuous)
- MD5 hash over the whole file (except private settings)
- private level settings in the file (e.g. -327.68 ... +327.67 dB), if tracks are played individually
- private level settings in the file (e.g. -327.68 ... +327.67 dB), if albums (without shuffle) are played
- Minimum play length: 4 hours
- Bitrate for every kind of music below 256 kbps (2 channel) and 512 kbps (5 channel)
- Lossless cutting in every place (small increase of total data size is allowed)
- Lossless joining (small increase of total data size is allowed)
- Playlist management: mppdec myhits.mpl /dev/audio
- For streaming: Send track info + encoder info at the beginning and at the end (like on MTV)
- Forward and rewind should be possible with arbitrary long files
- Support of 32 kHz, 44.1 kHz, 48 kHz
- Support of 1...8 channels
- Save the most characteristic spots (ca. 5 s, ca. 15 s, ca. 1 min)
- Don't fade the audio data directly, but save it as a multiplicator per frame
  and use that during playback (-1 = leave out, 0 = silence,
  1...253 fade, 254 normal volume)  
  Status of that data: Never use, only with Shuffle Play, always use
- Sample-exact index markers with title-specific information