• Rostislav Pehlivanov's avatar
    aacenc: add support for encoding files using Long Term Prediction · 27d23ae0
    Rostislav Pehlivanov authored
    Long Term Prediction allows for prediction of spectral coefficients
    via the previously decoded time-dependent samples. This feature
    works well with harmonic content 2 or more frames long, like speech,
    human or non-human, piano music or any constant tones at very low
    bitrates.
    
    It should be noted that the current coder is highly efficient and
    the rate control system is unable to encode files at extremely
    low bitrates (less than 14kbps seems to be impossible) so this
    extension isn't capable of optimum operation. Dramatic difference
    is observable with some types of audio and speech but for the most
    part the audiable differences are subtle. The spectrum looks better
    however so the encoder is able to harvest the additional bits that
    this feature provies, should the user choose to enable it. So
    it's best to enable this feature only if encoding at the absolutely
    lowest bitrate that the encoder is capable of.
    27d23ae0
aacenc_ltp.c 7.89 KB