Variable Bitrate

Discussion in 'CloneBD' started by bphem3, May 30, 2021.

  1. bphem3

    bphem3 Member

    Does anyone know if CloneBD will receive an encoding option for variable bitrate?
  2. DeepSpace

    DeepSpace Well-Known Member

  3. Fabian

    Fabian Developer

    The used AAC encoder already has variable bitrate.

    You may think of the old MP3 audio codec which added a feature for variable bitrate, meaning each audio frame adjusted its size to use the least size for same quality. With AAC, this feature is always implicit, it always behaves the same as the variable bitrate MP3.

    For E-AC3 or DTS, this feature will not work. Both encoders would reset its internal state upon bitrate change. It would lead to noticeable audio artifacts. While it is possible to change that, it wouldn't change all the audio decoders that still will reset upon bitrate change.
  4. bphem3

    bphem3 Member

    whatever_gong82 likes this.
  5. Fabian

    Fabian Developer

    My apologies, I assumed you were talking about audio variable bitrate; that's at least what my mind was thinking about.

    We will actually add an option to encode quality based. With quality based encoding the output size is not predictable, but for a selected quality the file size will be minimal. The technical term is CRF encoding.
    whatever_gong82 and DeepSpace like this.