11. The modulator is made by a quantizer which converts the difference between the input signal and the average of the previous steps. 12. The use of this approximation can allow the entropy coding design problem to be separated from the design of the quantizer itself. 13. However, it must be used with care : this derivation is only for a uniform quantizer applied to a uniform source. 14. Constant quantizer encoding can be used, however, to accurately determine the minimum and maximum bitrates possible for encoding a given video. 15. In such cases, using a mid-tread uniform quantizer may be appropriate while using a mid-riser one would not be. 16. However, for a source that does not have a uniform distribution, the minimum-distortion quantizer may not be a uniform quantizer. 17. However, for a source that does not have a uniform distribution, the minimum-distortion quantizer may not be a uniform quantizer . 18. Contrary to popular belief, a fixed frame-level quantizer ( set by the user ) does not deliver a constant level of quality. 19. The extent of the reduction may be varied by changing the quantizer scale code, taking up much less bandwidth than a full quantizer matrix. 20. The extent of the reduction may be varied by changing the quantizer scale code, taking up much less bandwidth than a full quantizer matrix.
