d*******n
发帖数: 369 | 1 For MP1 and MP2, 假设input frame is 512 samples. after it is fed into 32个
bandpass PQMF filter， the output is 512 spectral components grouped into 32
banks or 512 time-domain samples?
Since the input is time-domain samples, the output of the bandpass filters
should be also time-domain samples, right? If so, quantizer will take the
output of the bandpass filters as input but the quantizer needs the input to be spectral components!!! I didn't see an FFT between the filter bank and the quantizer that |
a**i
发帖数: 419 | 2 不是特别懂。但我理解这是用bandpass filter的响应来代替spectral components。
理论上它们携带的信息是等效的。
32
to be spectral components!!! I didn't see an FFT between the filter bank and
the quantizer that transforms the time-domain samples to frequency domain.
Confused??
time-domain input samples transformed to frequency via the bandpass filters?
bandpass filters so they are transformed to the frequency domain by the MDCT
【在 d*******n 的大作中提到】
: For MP1 and MP2, 假设input frame is 512 samples. after it is fed into 32个
: bandpass PQMF filter， the output is 512 spectral components grouped into 32
: banks or 512 time-domain samples?
: Since the input is time-domain samples, the output of the bandpass filters
: should be also time-domain samples, right? If so, quantizer will take the
: output of the bandpass filters as input but the quantizer needs the input to be spectral components!!! I didn't see an FFT between the filter bank and the quantizer that
|
d*******n
发帖数: 369 | 3 I have a similar and fuzzy feeling as yours but I want to know the detailed
explanation and detailed implementation. I just couldn't find them online
and in books.
这里关键是携带的形式，quantizer 需要的是一个spectrum!
and
.
filters?
MDCT
【在 a**i 的大作中提到】
: 不是特别懂。但我理解这是用bandpass filter的响应来代替spectral components。
: 理论上它们携带的信息是等效的。
:
: 32
: to be spectral components!!! I didn't see an FFT between the filter bank and
: the quantizer that transforms the time-domain samples to frequency domain.
: Confused??
: time-domain input samples transformed to frequency via the bandpass filters?
: bandpass filters so they are transformed to the frequency domain by the MDCT
|
d*******n
发帖数: 369 | 4 I have a similar and fuzzy feeling as yours but I want to know the detailed
explanation and detailed implementation. I just couldn't find them online
and in books.
这里关键是携带的形式，quantizer 需要的是一个spectrum!
这里没人玩Audio coding 的吗？
and
.
filters?
MDCT
【在 a**i 的大作中提到】
: 不是特别懂。但我理解这是用bandpass filter的响应来代替spectral components。
: 理论上它们携带的信息是等效的。
:
: 32
: to be spectral components!!! I didn't see an FFT between the filter bank and
: the quantizer that transforms the time-domain samples to frequency domain.
: Confused??
: time-domain input samples transformed to frequency via the bandpass filters?
: bandpass filters so they are transformed to the frequency domain by the MDCT
|
