[Live-devel] Two questions

Ross Finlayson finlayson at live.com
Fri Feb 20 10:38:06 PST 2004

At 01:17 PM 2/20/04, you wrote:
>I have two questions:
>1. What is the purpose of many table construction in MP3FrameParams's 

The library contains functionality for transcoding MP3 audio from one bit 
rate to another (lower) bitrate.  These tables (which are originally from a 
legacy MP3 decoder implementation) are used to implement this transcoding 

>Is it necessary for streaming mpeg audio?

No, but you should probably just leave that code alone.  Note the use of 
the static variable "doneInit" in the "MP3FrameParam" constructor - so 
those tables are only ever initialized once.

>2. In MultiFramedRTPSink::afterGettingFrame1, there is a numTruncatedBytes 
>parameter.However, which function will set this parameter?

It is set in "FramedSource::afterGetting()", from the "fNumTruncatedBytes" 
member variable.  By default, that variable is set to 0 (in 
"FramedSource::getNextFrame()"), but it can also be set by the source's 
"doGetNextFrame()" virtual member function - if truncation actually occurs.

	Ross Finlayson

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