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HELP!trying to double SSLIMIT in mpg123ref decoder, mpg123 dist10 ref
robc
post Aug 22 2005, 10:56
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hey guys, need some urgent help.
currently doing a project using the mpg123 dist10 ref code lsf DECODER, and im trying to double the number of samplesPerFrame....

after realising i cant just change "samplesPerFrame", I am concentrating on doubling SSLIMIT from 18 to 36...(as well as various loops with 18, and loops around pcm_sample)

with the theory that i will produce a .dec file that is twice the size and length of the original mp3 that plays at a slower speed but with the same pitch....

at the moment all i am getting is a file double the size ...that plays at half speed and sounds inaudible ...

any ideas would b greatly appreciated smile.gif
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smack
post Aug 23 2005, 09:36
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Please explain what you are trying to accomplish with your modifications of the MP3 decoder.

QUOTE (robc @ Aug 22 2005, 10:56 AM)
with the theory that i will produce a .dec file that is twice the size and length of the original mp3 that plays at a slower speed but with the same pitch....
at the moment all i am getting is a file double the size ...that plays at half speed and sounds inaudible ...

As I understand it, you want to reduce the playback speed while maintaining the original pitch. Is that correct? If so, why don't you use an existing tool like SoX for this purpose?
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robc
post Aug 24 2005, 13:18
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QUOTE (smack @ Aug 23 2005, 02:36 AM)
Please explain what you are trying to accomplish with your modifications of the MP3 decoder.

QUOTE (robc @ Aug 22 2005, 10:56 AM)
with the theory that i will produce a .dec file that is twice the size and length of the original mp3 that plays at a slower speed but with the same pitch....
at the moment all i am getting is a file double the size ...that plays at half speed and sounds inaudible ...

As I understand it, you want to reduce the playback speed while maintaining the original pitch. Is that correct? If so, why don't you use an existing tool like SoX for this purpose?
*



cheers for the reply. yep, im tryin to reduce the speed but keep the same pitch.
im doing this as an MSc project...thus trying to do it within the code

the crux of the project is to try and reduce audio skew during mp3 streaming...so that if packets are arriving too fast...my skew program can tell the decoder to produce a smaller output to compensate or vice versa....

i think ive narrowed it down to the inverse mdct function...but this is a bit complex

This post has been edited by robc: Aug 24 2005, 19:07
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