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Lossy Audio Compression => MP3 => MP3 - Tech => Topic started by: Istrebitel on 2012-07-12 16:03:39

Title: Is LAME reenterable?
Post by: Istrebitel on 2012-07-12 16:03:39
Greetings.

I am experimenting with Lame from programming point of view, and having wierd results. I have a question - is LAME reenterable, meaning, does it store anything in its inner variables, and can i encode/decode multiple files at once (if i keep multiple global lame structure instances of course)
Title: Is LAME reenterable?
Post by: lvqcl on 2012-07-12 16:11:15
what functions do you use?
Title: Is LAME reenterable?
Post by: Istrebitel on 2012-07-13 09:54:10
Well, i basically do the same that command line utility does (one that comes with lame) - i use lame_init, i set different parameters, then i use the encode/decode functions in a loop, then close.
Title: Is LAME reenterable?
Post by: Istrebitel on 2012-07-13 11:01:05
I found out, the decoder supplied with LAME was actually non-reentrable, not LAME encoder.

In layer3.c at 1645 it reads:

struct III_sideinfo sideinfo;

So, a global variable is declared, and if multiple decodings are attempted at once, chaos ensues.
Title: Is LAME reenterable?
Post by: lvqcl on 2012-07-13 11:15:09
IIRC lame_decode_* functions aren't thread-safe, but hip_decode_* are.

Quote
In layer3.c at 1645 it reads:

What version do you use?
Title: Is LAME reenterable?
Post by: robert on 2012-07-13 13:06:39
I couldn't find any version with that text at line 1645. Anyway, version 3.99.5 should be OK to use, as I fixed that issue (http://lame.cvs.sourceforge.net/viewvc/lame/lame/mpglib/layer3.c?r1=1.59&r2=1.60&pathrev=MAIN) during the 3.99 development.
Title: Is LAME reenterable?
Post by: Istrebitel on 2012-07-13 15:52:29
lvqcl, thanks, is there any official information about thread-safeness of LAME?

Robert, thanks alot. 

I think what you mean is that my number at which struct III_sideinfo sideinfo; occurs is different, thats because as i said, i was experimenting, so i could've added some code over that line.

I think i'll just apply those changes i am missing since my version and see if they help.