MP3 encoder/decoder?

**JSoftware** · 08-12-2010, 11:58 PM

I'm not aware of any newer units, but it looks like those are newer versions of some lame_decode_* functions

But should be easy enough

Code:

type
 lameInt = longint; // Use cint from ctypes in fpc, or smallint on linux
 
 mp3data_struct = packed record
  header_parsed,
  stereo,
  samplerate,
  bitrate,
  mode,
  mode_ext,
  framesize: lameInt;
  
  nsamp: longword;
  
  totalframes,
  framenum: lameInt;
 end;

function hip_decode_init: pointer; cdecl; external 'Lame_enc.dll';
function hip_decode_exit(gfp: pointer): longint; cdecl; external 'Lame_enc.dll';
function hip_decode(gfp: pointer; mp3buf: pointer; len: longint; PcmL, PcmR: pword): longint; cdecl; external 'Lame_enc.dll';
function hip_decode_headers(gfp: pointer; mp3buf: pointer; len: longint; PcmL, PcmR: pword; var mp3data: mp3data_struct): longint; cdecl; external 'Lame_enc.dll';

**chronozphere** · 09-12-2010, 12:21 AM

Thanks.

I'm not very good at porting C(++) yet. I'm afraid to make subtle mistakes that will cost me hours of my precious time to fix. Well, maybe I should just try it someday.

As you may expect: The actual header is way bigger that that sample. About 1200 lines. It might be good to have a pascal version of it. However, the decode functionality of LAME is based on mpg123 code that was released under GPL, so some people may want to go down other paths instead.

Thus far, I think that using mpg123 for decoding and LAME for encoding might be "easiest". I can also attempt a header port and use LAME for both encoding and decoding.

Does anyone know any alternatives? I'm sure I have more options, but I'd like to know more of them.

**JSoftware** · 09-12-2010, 01:24 AM

You could write a decoder yourself...

That might be a too big undertaking. I'm not well aware of any other good decoders

I would write one if it wasn't so hard to get my hands on a real and complete specification. Just for the sake of getting rid of irritating semi-crossplatform dependencies. I got MP1 working, but I haven't even been able to test it since I can't find an encoder for it...