Re: [MP3 ENCODER] File format of mp3
Why are there mp3 files in which the value of part2_3_length is zero? e.g. http://php.s3.to/bbs/up/img/216.png Isn't the part2_3_length length of main data per 1granule, 1channel? Because the frame contains totally no sound (the frame is digital silence). ___ mp3encoder mailing list [EMAIL PROTECTED] http://minnie.tuhs.org/mailman/listinfo/mp3encoder
Re: [MP3 ENCODER] RE: LAME on DSP
There's some fixed point reference code which could probably be compiled for the TI device. It's called shine... it doesn't have any psycho-acoustic model Yes, there is Shine code available for fixed point. It could be a good start, but please do not consider it as reference code. It is more an example code with some potential bugs... Regards, Gabriel Bouvigne www.mp3-tech.org personal page: http://gabriel.mp3-tech.org ___ mp3encoder mailing list [EMAIL PROTECTED] http://minnie.tuhs.org/mailman/listinfo/mp3encoder
Re: [MP3 ENCODER] for Mac
Is there any effort to make lame available for Macs? for PowerPC ? Just recompile it... I've implemented it for my shareware Amadeus II. Martin ___ mp3encoder mailing list [EMAIL PROTECTED] http://minnie.tuhs.org/mailman/listinfo/mp3encoder
[MP3 ENCODER] Lame DLL
There are two problems I have with the lame encoder DLL:
1. there is no way to set the Noise shaping psycho acoustic algorithms:
corresponding to the comandline arguments of Lame
-q argarg = 0...9. Default -q 5
-q 0: Highest quality, very slow
-q 9: Poor quality, but fast
-h Same as -q 2. Recommended.
-f Same as -q 7. Fast, ok quality
Hence you are stuck with -q 5 (which often is not good enough or not fast
enough:
2. This is a bug (and I hope someone can fix it for me or explain how I can
put a fix into the official lame cvs repository myself.)
If you produce mp3 streaming audio, it is common
to use average bitrate (--abr ) and not have a VBR tag
(since it has to be added to the beginning of the stream
after all of the stream is written. Impossible)
The only place to set the WriteVbrTag is here:
if ( lameConfig.format.LHV1.bEnableVBR )
{
lame_set_VBR( gfp, vbr_default );
lame_set_VBR_q( gfp, lameConfig.format.LHV1.nVBRQuality );
if (lameConfig.format.LHV1.bWriteVBRHeader==TRUE)
{
lame_set_bWriteVbrTag( gfp, 1 );
}
else
{
lame_set_bWriteVbrTag( gfp, 0 );
}
}
else
{
lame_set_VBR( gfp, vbr_off );
}
it requires EnableVBR==TRUE and WriteVBRHeader==FALSE
To get average bitrate you have to set the average bitrate to a positive
value:
// Use ABR?
if (lameConfig.format.LHV1.dwVbrAbr_bps0)
{
// set VBR to ABR
lame_set_VBR( gfp, vbr_abr );
unfortunately next comes:
// Use VBR?
if ( lameConfig.format.LHV1.bEnableVBR )
{
switch ( lameConfig.format.LHV1.nVbrMethod)
{
case VBR_METHOD_NONE:
lame_set_VBR( gfp, vbr_off );
break;
case VBR_METHOD_DEFAULT:
lame_set_VBR( gfp, vbr_default );
break;
. . .
case VBR_METHOD_ABR:
lame_set_VBR( gfp, vbr_abr );
break;
and sice we have enabled VBR and VbrMethod is an undocumented feature (not
described in LameDLLInterface.htm) we are stuck with the default VbrMethod==0
that is VBR_METHOD_DEFAULT and we are back to variable bitrate and not
average bitrate.
Solutions:
1. Make VbrMethod a documented feature.
2. Remove the test for WriteVBRHeader and the call to lame_set_bWriteVbrTag
from its nesting inside the EnableVBR test and make it an independent test.
Best use both solutions 1 and 2.
Who can help ?
Martin Ruckert
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[MP3 ENCODER] Bitrate for archival quality (no perceivable differences fromoriginal)
I'd like to know the lame developer's opinion about the bitrate to chose to have mp3s with no perceivable differences from the original (for 99% of people, 100% is possible only with WAVs). I always chose VBR q=2 or 3, in order to have a medium bitrate of 192-224. I'm asking this to you because you did listening test, while I have only a couple of earphones. Thank you Olaf Marzocchi P.S. What do you think about ogg vorbis? is it useful only for low bitrates or does it produce better results than mp3 even at higher bitrates? (=160)? [EMAIL PROTECTED] for every kind of mail, except spam! :-) ___ mp3encoder mailing list [EMAIL PROTECTED] http://minnie.tuhs.org/mailman/listinfo/mp3encoder
Re: [MP3 ENCODER] Lame DLL
Martin,
1) You can set the quality using the format.LHV1.nQuality parameter
2) To get ABR with You have to set the following parameters (using the
latest CVS code, it already
contains the modifcation you have suggested)
lameConfig.format.LHV1.nVbrMethod = VBR_METHOD_ABR
lameConfig.format.LHV1.bEnableVBR = TRUE;
lameConfig.format.LHV1.bWriteVBRHeader = FALSE;
lameConfig.format.LHV1.dwVbrAbr_bps = (desired value)
I'll change the documentation later tonight and add the nVbrMethod paramter
description
Albert
- Original Message -
From: Martin Ruckert [EMAIL PROTECTED]
To: mp3 encoder list [EMAIL PROTECTED]
Sent: 30 July 2002 ?. 12:25 PM
Subject: [MP3 ENCODER] Lame DLL
There are two problems I have with the lame encoder DLL:
1. there is no way to set the Noise shaping psycho acoustic algorithms:
corresponding to the comandline arguments of Lame
-q argarg = 0...9. Default -q 5
-q 0: Highest quality, very slow
-q 9: Poor quality, but fast
-h Same as -q 2. Recommended.
-f Same as -q 7. Fast, ok quality
Hence you are stuck with -q 5 (which often is not good enough or not
fast
enough:
2. This is a bug (and I hope someone can fix it for me or explain how I
can
put a fix into the official lame cvs repository myself.)
If you produce mp3 streaming audio, it is common
to use average bitrate (--abr ) and not have a VBR tag
(since it has to be added to the beginning of the stream
after all of the stream is written. Impossible)
The only place to set the WriteVbrTag is here:
if ( lameConfig.format.LHV1.bEnableVBR )
{
lame_set_VBR( gfp, vbr_default );
lame_set_VBR_q( gfp, lameConfig.format.LHV1.nVBRQuality );
if (lameConfig.format.LHV1.bWriteVBRHeader==TRUE)
{
lame_set_bWriteVbrTag( gfp, 1 );
}
else
{
lame_set_bWriteVbrTag( gfp, 0 );
}
}
else
{
lame_set_VBR( gfp, vbr_off );
}
it requires EnableVBR==TRUE and WriteVBRHeader==FALSE
To get average bitrate you have to set the average bitrate to a positive
value:
// Use ABR?
if (lameConfig.format.LHV1.dwVbrAbr_bps0)
{
// set VBR to ABR
lame_set_VBR( gfp, vbr_abr );
unfortunately next comes:
// Use VBR?
if ( lameConfig.format.LHV1.bEnableVBR )
{
switch ( lameConfig.format.LHV1.nVbrMethod)
{
case VBR_METHOD_NONE:
lame_set_VBR( gfp, vbr_off );
break;
case VBR_METHOD_DEFAULT:
lame_set_VBR( gfp, vbr_default );
break;
. . .
case VBR_METHOD_ABR:
lame_set_VBR( gfp, vbr_abr );
break;
and sice we have enabled VBR and VbrMethod is an undocumented feature (not
described in LameDLLInterface.htm) we are stuck with the default
VbrMethod==0
that is VBR_METHOD_DEFAULT and we are back to variable bitrate and not
average bitrate.
Solutions:
1. Make VbrMethod a documented feature.
2. Remove the test for WriteVBRHeader and the call to
lame_set_bWriteVbrTag
from its nesting inside the EnableVBR test and make it an independent
test.
Best use both solutions 1 and 2.
Who can help ?
Martin Ruckert
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[MP3 ENCODER] Away until Tuesday
All, I'll be away until Tuesday. What this means is that e-mail posted by non-subscribers of mp3encoder will be delayed, as will new subscriber requests to mp3encoder. I'll process these when I get back. Warren ___ mp3encoder mailing list [EMAIL PROTECTED] http://minnie.tuhs.org/mailman/listinfo/mp3encoder
