[MP3 ENCODER] "make clean" patch
This is a patch for omitting meaningless process when we do
'make clean' :)
// Though I tried to send this to sulaco.org, csoft.net rejected
// my e-mails. They seem considered me a spammer.
// "ne.jp" (and also "or.jp") exist in their UCE database.
If you are interested in the next stuff, check them at
http://www02.u-page.so-net.ne.jp/ca2/kzmi/lame/patch/
- bitrate histogram update with win32api
- equalizer on lame
Iwasa Kazmi
[EMAIL PROTECTED]
*** lame3.57/Makefile Tue Nov 23 15:34:26 1999
--- MakefileFri Nov 26 20:21:27 1999
***
*** 21,26
--- 21,27
MAKEDEP = -M
BRHIST_SWITCH =
LIBTERMCAP =
+ RM = rm -f
##
***
*** 259,265
ar cr libmp3lame.a $(OBJ)
clean:
! -rm $(OBJ) $(DEP) $(PGM) main.o mp3x.o mp3x libmp3lame.a \
mp3resample.o mp3resample
tags: TAGS
--- 260,266
ar cr libmp3lame.a $(OBJ)
clean:
! -$(RM) $(OBJ) $(DEP) $(PGM) main.o mp3x.o mp3x libmp3lame.a \
mp3resample.o mp3resample
tags: TAGS
***
*** 267,273
--- 268,276
TAGS: ${c_sources}
etags -T ${c_sources}
+ ifneq ($(MAKECMDGOALS),clean)
-include $(DEP)
+ endif
test19: $(PGM)
./lame ../test/castanets.wav
Re: [MP3 ENCODER] Status of noise quantization
> "S" == Segher Boessenkool <[EMAIL PROTECTED]> writes:
>> AFAIK, x and i are energy terms, in which case the first
>> formula gives error in (energy^2); the second gives (error in
>> energy)^2, which is I think a more useful value.
S> x and i are amplitude terms; energy ~ amplitude squared times
S> frequency.
I think so too. x and i are amplitude.
this could be tested by like this.
make enough big "all 1" pcm file and "all 32767" pcm file. like this.
% od ../test1.pcm
000 000400 000400 000400 000400 000400 000400 000400 000400
*
020
% od ../test32k.pcm
000 177577 177577 177577 177577 177577 177577 177577 177577
*
020
and patch lame.c little bit, to print out "xr" value.
% diff -c lame.c lame.c.orig
:
mdct_sub48(mfbuf[0], mfbuf[1], xr, stereo, &l3_side, mode_gr);
+ printf("%e\n", xr[0][0][0]);
:
and make and run the lame with these two files.
% lame ../test1.pcm
:
-4.315976e-05
-4.315976e-05
-4.315976e-05
-4.315976e-05
-4.315976e-05
^C
% lame ../test32k.pcm
:
-1.414216e+00
-1.414216e+00
-1.414216e+00
-1.414216e+00
-1.414216e+00
^C
You can easyly find out
1.414216 / 4.315976e-05 = 32767.003338294744919
And, xr is amplitude and is proportional to the input file amplitude.
not squared(energy).
I think we should use energy difference in db, so the noise formula
should be
sum (10 log (xr^2 - ix^(8/3)))
or
10 log (sum(xr^2 - ix^(8/3)))
and I think the latest quantization method will do the best aproximation
even when we use this noise formula.
---
Takehiro TOMINAGA // may the source be with you!
--
MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )
Re: [MP3 ENCODER] filter options (and several questions)
On Thu, Dec 16, 1999 at 08:06:26PM +0100, Gabriel Bouvigne ([EMAIL PROTECTED]) wrote > ... > It's right that it's not a lot, but I think it's important. As an > example, a standard 10 or 15Hz high pass filter would be nice, as no > one is able to ear such frequencies, so why encoding them? A 10kHz filter, IMHO, would be a bad idea. Even in poor listening conditions with less than adequate equipment this is noticable. It will make most music have a more muddy and boomy sound. 15kHz would be OK for all but very demanding situations. I'd guess that an 18kHz low pass filter would only be noticable with very good/excellent conditions, and an experienced ear. All of these estimates assume a good filter. Setting the coefs. to zero in those regions probably isn't the best way. As mentioned in previous emails, that could lead to some strange distortion. If you use a soundcard/headphone combination for music tests, I'd recommend getting good head phones, and checking out this web page for the performance (especaially DtoA) of various sound cards: http://www.pcavtech.com/soundcards/summary/. A sound card can make a world of difference with its own performance characteristics at various frequencies. An audiophile, John -- MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )
Re: [MP3 ENCODER] filter options (and several questions)
> What is the purpose of this high-pass filtering ? > You said that it would affect only 2 MDCT coeficients, that is > less than a percent of them all, so what gain do you/we expect from it ? In the tuning of the 44.1kHz voice option (I know that this option should be updated now for other bitrates), I added such an high pass filter by zeroing the 2 lower mdct coefficients. In my test cases, it dropped the vbr average bitrate from 121kbps to 120kbps. So it's just a little more than a percent. It's right that it's not a lot, but I think it's important. As an example, a standard 10 or 15Hz high pass filter would be nice, as no one is able to ear such frequencies, so why encoding them? Regards, Gabriel Bouvigne - France [EMAIL PROTECTED] icq: 12138873 MP3' Tech: www.mp3tech.org -- MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )
