PDA

View Full Version : ---alt-preset?


glenn
23rd December 2001, 13:26
I did a test with the new --alt-preset switch of LAME, after all the bragging around of how good it was. The problem, though, is that the resulting files are *much* bigger than they used to, leaving less room for video.

I did a test rip of Broken Arrow (region 2), and encoded the audio with both '--alt-preset standard' and my normal settings, and this is what I found:

--alt-preset file was 141mb
old settings file was 104mb...

For the record, my 'old' settings are:
-m j -v --vbr-old -V 4 -b 80 -B 256

This _is_ a serious issue with 1cd rips, especially if they're long - the bitrate has to be very low in these cases.
Any thoughts?

MaTTeR
23rd December 2001, 15:55
In the 3.90 version of LAME I believe --r3mix has been tuned even more than in the alpha versions. You could try that.

I've seen in the r3mix forums several people using this line for an average bitrate of 128k-
--abr 134 -h --nspsytune --athtype 2 --ns-bass -8 --scale 0.93

I'd suggest you try out something like-
--alt-preset 128 or even --alt-preset 140
This would give you an ABR file instead of a VBR.

If you do a listening test with your old VBR settings and compare it to --alt-preset standard . I think you'll agree that the --alt-preset is much better quality but at the price of bits. As I understand it, the --alt-presets are very dependant on the source material. I'm doing some testing of different settings also, I'll post my finding. Please do the same :)

Psyche
24th December 2001, 00:06
@glenn:
Take a look at the mp3 forum in www.hydrogenaudio.org (http://www.hydrogenaudio.org), and you'll see that the new alt-preset are tuned to a level that is impossible to reproduce its behaviour with discrete switches.
Also everybody agrees that you should use ABR for low bitrates, 'cos in 3.90 VBR are not tuned for LB. What is more, you should use something like --alt-preset 112 and not setting switches manually, 'cos alt-presets enable some bitrate corrections needed to achieve the exact bitrate you aim to.
Of course this is a matter of taste (but hey, the masters rule... :D ).

glenn
24th December 2001, 14:46
OK, so ABR is a better solution than VBR for 3.90+, and enables you to use the better --alt-preset settings and still get files that are +/- 100mb?

I'll experiment a little and see what I find, then. I'm doing "Evolution" tonight, so that's a good source for experimenting I guess. I complete "Broken Arrow" with the old settings.

Snike42
26th December 2001, 04:40
For the record, my 'old' settings are:
-m j -v --vbr-old -V 4 -b 80 -B 256



The reason why your files are getting bigger with the alt-presets is that your old settings have a much lower quality setting (-V4). While the alt-preset standard uses -V2 as quality setting.

The new alt-presets are for high quality audio (cd-quality) and can be compared with the (now obselete) --r3mix preset. If you really want to use VBR then there's no reason to stop using your old settings.

I always use ABR and did some testing with --alt preset 128. This gives very predictable file size and the quality is impressive.

Snike

LotionBoy
26th December 2001, 06:40
I just tested out the new alr preset, and the quality is better than anything I've found with switches, in terms of quality in low-bits. definetely the way to go.

LotionBoy

glenn
26th December 2001, 14:20
I did a new test with '--alt-preset 140', and filesize is comparable - and more importantly, appears to sound better - but don't trust my ears, my hearing's not what it used to be =)

Too much loud rock'n'roll for 15 years will do that to you... ;)

tangent
26th December 2001, 22:09
Originally posted by Snike42


The reason why your files are getting bigger with the alt-presets is that your old settings have a much lower quality setting (-V4). While the alt-preset standard uses -V2 as quality setting.

The new alt-presets are for high quality audio (cd-quality) and can be compared with the (now obselete) --r3mix preset. If you really want to use VBR then there's no reason to stop using your old settings.

I always use ABR and did some testing with --alt preset 128. This gives very predictable file size and the quality is impressive.

Snike

--alt-preset standard actually uses -V4 (it was the older --dm-preset standard which used -V2).

Other methods (noise measuring, short block handling, and others) more than makes up the difference in -V settings (which mostly affects only the ath curve) more efficiently.

pacohaas
27th December 2001, 01:28
Originally posted by tangent
--alt-preset standard actually uses -V4 (it was the older --dm-preset standard which used -V2).This cannot be true because I just backed up some CD's using --alt-preset standard and --alt-preset standard -V4 and the -V4 ones turned up 40-60kbps less than the --alt-preset standard ones.