MP3 Conversion clarification/explanation

[Musicman]

Hello

Is there anyone out there who can explain/clarify as follows (in simple words) :

1.- What's the difference (benefits) compressing or converting using VARIABLE or CONSTANT MODE IN MP3's??
2.- What'S the most common or appropriate  bitrate to use ?
3.- How the volume gain (Db plays around the MP3)

Regards.

 

[Neilyboy]

1. Variable bit-rate is in my opinion best to use. Think of giving more where needed in this case. Say you are recording yourself drumming. If you hit the drum once and stop then wait for silence then hit the drum again wait for silence and repeat. What VB (variable bit-rate) does for you is gives you more compression over the silence and gives more data where it is needed. Think of it in video compression as well. Fast moving scenes are going to need more data than slow almost still frames. So the main difference is VB basically takes an average bit-rate say 192k and gives (just for example) 220k to the drum hit (or fast motion in a video) and then 32k or so for the silence (or somewhat still frames in video).
Constant bit-rate just takes a given bit-rate 192k and gives every bit of data 192k throughout.

2. I would say use a variable bit-rate of 192k with decent settings and you should be good to go. I think that is what 'scene' releases are anymore as well.

3. I dont think you should have to mess with the gain of anything if you are ripping the discs yourself. Gain is just upping the levels of everything.

Neil

[Musicman]

Thanks Neil.
Very clear.
These MP3 settings were driving me crazy.

Have a good day.
 

[Space Fractal]

Personal I use 192KBit "flatrate" on most of my ripped songs. I do use other bitrate on the songs as well, but most of them is just 192kbit.

If you dosen't like lossy format of MP3, you should go with FLAC format instead. FLAC work pretty much like ZIP, but have much higher compression than ZIP and save typical about 50% of the original wav file.

[pmc]

As long as I am going MP3 (iPod or whatever), I always use VBRs. I find that it gives me the best sound quality/file size balance. There's no compelling reason to make CBRs unless you have old equipment that chokes on VBRs. VBRs are generally smaller but better sounding.

I'd recommend you use EAC (Exact Audio Copy which is the best and it's free) to rip to WAV and then archive those files as FLAC or SHN (lossless compression). That's your reference copy and it's as perfect as possible. Then use LAME to generate MP3s from the WAVs. I use "--preset standard" which is the same as -V2 (about 190kbps).

For certain types of music you can always increase to V1, or decrease to V3 if the music demands it. Regardless, you can always toss the MP3 files and go back to your reference WAVs to re-encode with the next flavor of the day.

Here's a good page on the topic if you want to read more.

I'd probably switch to Ogg Vorbis, but it won't work on some of my hardware.

-pmc

[richms]

There is still quite a few hardware players that cant seek on vbr files. Technically they are not seeking on the CBR ones, just jumping to an approximate location in the file - with vbr that doesnt work so the onscreen counter is wrong.

Also some software cant longer accurately seek - the only way to do it is to read thru the whole file. When you have a mix cd ripped with a cuesheet and a single mp3 file this is really noticeable since it has to pull the whole file from disk to seek to the tracks at the end.

flac has indexes in it which let it seek accuratly from a location closer to where you want to play from so is much better for long rips IMO.

[Musicman]

Thank you all.
I did receive more info than expected.
 

Great Forum.