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LamedropXPd > Mp3V0 > low kbps?

I was converting ma4 to wav and then to mp3, so I used lamedropXPd to convert wav to mp3. I set it to V0, yet the kbps of the converted mp3's doesn't go over 150kbps.

I am new to doing this kind of thing, but my understanding is that V0 220 - 260. So I am confused.. 




LamedropXPd > Mp3V0 > low kbps?

Reply #1
The first thing to learn about audio encoders is:

trash in -> trash out.  Audio encoders will not magically improve a signal.

The second thing to learn about audio encoders is:

lossy to lossy (spelled transcoding) = lower quality. Encoding a file that was previously encoded with another lossy encoder lowers the quality (some times is not perceptible, others is annoying).



So if you add lesson 1 and lesson 2, you've got that your mp4 (m4a) converted to mp3 has less quality than the mp4 it started from.  Using V0 will not make it any better if what you started with is a 128kbps mp4.


If you had started from an original file (like, from a comercial CD), then, you could still get low bitrates with V0, but then, the reasons are: small complexity (some types of classical music, or similar), and/or being nearly mono.

LamedropXPd > Mp3V0 > low kbps?

Reply #2

Thanks for the reply, defiantly learnt some stuff!

[quote author=[JAZ] link=msg=727777 date=1287599088]
The first thing to learn about audio encoders is:

trash in -> trash out.  Audio encoders will not magically improve a signal.[/quote]

Not to sure I understand this. Certainly I don't expect to get better quality through this conversion, I just wanted to put them into a decent quality mp3.

Quote
The second thing to learn about audio encoders is:

lossy to lossy (spelled transcoding) = lower quality. Encoding a file that was previously encoded with another lossy encoder lowers the quality (some times is not perceptible, others is annoying).


This I didn't realise this. I had assumed(or I think I may have read elsewhere) that lossy to lossy wouldn't damage the quality.

Quote
So if you add lesson 1 and lesson 2, you've got that your mp4 (m4a) converted to mp3 has less quality than the mp4 it started from.  Using V0 will not make it any better if what you started with is a 128kbps mp4.


yep. Though the m4a files I am working from range from 350kps to 500kpbs

Quote
If you had started from an original file (like, from a comercial CD), then, you could still get low bitrates with V0, but then, the reasons are: small complexity (some types of classical music, or similar), and/or being nearly mono.


ah yes these are mono and I guess some are "minimal".

So what would be the best way/utility to convert m4a to mp3?


LamedropXPd > Mp3V0 > low kbps?

Reply #3
Quote
So what would be the best way/utility to convert m4a to mp3?
I think what you're doing is fine.

You might find a utility that converts "directly" from M4A to MP3, but the M4A always has to be decmpressed first...  Either you do it as a separate step, or it happens automatically in the background.  Since WAV is lossless, there is no quality-loss in the extra conversion to WAV.  (Converting to WAV, you usually loose any ID3 tags.  So, if your files are tagged it's nice if you can find a utulity that can do it in one step and keep the tags.)

How does it sound?  V0 should be very good, and LAME is "smart".  It will use a higher bitrate if needed for sound quality (or if a highter bitrate would help sound quality).  If a lower bitrate won't affect sound quality, it will use a lower bitrate which will give you  smaller file.

Quote
So what would be the best way/utility to convert m4a to mp3?
Data is lost every time you compress with lossy compression.  The original compression to M4A was lossy and you're introducing another lossy compression step.  (This does NOT mean that you ALWAYS hear  "audio quality" loss...  But the original audio data is gone and you can't get that exact-original data back.)

LamedropXPd > Mp3V0 > low kbps?

Reply #4
How does it sound?  V0 should be very good, and LAME is "smart".  It will use a higher bitrate if needed for sound quality (or if a highter bitrate would help sound quality).  If a lower bitrate won't affect sound quality, it will use a lower bitrate which will give you  smaller file.


yea it sounds fine to me. I actually played it back in comparison to the m4a and, at least on this system, I couldn't tell much difference if any.

Quote
Quote
So what would be the best way/utility to convert m4a to mp3?
Data is lost every time you compress with lossy compression.  The original compression to M4A was lossy and you're introducing another lossy compression step.  (This does NOT mean that you ALWAYS hear  "audio quality" loss...  But the original audio data is gone and you can't get that exact-original data back.)


I thought M4A was "Apple Lossless Audio"? That's what they are identified as in iTunes. 




LamedropXPd > Mp3V0 > low kbps?

Reply #5
I thought M4A was "Apple Lossless Audio"? That's what they are identified as in iTunes.

.m4a started as Apple's made-up extension for AAC audio. Unfortunately, almost all programs seem to have adopted that unofficial extension. ALAC (Apple Lossless Audio Codec) is also stored in .m4a, which is simply .mp4 with a renamed extension. AAC audio is usually stored in the MP4 container, but Apple decided to use .m4a to differentiate .mp4 files that contain only audio from ones that also have video, for which I believe they made up the extension .m4v.

LamedropXPd > Mp3V0 > low kbps?

Reply #6
So what would be the best way/utility to convert m4a to mp3?


What is your need to convert AAC to MP3? I've found that every player that can play MP3 can also play AAC. If it's a file size issue, my suggestion is just run it through LAME and deal with any artifacts that arise (though you might not notice them anyway).

 

LamedropXPd > Mp3V0 > low kbps?

Reply #7
So what would be the best way/utility to convert m4a to mp3?


What is your need to convert AAC to MP3? I've found that every player that can play MP3 can also play AAC. If it's a file size issue, my suggestion is just run it through LAME and deal with any artifacts that arise (though you might not notice them anyway).


That is untrue.

There are plenty of players that can play WAV or MP3 that can't handle AAC.

EDIT:  I'm talking about hardware standalone players, like DVD players, older MP3/CD players, some car CD/MP3 players, etc.

 
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