Conversion question

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LDMartin1959
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Conversion question

Post by LDMartin1959 » Sun Feb 05, 2012 12:52 pm

I'm probably missing the obvious, but I have a number of files I want to convert but are in lower quality bit rates. Since increasing the bit rate would only increase the file size unnecessarily with no gain in audio quality, how do I configure Max to convert the file to M4a at the same bit rate as the source file? It seems the only options are to select preset values.

Any help would be appreciated.

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sbooth
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Re: Conversion question

Post by sbooth » Tue Feb 07, 2012 12:50 pm

What type of M4A files are you going to convert to?

LDMartin1959
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Re: Conversion question

Post by LDMartin1959 » Wed Feb 08, 2012 1:09 am

sbooth wrote:What type of M4A files are you going to convert to?
I'm not sure exactly what you are asking. MPEG-4 Audio AAC is the description. It looks like the only choices are preset bitrates and no option to match the input rate.

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Fuga
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Re: Conversion question

Post by Fuga » Wed Feb 08, 2012 1:49 am

And why do you want to convert? With lossy there will be audible degradation.

LDMartin1959
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Re: Conversion question

Post by LDMartin1959 » Wed Feb 08, 2012 2:56 am

Fuga wrote:And why do you want to convert? With lossy there will be audible degradation.
As I indicated previously, I have files which are in another format and which are not lossless quality. I simply want to convert them to M4V [correction: M4A] at the same bit rate as the original. It is my understanding that this will not negatively impact the sound quality, whereas converting them to a "higher" bit rate will not improve the sound quality but will increase the file size unnecessarily. Perhaps my understanding of the process is not accurate.
Last edited by LDMartin1959 on Wed Feb 08, 2012 4:14 am, edited 1 time in total.

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Fuga
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Re: Conversion question

Post by Fuga » Wed Feb 08, 2012 3:47 am

You will lose stuff. Each format has it's own specific way of taking the data of the whole and deciding what to keep/manipulate as a result. AAC has it's way. Since AAC will be taking from a set of data that is already missing something from the original, and doing so in its own way, there is more loss. The process of a lossy encoding changes data. It's not like the file extension is changing. The data is changing.

LDMartin1959
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Re: Conversion question

Post by LDMartin1959 » Wed Feb 08, 2012 4:15 am

Fuga wrote:You will lose stuff. Each format has it's own specific way of taking the data of the whole and deciding what to keep/manipulate as a result. AAC has it's way. Since AAC will be taking from a set of data that is already missing something from the original, and doing so in its own way, there is more loss. The process of a lossy encoding changes data. It's not like the file extension is changing. The data is changing.
Okay, makes sense. So, will converting to another format at "higher" resolution reduce or eliminate the loss during conversion?

RonaldPR
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Re: Conversion question

Post by RonaldPR » Wed Feb 08, 2012 8:57 am

As far as I know, when converting a lossy format to a different format, only converting to a lossless format will preserve the data (will preserve the data that are the result of decoding). And when you convert that 'lossless' result again to a (any) lossy format, data will again be changed and lost. Once encoded into a lossy format, you are stuck with it if you do not want further quality degradation.

LDMartin1959
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Re: Conversion question

Post by LDMartin1959 » Wed Feb 08, 2012 1:35 pm

RonaldPR wrote:As far as I know, when converting a lossy format to a different format, only converting to a lossless format will preserve the data (will preserve the data that are the result of decoding). And when you convert that 'lossless' result again to a (any) lossy format, data will again be changed and lost. Once encoded into a lossy format, you are stuck with it if you do not want further quality degradation.
Okay. Well... nuts. :cry:

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Fuga
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Re: Conversion question

Post by Fuga » Wed Feb 08, 2012 1:45 pm

Out of curiosity: What is the file format you're wanting to convert from?

And why AAC?

LDMartin1959
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Re: Conversion question

Post by LDMartin1959 » Wed Feb 08, 2012 2:16 pm

Fuga wrote:Out of curiosity: What is the file format you're wanting to convert from?

And why AAC?
AAC, because that is the native format for iTunes. And the conversions are coming from various forms of MP3 and WMA, mostly. I don't have a high-end stereo (wish that I did, but I'm just po' folk) and mostly I listen on my iPod and the add-on speakers for my desktop. While I am generally inclined toward over doing things and high end audio quality on my audio files would be my first choice in an ideal situation, I don't have that so, I am trying to achieve what is (to my mind) the best compromise of efficient use of limited hard drive space, and the best audio quality I can within the capabilities of my equipment. And my ear, which isn't what it used to be.

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Fuga
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Re: Conversion question

Post by Fuga » Wed Feb 08, 2012 3:10 pm

I doubt you'd tell the difference between AAC and MP3 in most cases. File size is different at the same bitrate but not all that much. As for the WMA, yeah the choice is lossless or nothing. I know you're thinking of size but depending on how much WMA data you're talking about converting those to ALAC might not be that big a thing. Similarly, I'd go ahead and test WMA to AAC. Your ears might not tell, or at least be accepting.

For iPod, another option is to use Rockbox on your iPod. It'll handle the WMAs.

For your desktop there are alternatives to iTunes. If you're happy with iTunes then you aren't tempted by more "audiophile" players like Audirvana, Fidelia, or this site's Decibel. An alternative to iTunes level play is Swinsian. It plays all sorts of files, including WMAs. It also has Airplay support. Whenever I find a way to control if from my phone as I can iTunes, I will be dumping iTunes.

LDMartin1959
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Re: Conversion question

Post by LDMartin1959 » Thu Feb 09, 2012 1:04 am

Fuga wrote:I doubt you'd tell the difference between AAC and MP3 in most cases. File size is different at the same bitrate but not all that much. As for the WMA, yeah the choice is lossless or nothing. I know you're thinking of size but depending on how much WMA data you're talking about converting those to ALAC might not be that big a thing. Similarly, I'd go ahead and test WMA to AAC. Your ears might not tell, or at least be accepting.

For iPod, another option is to use Rockbox on your iPod. It'll handle the WMAs.

For your desktop there are alternatives to iTunes. If you're happy with iTunes then you aren't tempted by more "audiophile" players like Audirvana, Fidelia, or this site's Decibel. An alternative to iTunes level play is Swinsian. It plays all sorts of files, including WMAs. It also has Airplay support. Whenever I find a way to control if from my phone as I can iTunes, I will be dumping iTunes.
Fuga, thanks for the info. I'm not sure I am likely to look at iTunes alternative but I may at least take a look at them.

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