WMA ~ MP3 conversion question?

[Kal-El]

Hi all, hope someone can address my question below, thank you in advance for any of your thoughts

Question
-- Why does the mp3 file that i converted using dbpowerAMP take up so much space? For example, i converted an original wma file that was only 3.9MB (@129kbps) into a mp3 file that was 9.6MB (maxed@320kbps). I wasnt expecting the new mp3 file to increase more than double the size of the orignal. I previously used another program that was able to convert wma files into mp3 files @ higher kbps (400 levels), the new files didnt double in size.

Is this normal with dbpowerAMP? What are the best settings to ensure quality and still keep file size reasonable?

[adaywayne]

Re: WMA ~ MP3 conversion question?

Very simple, old chap.....you converted to MP3 at a much higher bitrate. Do the arithmetic....3.9 x 320/129 = 9.69!! Choose a lower bitrate (such as 128) when you convert to MP3 if you want a smaller file.

[ChristinaS]

Re: WMA ~ MP3 conversion question?

Both wma and mp3 files occupy the same amount of space for a given bitrate (give or take a very few bytes).

The file size is directly proportional to the bitrate if CBR is used. So you can actually calculate quite closely what space will be used after conversion, when all other parameters are equal.

Keep in mind that there's absolutely no advantage in converting to higher bitrates, the audio quality will not improve. There is anecdotal (mostly subjective) evidence that wma gives better audio quality than the mp3 at the same bitrate, in particular at lower bit rates. Thus wma@32kbps will be about as good sounding as mp3@64kbps. Does this mean that you should convert a wma to mp3 at double the bitrate? I cannot answer that with any degree of confidence. I personally would convert mp3 to wma at half the bitrate. Not sure if the opposite holds.

[Kal-El]

Re: WMA ~ MP3 conversion question?

I always had the misconception that increasing the bitrate, especially for wma ~ mp3 in general, would increase the quality of the new file. Now i know that this is only commonly true for lower bitrate files.

Thanxs for the insight, much appreicated

[ChristinaS]

Re: WMA ~ MP3 conversion question?

I always had the misconception that increasing the bitrate, especially for wma ~ mp3 in general, would increase the quality of the new file. Now i know that this is only commonly true for lower bitrate files.

Thanxs for the insight, much appreicated

Converting a hi-fi wav original to higher bitrate lossy formats like wma or mp3 will result in better quality for sure than if you convert to lower bitrate. But simply reconverting from an already compressed lossy format to a higher bitrate lossy format will only give you more of the same. A times it may sound a bit better probably because it may be a bit louder.

If I have a poorly sounding compressed file that I'd like to improve, I will first convert it to 16-bit 44.1KHz PCM 2 channel wav and then try to use various tools to enhance the audio as much as I am capable of. This won't restore the orginal wav's quality, but it may make it more acceptable than the lo-fi compressed file, acording to my own taste and judgement. The maybe I will burn it to audio cd or otherwise preserve it in a lossless format.

I recently took a god-awful sounding very lo-fi .ra file (20 Kbps Stereo Music (RealAudio 3.0) 8000 Khz, probably cheap telephone quality), did just that and I managed to have it sounding quite a bit better, I think. Now it sounds just like a poor signal AM band radio station