Coverting .wav --> .mp3

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DamienD
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Joined: Sun Nov 13, 2005 2:41 am

Coverting .wav --> .mp3

Post by DamienD »

Hello all,

Was thinking about converting my .wav files for various games that ScummVM supports to .mp3 so that I save HDD space.

Firstly, do people think this is a good idea and secondly what's the best software to do this in terms of keeping quality (obviously everyone will have their own preferences to this but I'd like to hear some different opinions)? :?:

Edit:

Please ignore my question, thoroughly went through the readme.txt and found that using LAME is suggested :D
DamienD
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Post by DamienD »

Hi,

I manged to convert all the .wav files to .mp3 files using LAME successfully. Works well :wink:

I also tried converting all the .wav files to .ogg files using OGGENC. These files are even smaller in size...

I do have one question though, I couldn't tell the difference in audio quality by listening to the .wav, the .mp3 or the .ogg files. Is there any difference in quality :?:
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sev
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Post by sev »

Yes, they use somewhat different psychoacoustics models. Generally OGG Vorbis format is considered to be more superior, i.e. it gives better sound quality with smaller files. MP3 is more widespread, though, especially in hardware.


Eugene
DamienD
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Post by DamienD »

Thank you for the info. This is great news as the .ogg files are smaller...

I'll keep these and disguard the .mp3 files.

Might even convert all the rest of .mp3 files that I have for all the other ScummVM supported games :wink:
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eriktorbjorn
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Post by eriktorbjorn »

DamienD wrote:Might even convert all the rest of .mp3 files that I have for all the other ScummVM supported games :wink:
Converting an MP3 file to an Ogg file is probably not a good idea, if that's really what you meant, since both MP3 and Ogg Vorbis use "lossy" compression. That means that what you get when you decode the file isn't quite identical to what you encoded, but hopefully close enough that you won't be able to tell the difference.

So if you encode sound that has already been encoded once, no matter how well the second encoding preserves the data, it cannot recreate that which was lost in the first encoding.

Perhaps a more easyly understood example of lossy compression is JPEG. These images are usually a lot smaller than the corresponding GIF or PNG image, because JPEG is lossy while GIF and PNG are lossless. Most programs that can create JPEG images have a quality setting. Decreasing the quality will create smaller images, but the result will become more noticeably different from the original. Particularly around sharp edges.
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JamesWoodcock
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Post by JamesWoodcock »

eriktorbjorn is correct.

It is a bad idea to compress an already compressed format, as any loss in quality that results from compression is amplified when compressing again.

Always compress from the source.

OGG is the format I use as it is small and superior to that of MP3.
DamienD
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Post by DamienD »

Thank you for your reply guys. Totally understand this concept.

I did actually miss typed, I meant to say .wav --> .ogg :oops:
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