OGG -> WAV -> MP3 ???

[dbample]

Re: OGG -> WAV -> MP3 ???

Not knowing about the internals, I thought it might be feasible to convert OGG format to MP3 format by converting OGG representation to MP3 representation directly.

Let me comment on this as well. I think a basic problem with trying to do what you describe above is that the mp3, ogg, and other audio compression algorithms work only on an uncompressed file, a wav audio stream. This is not coincidental since the audio stream can be analyzed as a wavelet and in frequency space as it is a direct representation of the actual sound waves.

In order for your idea to work one must develop a cross-conversion (not compression) algorithm that works on an already compressed file (typically compressed by a different compression algorithm) so that the file can be converted to another compression format - all that without the benefit of being able to analyze the sound wave. I don't think these conversion algorithms would be easy to do (or even possible).

[learjeff]

Re: OGG -> WAV -> MP3 ???

Right - 'taint simple.

The only way [converting MP3 to OGG] would add to lossyness is if MP3 was incapible of representing something OGG was.

This argument sounds good but doesn't hold water. They're both nonlinear transformations. Feeding a signal through two transformations doesn't do the same thing as running it through just the worst of them. The results are nearly guaranteed to be worse, regardless of direction (MP3 -> OGG or vice versa).

Given you have MP3 already and want to convert to OGG, it shouldn't matter whether you convert to WAV inbetween. dBPowerAmp either supports it or not (I find that some cross-codings do work and others don't), but by definition they're equivalent to converting to WAV in between.

PS: dbample: the range of 16 bit two's complement integers is -32768..32767. The negative range gets one more value because zero uses up one value in the positive range (sign bit = 0). I've actually programmed a computer that used 1's complement arithmetic, where there were two representations for zero (positive and negative). Two's complement is better!

Cheers
Jeff

[dbample]

Re: OGG -> WAV -> MP3 ???

PS: dbample: the range of 16 bit two's complement integers is -32768..32767.

Thanks, changed in my original post.