Converting mp3 to wav for editing purposes

[Kathy Smith]

Hi,

Unfortunately I got mp3 files at 44.1kHz sample rate and 96k bit rate. I want to do some editing on them, little noise removal, some EQ. Would it make any difference if I converted them to wav first so there is no further degradation when I do work on them? I do know that I'm not making a better quality file by converting it wav. That's not my intend. I'm just hoping that whatever I get in mp3 doesn't keep degrading when I edit the file. I'm not sure if there is any quality loss when converting from mp3 to wav. I'm hoping that once I do work on it in wav format I'm only going to degrade it further when I save it to mp3 again. Is this true? Or is this a waste of time?

[Don Palomaki]

In general every cycle of recompression to a lossy file format results in losses, how significant the losses are will depend on the compression processes and sample rates/depths used. Even working on digital files in a uncompressed format will result in some cumulative losses due to truncation/rounding errors in the A/D process

To minimize losses do all editing/sweetening working with a lossless format files with a bit depth that is hopefully greater than you final distribution format. Example, if you input files are 16-bit, I would use 24-bit intermediate files for all editing, than convert to the distribution format as the very last step.

[Keith Rollinson]

If your editing happens all in one app, and just saving one time again to an .mp3, then mp3->mp3 is best. If you intend to use different apps for signal processing, encountering multiple saves, then an intermediate .wav is a good idea.

[Rick Reineke]

Originally Posted by Kathy Smith

I'm not sure if there is any quality loss when converting from mp3 to wav.?

There should not be any further quality loss transcoding an MP3 to PCM (or 'Saving as in the PCM format), typically WAVE <.wav> .It will not increase the quality though, though many folks mistakenly think it will. The analogy I use to explain it is, "putting one gallon of milk in a 5 gallon container... but it's is still a gallon".
Lossy file types (MP3, AAC, AC-3, ect.) should avoided, except for encoding the final end-user file.

OTOH, some NLEs and DAWs (like Vegas Pro), automatically build floating point 32 bit PCM proxy files when the project's timeline is created, so transcoding is no really necessary, the original file is never overwritten.
So it depends on one's software. When in doubt, transcode lossy audio files to a PCM format.

[Andrew Smith]

The downside of the audio compression already there from the mp3 files is that it's going to be like working with the audio equivalent of mud when it comes to fixing issues.

Tell the client you will do your best, but all bets are off if they supply compressed audio to begin with.

Andrew

[Kathy Smith]

Originally Posted by Rick Reineke

There should not be any further quality loss transcoding an MP3 to PCM (or 'Saving as in the PCM format), typically WAVE <.wav> .It will not increase the quality though, though many folks mistakenly think it will. The analogy I use to explain it is, "putting one gallon of milk in a 5 gallon container... but it's is still a gallon".
Lossy file types (MP3, AAC, AC-3, ect.) should avoided, except for encoding the final end-user file.

OTOH, some NLEs and DAWs (like Vegas Pro), automatically build floating point 32 bit PCM proxy files when the project's timeline is created, so transcoding is no really necessary, the original file is never overwritten.
So it depends on one's software. When in doubt, transcode lossy audio files to a PCM format.

Thanks. Yes, I understand, as I stated in my original post that there is no increase in quality by converting from mp3 to wav. If there is no data, there is no data, you can't create something from nothing.

[Kathy Smith]

Originally Posted by Andrew Smith

The downside of the audio compression already there from the mp3 files is that it's going to be like working with the audio equivalent of mud when it comes to fixing issues.

Tell the client you will do your best, but all bets are off if they supply compressed audio to begin with.

Andrew

Yes, I'm aware of that and so is the client. Thanks

[Kathy Smith]

Originally Posted by Don Palomaki

In general every cycle of recompression to a lossy file format results in losses, how significant the losses are will depend on the compression processes and sample rates/depths used. Even working on digital files in a uncompressed format will result in some cumulative losses due to truncation/rounding errors in the A/D process

To minimize losses do all editing/sweetening working with a lossless format files with a bit depth that is hopefully greater than you final distribution format. Example, if you input files are 16-bit, I would use 24-bit intermediate files for all editing, than convert to the distribution format as the very last step.

Yes, I'm aware of all of this except that I have no choice but to work with mp3 at the moment, hence my question.

[Kathy Smith]

Originally Posted by Keith Rollinson

If your editing happens all in one app, and just saving one time again to an .mp3, then mp3->mp3 is best. If you intend to use different apps for signal processing, encountering multiple saves, then an intermediate .wav is a good idea.

This makes sense. Thank you!

[Patrick Tracy]

If it's being opened in an audio editor, it's probably being decompressed anyway. Converting as a separate step is redundant. Deliver a WAV file and tell the client not to compress it unless absolutely necessary. Create the project at the sample rate at which you intend to deliver the WAV. It might be good to find out what the intended use is so you can deliver the WAV with the correct bit depth and sample rate.

[Kathy Smith]

Originally Posted by Patrick Tracy

If it's being opened in an audio editor, it's probably being decompressed anyway. Converting as a separate step is redundant. Deliver a WAV file and tell the client not to compress it unless absolutely necessary. Create the project at the sample rate at which you intend to deliver the WAV. It might be good to find out what the intended use is so you can deliver the WAV with the correct bit depth and sample rate.

Intended use is podcast, so they need mp3.

[Patrick Tracy]

Originally Posted by Kathy Smith

Intended use is podcast, so they need mp3.

Then find out the exact parameters of the MP3 in order to prevent the need for more conversion, or deliver WAV and let them convert to the right MP3 themselves. Be sure they understand that unsatisfactory audio quality is most likely the result of their decision to provide a low quality original file.

[Christopher Young]

Originally Posted by Kathy Smith

Hi,

Unfortunately I got mp3 files at 44.1kHz sample rate and 96k bit rate. I want to do some editing on them, little noise removal, some EQ. Would it make any difference if I converted them to wav first so there is no further degradation when I do work on them? I do know that I'm not making a better quality file by converting it wav. That's not my intend. I'm just hoping that whatever I get in mp3 doesn't keep degrading when I edit the file. I'm not sure if there is any quality loss when converting from mp3 to wav. I'm hoping that once I do work on it in wav format I'm only going to degrade it further when I save it to mp3 again. Is this true? Or is this a waste of time?

For simple quick conversion just select "Audio Converter" then add all your files in this online audio app and then download the converted files. You can select the encoder you want plus set sample and bit rates to your choice,

This app also can do many other things as you will see. Bonus? It's all free. :)

https://vocalremover.org/converter

Chris Young

[Paul R Johnson]

Good mp3 files are not always terrible. You need to assess what you have, and importantly, what you will then fo yo them again. Every conversion to a compressed file destroys more, so if your file ends up as .wav, and stays as .wav that’s best, but if it’s going to be compressed again, then a plan is needed to retain as much as you can.

[Kathy Smith]

Originally Posted by Paul R Johnson

Good mp3 files are not always terrible. You need to assess what you have, and importantly, what you will then fo yo them again. Every conversion to a compressed file destroys more, so if your file ends up as .wav, and stays as .wav that’s best, but if it’s going to be compressed again, then a plan is needed to retain as much as you can.

Yeah, that's what I'm asking, how to convert with a minimal loss. Do you have an answer?