Audio compression software

[cooljethro]

Are there any good, free options out there, that can reduce the size of mp3 files significantly, but without a great deal of quality loss?

It would be good to recommend only software that you have tried personally, if applicable.

Thanks!

 

[Outdated]

Are there any good, free options out there, that can reduce the size of mp3 files significantly, but without a great deal of quality loss?

Actually a complex question.

There's no such thing as more compression with no loss of quality.

Reducing the size of MP3s (more compression) reduces the quality of the sound, in some instances this is more acceptable than in others. If your recordings are complex sounds such as a full orchestra playing you'll notice the degradation in the quality of the sound quite dramatically, where as if you're recordings are just voices such as audio books you can compress them quite a bit without them becoming too bad.

I have no experience with audio specific editing software but a lot of video editors also have quite a range of features to deal with the audio. An MP3 is literally the sound track from an MP4.

Especially if you're using Linux, give KD Enlive a go. Just remember to only work on copies of files and not the originals until you work a out a system that's suitable for your needs.

Kdenlive - Free and Open Source Video Editor

 

[Angular Chap]

I use Audacity audio software or ffmpeg from the Linux terminal.

Audacity is free, runs on everything and has plenty of options. You might need to experiment a bit to find the balance of file size vs quality to suit your own personal taste, using presets or going deeper into all the options.

Here’s a nice tutorial on how to do it in Audacity that covers some good stuff:

How to Export Audio with a Lower Bitrate in Audacity (Reduce File Size) - Hollyland

If you want to go the terminal route, the command I use is:

ffmpeg -i name_of_input_file.mp3 -b:a 96k name_of_output_file.mp3

The 96k is the bitrate. Choose a lower one for lower file size. 32k, 64k or 96k are what I use.

 

[Judge]

I also use Audacity 3.4.2 to edit both compressed and uncompressed files into the MP3 format. Though as @Outdated pointed out, reducing the file size inherently translates into lowering the bitrate which in turn lowers sound quality, depending on your own sense of hearing. I like to think I can often tell something recorded at less than 192kbps, though I suspect it really depends on the music itself.

Most of the work I do actually takes sources recorded at lower bitrates (128kbps) where I edit them and ultimately save them at a constant 192kbps. They won't sound as good as something recorded natively in an uncompressed format, but then a lot of music I record is no longer commercially available or on the market only for scalpers' prices.

Ultimately you just have to depend on your own sense of hearing to make such a judgment, apart from using tools like Audacity to make it happen. But expect to degrade sound if smaller file sizes are your main objective.

I never consider file size, but always keep any source archived at a constant 192kbps, sample rate at 44100Hz and a default sample format at 16-bit. Essentially numbers reflecting CDs circa 1990. But if you use a higher rate at 24-bit and can clearly hear the difference, go for it.

One thing for sure, when I'm ripping a CD with an uncompressed .wav or .cdr format, the file size always seems huge compared to the MP3 format I convert them to at 192kbps.

 

[Outdated]

Most of the work I do actually takes sources recorded at lower bitrates (128kbps) where I edit them and ultimately save them at a constant 192kbps. They won't sound as good as something recorded natively in an uncompressed format, but then a lot of music I record is no longer commercially available or on the market only for scalpers' prices.

That's where my experience is the opposite of what @cooljethro wants and what @Angular Chap does - I have very sensitive hearing and I'm a bit fussy about my music, most of it I ripped from CDs myself at 256Kbits/second.

With the size of harddrives people have these days there's little point in trying to reduce file sizes unless you're trying to cram a lot in to a mobile device such as a USB Thumbstick.

I've never attempted to listen to an audio book though, not just audio processing disorder but there's something strange about someone else reading a story to me, they don't read it the same as I would read it myself.

 

[Judge]

That's where my experience is the opposite of what @cooljethro wants and what @Angular Chap does - I have very sensitive hearing and I'm a bit fussy about my music, most of it I ripped from CDs myself at 256Kbits/second.

With the size of harddrives people have these days there's little point in trying to reduce file sizes unless you're trying to cram a lot in to a mobile device such as a USB Thumbstick.

I've never attempted to listen to an audio book though, not just audio processing disorder but there's something strange about someone else reading a story to me, they don't read it the same as I would read it myself.

So much of the equation ultimately depends on one's own sense of hearing. I've tried a number of times saving an MP3 with optimal settings, and it's always the same when I play them back. That I just cannot hear any difference from them compared to my standard 192kbps, 16-bit recordings.

Every once in awhile my OCD tendencies ponder the idea of re-recording much of my music collection in 256kbps, but then I realize how much work it would be that I cannot honestly justify with my hearing. Oh well...

In my own case though I'd rather find the resources to archive music at the highest bitrate I can discern than to make use of more file space.

 

[Outdated]

So much of the equation ultimately depends on one's own sense of hearing. I've tried a number of times saving an MP3 with optimal settings, and it's always the same when I play them back. That I just cannot hear any difference from them compared to my standard 192kbps, 16-bit recordings.

As you mentioned above, what quality the files were originally recorded at limits what you're going to get. You can't "remove" that type of compression, it works by deleting information in exactly the same way as Jpeg compression does. You can make the file bigger again but you can't magically reinstate what is no longer there.

 

[Judge]

As you mentioned above, what quality the files was originally recorded at limits what you're going to get. You can't "remove" that type of compression, it works by deleting information in exactly the same way as Jpeg compression does. You can make the file bigger again but you can't magically reinstate what is no longer there.

Yep. That's the compromise I knowingly make each time given music I cannot find or is stupid expensive by scalpers trying to take advantage of certain genres other than the most popular music that sells so well.

The one good thing I have to say about the earlier era of vinyl records wasn't the records themselves (ick) but the huge selection I could find at the nearby Tower Records.

One dynamic I detest about the advancement of audio technology, is how with each new way of improving sound quality, dynamic range, signal-to-noise ratio, etc.....is how the selection of available commercial music recordings in the later formats become fewer and fewer.

 

[Outdated]

I stopped buying CDs when the last ones I bought didn't have music in CDA format but instead just had MP3s on them, at 196 Kbps.

 

[Judge]

I stopped buying CDs when the last ones I bought didn't have music in CDA format but instead just had MP3s on them, at 196 Kbps.

Yep. It's been years since I last bought one in a native uncompressed format.

Though I will say this. Most of the time I listen to music is in my car, with my Bose nine-speaker 285-watt multiplex audio system. With road and engine noise, my .MP3s need not be optimal recordings. But when playing the same files in my living room on either of my indoor audio systems, then I get a bit picky.

 

[cooljethro]

I just tried to compress an audiobook that was 338mb originally and lowered the sample rate (whilst maintaining the same bit rate as I couldn't go any lower - it was already 64kbps) and changed to mono from stereo, which should have reduced the file size, but it didn't, it was still exactly 338mb after export, even being mono and a having a lesser sample rate. I'm not sure how that is possible, but it is what it is.

So I tried an alternative strategy, I changed the file format to OGG instead of MP3 with the same bit rate and same sample rate and that did the trick - it lowered the file size by about 33%.

With regards to space, I have small-ish SSD for my main drive in my main computer and this thing has gotten full pretty quickly, even without putting much on it, so space saving is definitely a thing, unless I want to use external storage which is slower via USB at least...

 

[Outdated]

With regards to space, I have small-ish SSD for my main drive in my main computer and this thing has gotten full pretty quickly, even without putting much on it, so space saving is definitely a thing, unless I want to use external storage which is slower via USB at least...

Over 300 meg is not a little file, wouldn't take too many of them to fill up a drive. Mine is all music and even one of Jimmy Page's guitar solos is only around 10 megs.

 

[Judge]

One thing to consider is in using a program like Audacity, you can always reduce file sizes by simply eliminating certain tracks that you might be indifferent to. When I first archived all my music I quickly realized that with pop and rock genres, I was only listening to select tracks. I finally concluded that those tracks I never would really listen to didn't have to be there. Giving me that much more space for tracks I listen to a lot.

 

[Outdated]

....by simply eliminating certain tracks .....

That was something I learnt from some musicians back in the 90s, and the true beauty of the CDA format - all the individual tracks are in it, the file hasn't been "flattened" to use a graphics term. These blokes were playing as a trio, little corner pub gigs on Friday and Saturday nights. Electric guitar, base guitar and acoustic guitar, percussion and other instruments came from a laptop plugged into an amp.

They were stripping individual tracks themselves from commercial CDs, it's probably a lot simpler these days but back then your computer had to have 2 midi devices in order to do it. These were musicians, a Yamaha keyboard is a midi device so that got plugged in to a com port in the back of the computer and then everything worked easy peasy.

Can't remember what software they were using back then though but they showed me all the different tracks from a song on the screen and saved only the individual tracks they wanted as an MP4 - not MP3. That was so he could have the lyrics scrolling on the screen just in case he needed it. He also had a portable CD burner he could plug in, quite often different publicans all check out their competition and he picked up a lot of gigs just by publicans chatting to him during breaks and asking what sort of pay they wanted. He'd burn a CD of the next few songs they played and give it to the publican as a demo.

That all seems pretty straightforward these days but this was futuristic thinking back in the 90s.

 

[Judge]

I just tried to compress an audiobook that was 338mb originally and lowered the sample rate (whilst maintaining the same bit rate as I couldn't go any lower - it was already 64kbps) and changed to mono from stereo, which should have reduced the file size, but it didn't, it was still exactly 338mb after export, even being mono and a having a lesser sample rate. I'm not sure how that is possible, but it is what it is.

So I tried an alternative strategy, I changed the file format to OGG instead of MP3 with the same bit rate and same sample rate and that did the trick - it lowered the file size by about 33%.

With regards to space, I have small-ish SSD for my main drive in my main computer and this thing has gotten full pretty quickly, even without putting much on it, so space saving is definitely a thing, unless I want to use external storage which is slower via USB at least...

WTG. At least in recording an audio book I suspect the spoken word is a bit more manageable compared to the complexities of music. Using distinctly lower bitrates, as this article confirms:

"OGG Vorbis sounds better than MP3 at the same bitrate, but MP3 is supported on more devices. If compatibility is your priority, use MP3. If quality at smaller file sizes matters more, use OGG."

Audacity also works with this format as well.

OGG vs MP3: Quality, Compatibility, and Which to Use