.m4a vs .mp3

[alexis]

Hi,

I came across the .m4a file type for the first time recently, it is the format my Android "Voice Recorder" app uses.

I read on the link below that .m4a files are higher quality than .mp3 files but take up less space, so I thought maybe it was a no brainer - that I should convert to the former when I didn't need to convert to .wav.

But reading further, the linked-to article also said .m4a file can only be played on Apple devices (which I know isn't true because I played one on my W10 computer), so I'm a little unsure how reliable it is.

Amy thoughts on .m4a files, esp in relation to quality vs. .mp3 (or flac), would be much appreciated!

Thank you

https://allsoundlab.net/mp3-vs-m4a/

(Mods: please move to more appropriate location as you see fit. I couldn't tell if the PC forum was better than this Lounge, since the linked to article said mp4 was just an Apple construct, but since I used it on PC and Android, I just couldn't tell ! Thanks. )

[zenguitar]

Moved to the mixing/mastering/production forum as it's a question about a delivery format.



Andy

[Hugh Robjohns]

The .m4a extension denotes the audio container from the mp4 format and normally contains either the loss-less ALAC format (Apple Lossless Audio Codec) or the lossy AAC (Advanced Audio Codec) — both unencrypted.

ALAC is apple's equivalent of FLAC and, like that alternative, reduces the original linear file to about half the size.

AAC is a much more advanced and efficient lossy codec than .mp3, so manages similar sound quality at smaller file sizes (or better quality for similar file sizes).

Years back, AAC and ALAC weren't widely supported outside Fruit-land, but now they both are.

I use ALAC in the .m4a format for my music library because it occupies half the space of ripped .wav files, and it has all the same metadata features as .mp3 — embedded artwork, composer /artist /performer /date /genre /etc.

Personally, I wouldn't convert .mp3 files to .m4a. Concatenated lossy formats can only degrade quality and the small file size gain would be pointless given the sound quality reduction.

But converting .wavs into ALAC is loss-less and convenient, and AAC is very good when file size is an issue for an end-listener.

And both formats are supported very well now on all platforms and streamers.

[adrian_k]

That link has a whiff of being written by AI as click bait to me. Either way it is wrong, m4a files (Apple lossless) can be played on various platforms since an open source decoder was developed years ago. VLC can certainly play them on my PC.

It’s true that m4a is claimed to be lossless. I’m not sure if the files are smaller than mp3, I guess that would depend on the mp3 bitrate.

Edit: ninja’d!

[alexis]

Thank you Hugh and adrian_k (and zenguitar!)

[James Perrett]

It’s true that m4a is claimed to be lossless. I’m not sure if the files are smaller than mp3, I guess that would depend on the mp3 bitrate.

As Hugh says, m4a is just a container that can contain either lossy or lossless files. You need some way of analysing the contents to tell whether the file is lossless or not (although you could probably get a good idea from the file size).

[BWC]

You need some way of analysing the contents to tell whether the file is lossless or not...

Something like...
https://mediaarea.net/en/MediaInfo

[adrian_k]

It’s true that m4a is claimed to be lossless. I’m not sure if the files are smaller than mp3, I guess that would depend on the mp3 bitrate.

As Hugh says, m4a is just a container that can contain either lossy or lossless files. You need some way of analysing the contents to tell whether the file is lossless or not (although you could probably get a good idea from the file size).

Ah thank you, I hadn’t appreciated that m4a files could contain AAC data.