Announcement

**philippe_44** · 2021-02-02, 07:45

Which file format to use: mp4 (apple lossless) or flac?

Originally posted by chincheta0815

Hey there,

after a long time in the mid age of audio file formats I decided to change the used file format in my LMS from mp3 to a lossless file format.

I am thinking about using one of the two alternatives: m4a (apple lossless) or flac.
Only restriction: The features in respect to LMS and its clients should be the same as with mp3.
As I am using a Mac and iTunes, m4a (apple lossless) would be prefereable in case of no or very few differences...

There is plenty of information about those formats concerning LMS and its clients on the internet, but I did not figure out the latest state-of-the-art in that topics concerning LMS 8.2.

Can anyone help me and explain which would be the best fileformat out of those two?
Are there still any differences or do they work both the same as mp3 on all components?

Thanks in advance.

My 2 cents: use Flac, no hesitation.

MP4 format is a real pain to handle and there is always something wrong with it. Reading mp4 documentation and writing or using a parser makes me nauseous.

Flac is simple, straightforward, takes 10 mins to understand the documentation. Flac is streamable. Flac can easily be encapsulated in Ogg as well.

I’m talking about mp4 in general, as a container, your use case would be using alac inside. I do not think alac gives you better compression or lower cpu usage or lower memory requirement, which does not matter these days anyways.

Everybody supports flac, not alac. I’ve implemented both of them on multiple platforms, including esp32 embedded system and I will always go for flac. On my bridges, I’ve chosen flac as a re-encoder option again because all platforms support it.

Now, you may have extreme metadata expectations that might be better served by mp4, that I would not know.

**ian_heys** · 2021-02-02, 08:03

Originally posted by philippe_44

My 2 cents: use Flac, no hesitation.

MP4 format is a real pain to handle and there is always something wrong with it. Reading mp4 documentation and writing or using a parser makes me nauseous.

Flac is simple, straightforward, takes 10 mins to understand the documentation. Flac is streamable. Flac can easily be encapsulated in Ogg as well.

I’m talking about mp4 in general, as a container, your use case would be using alac inside. I do not think alac gives you better compression or lower cpu usage or lower memory requirement, which does not matter these days anyways.

Everybody supports Flac, not alac. I’ve implemented both of them on multiple platforms, including esp32 embedded system and I will always go for alac. On my bridges, I’ve chosen alac as a re-encoder option again because all platforms support it.

Now, you may have extreme metadata expectations that might be better served by mp4, that I would not know.

I don't follow the first and last paragraphs. If you would always use flac, why then chose alac?

**philippe_44** · 2021-02-02, 08:06

Which file format to use: mp4 (apple lossless) or flac?

Originally posted by ian_heys

I don't follow the first and last paragraphs. If you would always use flac, why then chose alac?

Typo on my bridge comment. I meant Flac, not alac. Basically my recommendation is flac.

Last paragraph I would think that mp4 might have better metadata options but again I hate so much the format’s description that it makes me sick when I read it

**chincheta0815** · 2021-02-02, 08:24

Okay so flac is better due to being better supported by more hardware/players.
ALAC is not supported by all hardware/players, esp. Squeezebox Receiver which I am using?

The metadata I want to use is just the id3tag-info that comes with mp3tags.
So I just think to "copy" the info/tags.
Or am I wrong?

BTW: Is there any recent list/matrix showing those supported audio file systems?

**slartibartfast** · 2021-02-02, 08:43

Originally posted by chincheta0815

Okay so flac is better due to being better supported by more hardware/players.
ALAC is not supported by all hardware/players, esp. Squeezebox Receiver which I am using?

The metadata I want to use is just the id3tag-info that comes with mp3tags.
So I just think to "copy" the info/tags.
Or am I wrong?

BTW: Is there any recent list/matrix showing those supported audio file systems?

Whatever you choose don't use iTunes to rip your CDs. It doesn't verify the rips so you can have errors.

Sent from my Pixel 3a using Tapatalk

**rkrug** · 2021-02-02, 08:46

Which file format to use: mp4 (applelossless) or flac?

I am an Apple Music user, and imported all my Music into iTunes / Apple Music. Therefore I had to transcode from Flac (my main format) to ALAC (Apple Lossless).

This is not satisfactory at all. But I am still using Flac. Why? Quality wise no difference, but: Flac has a build in checksum, which CAN be used to check if the track has been corrupted (bit-rot). There is nothing in ALAC to do this.

Did I ever check my files? No.

So I would say - for all practical purposes, it does not matter as a user of LMS. LMS does transcoding when needed in a transparent way. And unless you have many players, I would not assume this to be too taxing for even a Pi 3.

There are some players which can play LAAC natively, and some canâ€™t, but I do not know which.

Cheers,

Rainer

> On 2 Feb 2021, at 09:24, chincheta0815 <chincheta0815.9wfptb (AT) no-mx (DOT) forums.slimdevices.com> wrote:
>
>
> Okay so flac is better due to being better supported by more
> hardware/players.
> ALAC is not supported by all hardware/players, esp. Squeezebox Receiver
> which I am using?
>
> The metadata I want to use is just the id3tag-info that comes with
> mp3tags.
> So I just think to "copy" the info/tags.
> Or am I wrong?
>
> BTW: Is there any recent list/matrix showing those supported audio file
> systems?
>
>
>
> LMS-7.9 (AT) solaris (DOT) 2x Radio, 2x Duet, 1x Chromecast v1, ShairTunes, 1x
> Philips Hue System
> ------------------------------------------------------------------------
> chincheta0815's Profile: http://forums.slimdevices.com/member.php?userid=42904
> View this thread: http://forums.slimdevices.com/showthread.php?t=113836
>
>

**rkrug** · 2021-02-02, 08:47

Which file format to use: mp4 (applelossless) or flac?

> On 2 Feb 2021, at 09:43, slartibartfast <slartibartfast.9wfqnb (AT) no-mx (DOT) forums.slimdevices.com> wrote:
>
>
> chincheta0815 wrote:
>> Okay so flac is better due to being better supported by more
>> hardware/players.
>> ALAC is not supported by all hardware/players, esp. Squeezebox Receiver
>> which I am using?
>>
>> The metadata I want to use is just the id3tag-info that comes with
>> mp3tags.
>> So I just think to "copy" the info/tags.
>> Or am I wrong?
>>
>> BTW: Is there any recent list/matrix showing those supported audio file
>> systems?Whatever you choose don't use iTunes to rip your CDs. It doesn't verify
> the rips so you can have errors.

Agreed.

XLD is a brilliant tool for a Mac user to transcode and rip CDs - and it checks them vie the accurip database.

>
> Sent from my Pixel 3a using Tapatalk
>
>
>
>
> ------------------------------------------------------------------------
> slartibartfast's Profile: http://forums.slimdevices.com/member.php?userid=35609
> View this thread: http://forums.slimdevices.com/showthread.php?t=113836
>
>

**chincheta0815** · 2021-02-02, 08:55

So I would have to check if my Squeezebox Receiver supports ALAC.
If I transcode or not does not matter for me so far.
Transcoding does not support all features as far as I know e.g. search in the track. But that needs to be confirmed.

My idea for a workflow is:
1. Import the music from the original file format (e.g. rerip from CD or download from iTunes or Amazon),
2. Copy over the tags and cover images from the old, existing mp3 files via a (batch) tool.

Does that sound reasonable?
How does flac/alac support cover embedded into the files? Is that possible?

**mrw** · 2021-02-02, 08:56

Originally posted by chincheta0815

I am thinking about using one of the two alternatives: m4a (apple lossless) or flac.
Only restriction: The features in respect to LMS and its clients should be the same as with mp3.
As I am using a Mac and iTunes, m4a (apple lossless) would be prefereable in case of no or very few differences...

I use a Mac. It is very convenient to have iTunes 'rip' the CDs into apple lossless (m4a), and I use iTunes to edit any tags/artwork. The folder for the music library is well enough sorted. I periodically sync the music library (on the Mac) onto a network share drive, for use by LMS which runs on a different box. So my music library is backed up, too.

I'm not aware of having had any difficulties with LMS. Perhaps I am not adventurous enough. It has always just worked.

**bpa** · 2021-02-02, 10:18

Originally posted by chincheta0815

BTW: Is there any recent list/matrix showing those supported audio file systems?

As stated earlier - LMS using transcoding means most (if not all current) audio formats are playable so whether a player can play a format natively is in practice irrelevant.

So rather than a matrix of what is possible - I think the list of what is NOT possible would be relevant - I think that list is very small and mainly old formats. The only one I can think off at the moment is RealAudio. There are other old codecs or niche (e.g. MIDI) which are/were supported using transcoding by 3rd party plugins.

MPEG-4 format (the usual container format with extension mp4) is a comprehensive standard aimed at handling multiple different sorts of media streams in the same file - so it can have video, audio tracks with chaptering, ads, metadata and subtitles - most of which is overkill for simple audio files with cover art and a bit of metadata and it does nothing to improve / degrade audio quality.

**d6jg** · 2021-02-02, 12:16

FLAC 100% - If you subsequently want to convert from lossless to a lossy format you can easily do so but you can never convert from lossy to lossless without loss of quality. Also if you ever want to re-create a CD at its full quality you can easily do so from FLAC but not from a lossy format.

To answer an earlier question - FLAC can store cover art in the file. Its not necessary for LMS if there is a single folder.jpg etc but it does work

Note. LMS will read the cover art from the first track in the album if its is embedded in preference to folder.jpg / cover.jpg.

**rkrug** · 2021-02-02, 13:45

Which file format to use: mp4 (applelossless) or flac?

> On 2 Feb 2021, at 13:16, d6jg <d6jg.9wg0jz (AT) no-mx (DOT) forums.slimdevices.com> wrote:
>
>
> FLAC 100% - If you subsequently want to convert from lossless to a lossy
> format you can easily do so but you can never convert from lossy to
> lossless without loss of quality. Also if you ever want to re-create a
> CD at its full quality you can easily do so from FLAC but not from a
> lossy format.

Definitely true - but ALAC (Apple Lossless Audio Codec (ALAC)) is lossless - so no difference in that respect.

>
> To answer an earlier question - FLAC can store cover art in the file.
> Its not necessary for LMS if there is a single folder.jpg etc but it
> does work
>
> Note. LMS will read the cover art from the first track in the album if
> its is embedded in *preference *to folder.jpg / cover.jpg.
>
>
>
> VB2.4[/B] STORAGE *QNAP TS419P (NFS)
> [B]Living Room* Joggler & Pi4/Khadas -> Onkyo TXNR686 -> Celestion F20s
>
> *Office* Joggler & Pi3 -> Denon RCD N8 -> Celestion F10s
> *Dining Room* SB Boom
> *Kitchen* UE Radio (upgraded to SB Radio)
> *Bedroom (Bedside)* Pi Zero+DAC ->ToppingTP21 ->AKG Headphones
> *Bedroom (TV) & Bathroom* SB Touch ->Denon AVR ->Mordaunt Short M10s +
> Kef ceiling speakers
> *Guest Room* Joggler > Topping Amp -> Wharfedale Modus Cubes
> Everything controlled by iPeng & Material on iOS
> ------------------------------------------------------------------------
> d6jg's Profile: http://forums.slimdevices.com/member.php?userid=44051
> View this thread: http://forums.slimdevices.com/showthread.php?t=113836
>
>

**BJW** · 2021-02-08, 06:24

I use MP3 and ALAC. I used to use flac, and it's great, and the crc bit flip checks is def in its favor, BUT I switched to ALAC bc ALAC is easier to handle both tagging wise, and natively with anything Apple. I rarely find anything that can't handle ALAC natively, but most Apple stuff won't do flac.

Announcement

Which file format to use: mp4 (apple lossless) or flac?

Which file format to use: mp4 (apple lossless) or flac?

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment