1789321 - AAC m4a files getting renamed to .mp4

Status: REOPENED

(Core :: Audio/Video: Playback, defect)

Description

[jherbertbpc]

Attachment: Safari 15 Correctly Downloading m4a file-type.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:104.0) Gecko/20100101 Firefox/104.0

Steps to reproduce:

Download of aac m4a files

Actual results:

Are rendered/appended as .mp4

Expected results:

Files should download as .m4a files to import to iTunes
PLEASE Note I submitted more full details at
https://bugzilla.mozilla.org/show_bug.cgi?id=1778071
not noticing the version of the bug report

Comment 1

[jherbertbpc]

Attachment: Firefox 104 Appending Wrong File-Type.png

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::File Handling' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 3

[Simona Badau, Desktop QA]

I could not reproduce this issue using the latest Nightly 106.0a1 nor Firefox 104.0.1 on macOS 11.6 - .m4a files are properly downloaded on my end.

Jherbertbp, please can you confirm whether you reproduce this issue using Firefox in safe mode or with a new profile?
http://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
http://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Comment 4

[jherbertbpc]

I have not tried safe mode yet, but I have tried a brand new user account, with same results.
attaching a screenshot, for what it's worth

Comment 5

[jherbertbpc]

Attachment: System Specs + Firefox 104.png

Comment 6

[jherbertbpc]

Attachment: New User Screen Shot 2022-09-06 at 11.43.27 AM.png

Comment 7

[jherbertbpc]

By the way, this anomaly has occurred on MBPro 2015 running Mac OS Sierra, and MBPro 2017 Mac OS Big Sur and MBPro 2015 Mac OS Monterey.
Safari in each case does not change the file-type. And the proprietor of the website in question confirms the files are coded as .m4a

Comment 8

[jherbertbpc]

Safe Mode does not mitigate the issue I am having

Comment 9

[jherbertbpc]

(In reply to jherbertbpc from comment #8)

Safe Mode does not mitigate the issue I am having

Sorry I am not adept at this bug report format.

To add
I am not seeing anything in Firefox > Settings > Privacy&Security > Applications that indicate
a cause, or a remediation to the odd behavior.

Comment 10

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:Gijs, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 11

[jherbertbpc]

Just an update in case there's interest
FireFox 104.02 and 105 continues the anomaly for me. Downloading
m4a files as mp4, for the website previously illustrated.
(side note: perhaps for another day: the latest FF updates to 104.02 and 105
were a bit of a fiasco ,,, but resolvable by signing in again in order
to sync settings)

Comment 12

[mod4xbox]

I'm also seeing this behavior. Came here from a DuckDuckGo search trying to find a solution to my problem (no issues with Chromium based browsers).

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:105.0) Gecko/20100101 Firefox/105.0

Steps to reproduce:

1. Download an AAC m4a file
2. File is saved as .mp4

Expected results:
Files should be saved as .m4a files. I thought it was my fault not specifying the correct mimetype, but no.

Comment 14

[:Gijs (he/him)]

This really needs better steps to reproduce, as QA already tried (comment #3) and was unsuccessful. Please provide a direct link to a file that reproduces the problem, or attach one to this bug. I would have hoped that bug 1772988 helped here but it sounds like it did not, as that bug is fixed in 105 and comments here suggest this is still happening with 105.

Comment 15

[jherbertbpc]

This is going to be difficult to giver further clarifying information.
The files are from a subscribed to audio podcast site, where the files are posted
as m4a. My observation, confirmed only by the previous screenshots: Firefox is changing the files at this particular site to mp4 upon download. But this may not be widespread bug at all ...
and may have something to do with how Firefox handles files from this one site.

I have tried single file m4a downloads from Bandcamp and the files
are -not- changed to mp4.

Comment 16

[Alastor Wu [:alwu]]

Could you try Firefox 106? This issue might be fixed by bug 1787159. In addition, it would be helpful if you can provide adirect link for those files get changed the extension.

Thanks.

Comment 17

[:Gijs (he/him)]

Without further details I don't think we'll be able to make further progress here. We hope the fixes in 106 were sufficient - it will be released next week.

Comment 18

[jherbertbpc]

Thanks for the various comments/responses.
Guess we should close the bug thread as the only way to reproduce or test for it
would require subscribing to the podcast service.
The host has advised to simply use Safari instead of Firefox.
...

Comment 19

[akb95]

It also happens for files uploaded to discord, which is probably easier to test.

Comment 20

[jherbertbpc]

Just to add some belated follow up, which I believe I may have added on another posting that contained
a similar discussion
On my previous test with a beta version I believe, of Firefox 106 (I think it was 106 0a1 about a month ago same issue occurs.
I have not tested any later version of the 106 Beta, if there is one

Comment 21

[:Gijs (he/him)]

(In reply to akb95 from comment #19)

It also happens for files uploaded to discord, which is probably easier to test.

Can you provide more detailed steps, and perhaps a sample file with which this happens?

Comment 22

[akb95]

https://cdn.discordapp.com/attachments/488609212415344641/993806313152856094/and_I_think_to_myself_what_the_fuck.m4a

An example file, I have others but I cannot share them for practical reasons.

Comment 23

[Masatoshi Kimura [:emk]]

I could reproduce it with a fresh profile on Firefox 105.0.3 on Windows 10 22H1. STR: just click the link in comment #32.

Comment 24

[Neil Deakin]

The file in comment 22 is sent as fairly generic audio/mpeg so we guess that it is video/mp4. The patch in bug 1782366 adds .m4a as a valid extension for video/mp4 so fixes the bug for this particular case. Note though that the file in comment 22 appears to be an audio only file though.

Comment 25

[jherbertbpc]

Couple of follow up points/questions, as most of the tech details are over my head

• Comment: I should have named this post AAC m4a files getting Converted to .mp4 as I had found that a simple
re-tagging of the mp4 file to m4a did Not revert it to the correct format, files stayed as video files
Firefox is not simply renaming but converting the files upon download.
I could fix the situation by either downloading from Safari, or ripping the mp4 file into an m4a file in iTunes

• Question: What circumstance in Firefox coding would "tell" the browser to convert a file
(I have had assurances that the files in questions are formatted as m4a acc (enhanced) i.e. like podcast format.

• What might be happening at a specific website that elicits a file to be converted at download?
For instance Firefox is not converting m4a audio files into mp4 files from Bandcamp
Which makes me wonder what might be happening to, or inherent in, files that are encoded with all
the Podcast coding stuff

just wondering

Comment 26

[:Gijs (he/him)]

(In reply to jherbertbpc from comment #25)

Couple of follow up points/questions, as most of the tech details are over my head

• Comment: I should have named this post AAC m4a files getting Converted to .mp4 as I had found that a simple
re-tagging of the mp4 file to m4a did Not revert it to the correct format, files stayed as video files

Can you explain what you mean by "stayed as video files" - what other software claims these are video files still after changing the file extension?

Firefox is not simply renaming but converting the files upon download.

Paul, can you confirm if there is anything in Firefox that would do this? I don't think so...

Reporter: it would be useful to confirm what file you're seeing this with and that you can reproduce this with a clean Firefox profile. I don't think Firefox has code that changes downloaded files like this.

The file in comment 22 can be manually renamed to m4a just fine, as far as I can tell.

(In reply to Neil Deakin from comment #24)

The file in comment 22 is sent as fairly generic audio/mpeg so we guess that it is video/mp4. The patch in bug 1782366 adds .m4a as a valid extension for video/mp4 so fixes the bug for this particular case. Note though that the file in comment 22 appears to be an audio only file though.

Thanks Neil. I guess we'll need the fix from bug 1782366 to land to address this. I'll ask what the hold-up is over on that bug.

Comment 27

[jherbertbpc]

           Re: Can you explain what you mean by    ...  "stayed as video files"  ...

In my particular experience:
Firefox in not renaming them per se, meaning you cannot simply change the file to its correct type by appending .m4a
The files are converted immediately at the download process from aac m4a files into mp4 video files with
QuickTime as the default app
The only way I have found to correct the file is to either download using Safari, or converting the file in iTunes

      Re:  reproduce this with a clean Firefox profile.

Yea, I think, somewhere, I had reported this
• deleting Firefox completely app, and associated Application Support files and caches etc
• creating a new User, downloading Firefox and thusly
-- confirmed similar results

        Re: I guess we'll need the fix from bug 1782366 to land to address this. I'll ask what the hold-up is over on that bug

Just add to that comment, I don't know how wide spread this is, it seems to happen at one website for me, although I
believe there are reports here, or at a similar thread of this "bug" ... ... It it's not wide spread is it a bug??

Comment 28

[Masatoshi Kimura [:emk]]

you cannot simply change the file to its correct type by appending .m4a

I guess you do not flip on the “File name extensions” option in File Explorer.

Comment 29

[jherbertbpc]

(In reply to Masatoshi Kimura [:emk] from comment #28)

you cannot simply change the file to its correct type by appending .m4a

I guess you do not flip on the “File name extensions” option in File Explorer.

Yes, correct, I was explaining that in relation to two issues here in this thread

One: that my original subject, and perhaps other similar postings elsewhere, the subject heading is in error
Two: in response to the request for clarification of what I meant by "stayed as video files"

The point being Firefox is, indeed, not simply "renaming" these files but actually converting
m4a files on the fly at one or more websites.
In my original attempt to investigate and fix the issue I tried, simply appending what was supposed to
be the Correct file type which led me to the discovery that Firefox is not just changing the name but
actually converting one specific type of AUDIO file into a video file.

Still a mystery but, apparently not very wide spread.

Comment 30

[Masatoshi Kimura [:emk]]

(In reply to jherbertbpc from comment #29)

In my original attempt to investigate and fix the issue I tried, simply appending what was supposed to
be the Correct file type

You can't change file extension unless you turn on "Show file name extensions" option.

When you see "and_I_think_to_myself_what_the_fuck" on File Explorer, the file name is internally "and_I_think_to_myself_what_the_fuck.mp4". When you append ".m4a" to "and_I_think_to_myself_what_the_fuck", the internal name will become "and_I_think_to_myself_what_the_fuck.m4a.mp4". The extension is still ".mp4". It does not have to do with Firefox.

Comment 31

[jherbertbpc]

I am not quite sure of your whole point.
All I know is that Firefox CONVERTS m4a files immediately upon download at one, or possibly more websites.
On a Mac you can append anything you want onto a file. Does it "change" them into that file type, no.

If the file had not actually been CONVERTED, adding the CORRECT file extension would have allowed
proper handling of the file.... i.e. "fixed" the problem

To reiterate the point
FIREFOX is converting files on the fly, not simply, as you point out, changing it Name

thus, still a mystery that has only, and exactly, to do with Firefox... and apparently Firefox only...
as other browsers,... well at least Safari, do not suffer this phenomenon
I have a suspicion that Chrome will not render this anomaly,... but I will check that shortly.

Comment 32

[jherbertbpc]

Update, I have verified that Chrome does not display the anomaly of Converting
aac-m4a files into .mp4 files.
Now I shall search tutorials on how to remove Chrome from my laptop
;-))

Comment 33

[:Gijs (he/him)]

(In reply to Masatoshi Kimura [:emk] from comment #23)

I could reproduce it with a fresh profile on Firefox 105.0.3 on Windows 10 22H1. STR: just click the link in comment #32.

I've confirmed this case, at least, is fixed on current nightly, with the fix from bug 1782366.

Reporter, could you try using a "nightly" build from https://nightly.mozilla.org/ to check if the problem you're seeing is resolved there? If so, we can close this out - the fix will ride to release with version 108, currently due for release in just under 5 weeks from now.

Comment 34

[jherbertbpc]

the current Nightly 108.0a1 (2022-11-09)
does not address the issue for me
aac_.m4a files are still downloaded as aac_.mp4

Comment 35

[:Gijs (he/him)]

(In reply to jherbertbpc from comment #34)

the current Nightly 108.0a1 (2022-11-09)
does not address the issue for me
aac_.m4a files are still downloaded as aac_.mp4

Do you have any publicly available links that reproduce this issue? If not, perhaps the owner of the "ambient zone" site where you see this can make a short test file available, or provide us with private test account details via email? (you can use gijs at mozilla.com for this)

Comment 36

[jherbertbpc]

Good point, and no.
I have _ not _been able to reproduce this, for instance with a file from Bandcamp, or individual file from Internet Archive for example
I have not had the time to source another aac/m4a "enchanced" audio file ... by which I assume this means
it's a podcast style encoding with chapters etc. ... enhancements?
I doubt I could easily find a podcast easy/free to download that is an acc encoded, with chapter enchancment.
I thought there was another report or example from someone on some files from reddit, but that was in an other (duplicate?) thread

Plus, last I communicated with the podcaster, his advice was ... just use Safari

Such a rare problem.
I would recommend archiving this thread ... a minor mystery that cannot conveniently solved. Sorry to say

Comment 37

[jherbertbpc]

I am not sure if I was supposed to set a severity.
My access does not allow that, but I have updated some version specs on the report change FF 104 to 106, on Mac OS

Comment 38

[jherbertbpc]

Appears this bug report was reopened
Last I checked the bug still exists for certain sites
Firefox changes m4a file downloads into mp4 file type
Feel free, someone, to archive the bug thread please