How to extract libvo_aacenc audio from an MP4 file on windows ?

[jack616]

I have a group of MP4 files I copied into MP4 a long time ago.

It seems ffmpeg no longer carries the above codec (I can only use pre-compiled versions of ffmpeg)
I'm assuming thats the codec issue as the headers are reporting codec as 0x11000000 which is non valid
but ffmpeg reported the above codec is not playable and sometimes lists it as libvo_aacenc but not always.

Apparently apple software can play this but I dont have anything that works.

This also stops many windows programs playing the files back (lav splitter breaks)

Does anyone have a good way to resolve this and get the audio converted to ac3 please?

tks
jack

[ProWo]

Windows media player or vlc can play it?

[jack616]

Nothing on windows I have recognises it -even virtualdub says there is no audio in the file at all
yet mediainfo reports duration and bitrate stream size etc
and the video portion plays fine.
there are a couple of audio section entries I dont recognise in there
Codec configuration box is reported as glbl
Alternate group is 1
Thats using mediainfolib V21.03

Also codecs are supposed to be text names not hex values.
If it was just one or two files I'd assume corruption but it isn't
as others have see that hex value reported as Format and codec Id

Audio
ID                                       : 2
Format                                   : 0x11000000
Codec ID                                 : 0x11000000
Duration                                 : 3 min 0 s
Bit rate mode                            : Variable
Bit rate                                 : 128 kb/s
Stream size                              : 2.76 MiB (3%)
Language                                 : English
Default                                  : Yes
Alternate group                          : 1
Codec configuration box                  : glbl

Report created by                        : MediaInfoLib - v21.03

[ProWo]

Try:
ffmpeg -i your.mp4 -c:v copy -c:a ac3 -b:a 320k output.mp4

[jagabo]

This site has old pre-built versions of ffmpeg archived. Try a version older than 3.0.

https://www.videohelp.com/software/ffmpeg/old-versions

[jack616]

thanks jagabo -

I found v2.0.1 has that libvo_aacenc included but ffmpeg still says codec not found

That was the only real lead I had - others have reported codec 0x11000000 but I cant seem to pin
down what it is exactly.

I'm starting to wonder if ffmpeg had a bug at some stage that just wrote this hex in when copying certain files...
I have tried a hex editor and changed it to AC3 and AAC but no luck
Increasing probesize and analyzeduration doesnt help.

[Selur]

got a sample of such a file that you can share ?

[jack616]

I'll have a look though them and find one that isnt copyright or client related tommorow.

[Selur]

Old Hybrid version from 2016 probaly can do the job, before ffmpeg dropped support for libvo_aac.

[ProWo]

https://bbs.archlinux.org/viewtopic.php?id=212944

[jack616]

Sorry everyone -it looks like the Libaac_enc thing was a miss-report from the software (I think - still unsure)

I tried to cut a number of the vids down to a reasonable size (turns out I have over 300 with this problem) but
everything I use to cut them just ignores the audio entirely or stops when t doesnt recognise it.

Also I tried mpc-hc playback and looked closer at the LAV58 report and both say they are IMA adpcm files - LAV says an unknown subtype
The "soundhandler" reported in the files (viewed with hex editor) has no text name.

Needless to say I've been trying dfferent ADPCM formats but no success.
I'm starting to think I'm never going to track this down the actual codec subtype was listed as 0x0011 but I cant track that to anything either
I have tried older ffmpegs as suggested here.

So thanks to everyone for trying but I'm going to have to put this to bed at least untill after xmas.

Have a good one
jack