.m4a (AAC) files created in WavePad or Switch converter will not open in Windows Media Player or MusicBee

dazkgoodwin

I'm saving .m4a files in WavePad and also in Switch converter, however there is something corrupt about the file structure/container, as they open in VLC, but will not open in Windows Music Player or MusicBee. The files correctly contain AAC encoded audio, but they do not open as the file is corrupt - resaving via VLC's convert option (copying the audio stream and exporting out to .mp4/.m4a) repairs the structure - but this loses the id3 tags.

Is this is known bug? I bought the packaged of both mostly to edit audio and save as .m4a packaged AAC files, so the software is unusable unless this is fixed

borate

Amarillo.m4a Sign in to play and right-click | download.

This test Mp4a file opens in both Windows Media Player and WMP Legacy, as well as via Firefox browser. Don't have Music Bee installed.

Missing codec?

dazkgoodwin

The Windows 11 Media Player error message is (not legacy Windows Media Player) - 'It's encoded in mp4a formatted which isn't supported'

Windows Media Player Legacy reports errors and will not play .m4a files (AAC) encoded with Switch or WavePad.

The exact same encoding settings do work however, if the file is exported to an .aac extension instead, however this does not support the id3 tags. This is the codec info:

Format : MPEG-4
Format profile : Base Media
Codec ID : isom (M4A /mp42/mp41)

Audio that typically plays in media player and musicbee has these tags:

Format : MPEG-4
Format profile : Apple audio with iTunes info
Codec ID : M4A (M4A /mp42/isom)

borate

The test file above, saved as M4a plays here as described. Upload a file that fails and someone will check it out...

Upload to a free server, such as Google Drive or MS OneDrive, right-click the link and Share. Copy the result and paste it here or to me in a Private Message via the mail envelope in the top-right corner of this forum. When using Google Drive, if necessary change "restricted" to "anyone with link can view.**

dazkgoodwin

.m4a file generated in NCH software (not playable in media player, music bee etc.)

borate

In Google Drive, click SHARE | SHARE and change "restricted" to "anyone with link can view."

dazkgoodwin

done

dazkgoodwin

The following is the very same file, converted via VLC (which removes tagging). This version plays fine, but with the slightly different media Codec ID info below. The audio stream is identical, as VLC was used to copy the audio stream, no re-encode, so it's just the package/codec id that's different

https://drive.google.com/file/d/15lgKP53KRfFe1GvL3lU05t0cMTOCB-h6/view?usp=sharing

Format : MPEG-4
Format profile : Base Media
Codec ID : isom (mp41/avc1)

borate

The file you uploaded threw that error.

However, when saved as an M4a in the latest Wavepad version, plays in Windows Media Player, just as my test file did. The result...

4 Forbidden Colours.m4a_WP.m4a

dazkgoodwin

Very strange. I've also converted the file using ffmpeg command line, again, copy codec from .m4a to .m4a, that changed the codec ID to below, and again, it played (but no mp42 in the codec id - it seems to be that stopping my media player and musicbee from playing the file). For some reason the codec id generated in Wavepad is not working, but I will install any updates to Wavepad to be sure it works. ffmpeg preserves the id tags so that will serve as a workaround for now.

Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/mp41)

borate

You might want to query NCH on that. But the Wavepad export does indeed succeed in all players tested here.

dazkgoodwin

Interestingly, if I export to Average bitrate (ABR), which only goes to 192kbps, it plays fine, but CVBR and VBR produce files that I can't open.

ABR also generates a different codec ID, again, there's no mp42:

Codec ID : isom (isom/iso2/avc1/mp41)

dazkgoodwin

Reported to NCH. This thread quoted as well. Hopefully they can shed some light, but knowing that ABR files work, but CBR and VBR , and it's the 'mp42' in the codec ID header that seems to be the issue will help the programmers/developers debug this.