File conversion failure

[rbelavich]

I am a new (beginner) user trying to convert some m4a file to mp3. About half of the assorted m4a files I have will not batch convert and produce error messages stating the following: "the file type is not supported".

These files are m4a audio tracks from CD that were ripped using the ITunes App. These audio files load and play fine in the Window Media Player. I have other m4a Audio files that the Goldwave Editor is able to convert to mp3 audio satisfactorily.

Additionally, when I try to open any m4a files in the Goldwave Audio Editor (files that converted properly and files that did not), the file/s do not seem to load any audio data and show flat lines on the screen.

Any help with this situation would be appreciated.

Thanks,
rbelavich@gmail.com

[DougDbug]

I'm not sure what the problem is but if you are just converting without editing, try TAudioConverter. It's a lot easier... Once you've setup the output format & output location it's just drag, drop, and click.

...I don't know where GoldWave's MP4/AAC decoder comes from, but I assume it's from Microsoft. If you have an older operating system or older version of GoldWave, I think you have to install QuickTime and then GoldWave uses its CODEC.

Some older downloaded iTunes (before 2009) were copy-protected but that shouldn't apply to anything ripped from CD.

These files are m4a audio tracks from CD that were ripped using the ITunes App.

If you still have the CDs you are doing an unnecessary lossy-to-lossy conversion. You may not hear any quality loss, but there is potential quality loss with each generation of lossy compression. (I assume you know that CDs are uncompressed but MP3 & MP4 are both lossy compression.)

I think you can set up iTunes for ripping directly to MP3. Lately, I've been using CueRipper and before that I used EAC, but EAC can be tricky to set up.

While we're on the subject... If you open a compressed file in GoldWave (or any normal audio editor) it gets decompressed. If you re-save the same (or different) lossy format you going through another generation of lossy compression. If you want a lossy format MP3, MP4, AAC, etc.), it's best if you can compress once as the final step after editing.

Thanks,
...@gmail.com

FYI - It's "risky" to post your email on a public forum where it can be harvested by a spam-bot.

[DewDude420]

It's probably a malformed header; it wouldn't shock me that iTunes used something non-standard.

Your m4a files are technically "container" files; it merely "contains" a format and contains information about the stream. WAV files are technically container formats since they can contain any number of codecs. M4A files though, typically only contain an AAC audio stream.

The best way to fix this is to extract the raw AAC data from the files; though I'm not 100% sure right now if Goldwave will open a .AAC file containing a raw AAC stream. What I've had to do in the past is demux all my malformed m4a files; then remux the AAC streams in to new m4a files.

There are loads of utilities that'll do this. I think MPEG StreamClip provides a GUI for doing it all.

[GoldWave Inc.]

The files could be lossless M4A, which may not be fully supported depending on the version of GoldWave you are using and the version of Windows you have. If you have the latest version of GoldWave on Windows 10, then it should be able to open them. What attributes are shown in GoldWave's status bar after you open one.