Convert AAC files to MP4 files?

[DTS]

Since MP4 files use AAC for the audio, it should be possible to convert AAC files to MP4 with say a blank black frame for the video and keep the AAC audio untouched (no further compression).

This is how I get videos of tunes saved as from Youtube where they just had a still image for the video. These will play on my PSP in the Music section (course they'll play in the video section, too).

See, I rip the stream (record the file) of an internet radio station often that streams AAC files. The trouble is, AAC files won't play on my PSP but MP4 files, which have AAC inside them as the audio, will.

I've searched many times before for a program that will convert AAC files to MP4 files, with the AAC used as the audio and just a blank black frame for the video (or whatever picture I'd choose, though a blank black frame would be my choice). I've found nothing but bloated programs that do not do what they claim to and barely come close to what I want a program to do.

Does anyone know a program that can do something like this? Closest I can imagine is a fully fledged video editing program like Adobe Premiere (which I've not used since the vids days, back when they were really popular). I'm hoping there's a simpler program so I don't have to go through all that resource-hungry video editing stuff just to do what essentially is to change an audio format.

[Survivor]

Super encoder

[bitWISE]

MP4 doesn't exclusively use AAC for audio (not that that matters for your purposes). MP4 also has an audio only version usually called MP4A. There are hundreds of AAC to MP4 converters out there.

If you don't have a ton of converting to do, I like to use this site http://media.io/

But you rip music off youtube?

[Plan B]

somewhere else

[DTS]

I tried that Super Encoder program and there doesn't seem to be any way for it to do what I wanted. It will accept AAC as input; ouput as MP4 but that MP4 file is unplayable. I tried setting it to ignore the video side of it, tried dragging-and-dropping a suitable rezzed image file hoping it would act as the video source, but both ways (making a total of 3 ways) gave an unplayable file. Am I missing the special quirky way of using the program? Care to shed some light on it Survivor, please?

[mrd]

If you're ripping radio streams, just set your sound card to record "what you hear" and get a simple recording program (Goldwave, etc.) and record what you need and save it out as MP3/WAV. If your sound card doesn't support this functionality, go buy a normal sound card and ditch the embedded shit. Otherwise, you could perhaps use Cubase's "replace audio in video" functionality and use a base black-screen video and then inject various audio files into it.

Furthermore, you could also just use a hex editor to do the work. An MP4 file is just a container with a video and audio portion and header information for each portion which tells the program how large the data block is, which codec to use, and various descriptive information for the user. Open a file and then go find some webpage that tells you about the MP4 structure. You want to find where the data blocks are, then you can manually inject whatever audio you want into that block. Make sure you update the header for that block accordingly so that it feeds the correct size of the data block to your PSP software, otherwise the file will be corrupt.