Export creates 0 KB file

[Schmagagled]

I'm trying to import PCM RAW ringtones and export them as .M4R (same as M4A).

FFmpeg is installed and so is LAME.

I import the raw file as 8000, mono, little endian (or no endian).

The file plays in Audactity. So no problems there.

I chose the export menu item and have tried both the default M4A for mat and also renaming the extension to M4R so I can bring it directly into iTunes.

The first file saved fine and has a 9kb size.

Every subsequent ringtone I try to import saves with a 0kb file size.

Anybody got any idea what I'm missing here?

Thanks,

S.

[steve]

Audacity does not appear to currently support export to AAC at 8kHz.

If you set the "Project Rate" (lower left corner of the main Audacity window) to 44100 before you export, then it should export.
Why do you need these files in .M4R format? Is it OK if the sample rate is changed to 44.1 kHz?

[Schmagagled]

Well that would certainly explain it.

I haven't looked up what the rate is that iPhones support for ringtones. I hadn't really though about it.

Will 44khz work?

S

[steve]

For use with an iPhone I'd suggest that you just export from Audacity as a WAV file, then use iTunes to convert the WAV to M4A and synchronise you iPhone. Apple has a few quirks of its own about AAC files, so I think iTunes would be the best program for doing the encoding.

Here's some information on a forum that may help http://noobforums.com/forums/showthread.php?t=12764

[Gale Andrews]

I'm trying to import PCM RAW ringtones and export them as .M4R (same as M4A).
I import the raw file as 8000, mono, little endian (or no endian).
The file plays in Audactity. So no problems there.
I chose the export menu item and have tried both the default M4A for mat and also renaming the extension to M4R so I can bring it directly into iTunes.
The first file saved fine and has a 9kb size.
Every subsequent ringtone I try to import saves with a 0kb file size.

First off, 8000 Hz .M4R files are fine in the "Ringtones" section of iTunes, so I assume them to be accepted in iPhone (though I do not own one). I think this is a more accurate list of iPhone supported formats (sample rate support being whatever sample rate the format supports).

What URL exactly did you get FFmpeg from, and what version of Audacity are you using (Help > About Audacity)? I cannot replicate your issue at all on Windows with 1.3.12 or 1.3.14-alpha using our official FFmpeg 0.6.2 from the Beta FAQ (or using the previous official FFmpeg 0.5). Using File > Import RAW, I have tried importing a .WAV headered file and a headerless .RAW file (signed 16-bit PCM). If you have an example of a RAW file that reproduces this issue (in Audacity and FFmpeg supplied by us) please attach it.

If you export M4A (or M4R) on Linux Ubuntu at 8000, 11025 or 16000 Hz with the Ubuntu-supplied FFmpeg, then the files will be 0 kB. Using FFmpeg at the command line outside of Audacity exports correct files, so I assume this is an issue with how Audacity interfaces with the native FFmpeg AAC encoder that comes with the Ubuntu FFmpeg (libfaac is used for AAC export by our FFmpeg for Windows installer). I have not tested that by building FFmpeg on Linux with libfaac enabled though.

Also the AAC "Quality" slider on Ubuntu has no effect for AAC exports when a file is actually exported, but I expect this is actually an issue with our slider and not dependent on the particular AAC encoder. There is no issue on Windows with the AAC "Quality" slider.



Gale