I primarily use Audacity to create ringtones for my iPhone, and I’ve been using the MP4 with the .m4r file type to export them so they will be compatible. For some reason they’ve been exporting in 192 kbps even though I have the quality up to 500.
Two questions: is there another way to change the preference to a higher quality and is there another file type I can export as to give me higher quality and be compatible as a ringtone?
According to iTunes when I export it to that the bitrate reads as 192. I can tell that the quality is less than that of my old ringtones that I’ve made in the past because the new ones seem to have quite a bit of distortion.
Audacity does not support MP4 directly but relies on FFmpeg for the conversion. It is very difficult for open source programs (such as Audacity) to support closed / proprietary formats (such as MP4) because of license / patent issues. As Audacity is free, we can’t provide a commercial encoder for these formats, so we have to rely on free third party transcoders (and leave the question of whether the encoder is strictly legal in the user’s country, down to the user. See: https://www.ffmpeg.org/legal.html). The issue is further complicated by changes that occur frequently in FFmpeg that often break compatibility with older versions.
Given all this, the “best” solution for proprietary formats would be to either:
a) Export from Audacity in WAV format, then use a fully licensed commercial encoder to convert the WAV file to the required format.
b) Use a fully licensed commercial encoder via Audacity’s command line export option (http://manual.audacityteam.org/man/exporting_to_an_external_program.html)
c) Use a free, open format whenever possible (such as WAV, AIFF, FLAC, Ogg)
Option c is arguably the best option, but not always practical due to limited format support of other devices (such as iPhones).
Option a is probably the best option for an iPhone using iTunes to do the conversion.
That’s because the quality slider does not work with the specific AAC encoder that our recommended FFmpeg version ships with. There are multiple AAC encoders available to FFmpeg if support for those encoders is compiled into FFmpeg. All of those FFmpeg AAC encoders have one problem or limitation or another.
You can’t choose which FFmpeg AAC encoder to use unless you use Audacity’s command-line exporter as Steve described. And if you do that, you have choices of other commercial AAC encoders too.