Hi all,
I’m having trouble with the quality of music on hold in mp3 format. Firstly i uploaded a wav fiile of the same clip and that played silence and then the mp3 sounds terrible but at least it plays sound. I guess my question is are there any specifics that i need to be aware of that could cause these issues. Is the file too big or too small or something such as this?
Any advice muchly appreciated! Have only been on elastix and asterisk for a few months.
Chris
Asterisk is very flexible in this regard and can work with many different audio formats. We have found that, in general, the most useful format to use is WAV. Files saved in this format can be of many different kinds, but only one type of WAV file will work with Asterisk: files must be encoded in 16-bit, 8000 Hz, mono format.
Recommended Prompt File Format
The WAV file format we have recommended is useful for system prompts because it is a format that can easily be converted to any other format that your phones might use without distortion, and one that almost any computer can play without any special software. Thus, not only can Asterisk handle the file easily, but it is also easy to work with it on a PC (which can be useful). Asterisk can handle other file formats as well, and in some cases these may be more suitable to your needs, but in general we find 16-bit 8-kHz WAV files to be the easiest to work with and, most of the time, the best-possible quality.
Lack of machine resources.
Generally playing MP3 in real time doesn’t make sense, as it requires a lot of processing power to degrade the MP3 to be compatible with telephone codecs. It is better to convert the files offline, in advance.