Amazon Polly will produce mp3 and ogg, sampled at 8,000 Hz, 16,000 Hz and 22,050 Hz.
Should I start with the highest rate using either of these formats and convert with sox to which format? Is sln the best choice of output file format?
Does it make any sense to sample at a higher rate than the input file when using sox? For example, If I used an ogg file as input downloaded from Amazon Polly at 22,050 Hz, could I convert it at 48,000 Hz?
I notice that asterisk has the following file format.
slin48 ogg_opus opus
What does this mean and does this mean I can convert the ogg input file to sln at 48,000 Hz and rename it to sln48?
Should I also convert to other file formats like G729 and ulaw and if so, at what sampling rate? I’d like to produce the highest possible quality.