Quote:
Originally Posted by leeperry
Or you can do it in your decoder in realtime and avoid double lossy reencoding.
|
@leeperry -
There is no double-lossy encoding here, that was made sure of. Ffmpeg is muxing 5 channels to 2 channels - and then passing that to qaac as a 32-bit float PCM (raw) data stream. It was also verified that the actual libdts module returns 32-bit float PCM - so there is no dithering happening when the data is being passed from ffmpeg libdts decoder to qaac aac encoder. The lossy encoding is happening only once - and that is by QuickTime AAC (qaac command line).
This is why we are explicitly telling ffmpeg to "-acodec pcm_f32le".
Yes you could do the AAC encoding with ffmpeg - but I hydrogenaudio listening tests show that the best encoder is Quicktime AAC encoder.