On Sat, 22 Feb 2020 16:02:44 +1100, Trevor wrote:
On 22/02/2020 4:33 am, Scott Dorsey wrote:
wrote:
You are correct. The file uses ADPCM compression, I believe, so it is
not CD quality. It uses a bit depth of 4 bits, which is de-compressed
when playing to 16 bit.
ADPCM is not lossy compression at all, it is a sort of encoding method
intended to get more usable dynamic range with fewer bits but it's still
straight PCM... just not linear PCM. I had no idea you could do it with
as few as 4 bits, but 8-bit u-law encoding is typical telephone quality
today.
Yes, and he never said "lossy compression". However there is plenty of
loss already inherent in those low bit encoding schemes anyway. The
whole point of MP3 etc was to *reduce* the audible loss at low data
rates. I'm sure you know this, but the old compression Vs compression Vs
compression linguistic problem raises it's head once again.
Can you download and unzip the file
http://c-compiler.com/myfiles/a-mp3.zip
and listen to the files x.wav and x.mp3 ? Are they similar?
They are only 4 seconds in length, there is very little work involved
in listening to these two files.
I am looking for one or two more opinions as to whether the source WAV
file and destination MP3 file are similar to the ear. You might try
listening through earphones, for better clarity.
Sorry to keep harping on about this, but I am trying to obtain
re-assurance that the conversion to MP3 gives a file which is
effectively the same to the ear as the source WAV.