Tue Apr 15, 2014 3:38 pm
Tom,
I made an assumption that since SC need not use something like MPEG, which codes both Video and Audio, there would be more headroom. I have no research other than my own ear to justify such a statement.
An example I did find suggest strongly that the user, the 'uploader' rushes the process and therefore the entire data package is not delivered before YT processes. The upload is stopped and goes from there, ergo, bad audio?
In the spirit of KISS;
An MP3 download as compared to a 'standard' CD (Compact Disc) has a ratio of around 11:1 compression.
- A few definitions are needed before going any further;
"Bit" is in two flavors here, the difference in 16 bit depth and 24 bit is pretty big. This particular 'bit' is called "Bit Depth". An decent analogy would be just how thick a book would be, and the increase goes like this;
16 bit depth = 65,536 possible levels (pages)
For each 'bit' of resolution we double the depth so,
24 bit depth = 16,777,216 possible levels (pages)
Big, big difference.
Now, add in "TIME" and we get 'sample rate' or the kHz we keep bringing up. A standard CD uses 44.1khz at usually 16bit depth. Simply put, that's how many times we can 'slice' the audio per second, the higher the number the more 'slices' lower, the less. Or, at 44.1kHz we can 'slice' 44 thousand 100 each second, at 96kHz, that's 96 thousand, at 22.05 it's 22 thousand and fifty and so on.
Last ingredient - sampling. or "Bit Rate" - how much data is required to transmit said file.
File Sizes For Stereo Digital Audio;
Bit Depth Sample Rate Bit Rate 1 Stereo Minute 3 Minute Song
16 44,100 1.41 Mbps 10.1 MB 30.30 MB
16 48,000 1.46 Mbps 11.0 MB 33.00 MB
24 96,000 4.39 Mbps 33.0 MB 99.00 MB
mp3 128 k/bit rate 0.13 Mbps 0.94 MB 2.82 MB
We have had several threads on these issues before but I don't always remember the details unless I have actually used the ideas at the time.