Media players often report the bitrate of the audio file playing.
1411 kbits is the value you will see when playing a uncompressed lossless format like WAV.
The calculation is simple;
Number of Channel * word length * sample rate
Playing CD quality is playing 2 channels with 16 bit word length and 44100 samples per second or 2*16*44100=1411200 bit/s or 1411 kbs.
The bit rate of the audio file says nothing about what is send to the DAC.
If you use up-sampling e.g. set Win to output 24 bit at 96 kHz, you still see 1411 kbs but you are sending 2*24*96=4608 kbs to the DAC.
If you play FLAC you see most of time a value between 700 – 800 as FLAC compresses 40-50%.
This is the bitrate of the compressed file.
However it is lossless so when expanded to raw PCM you have the full unaltered original 1411 kbits.
The bitrate of a lossless compressed format indicates the amount of lossless compression.
The bitrate of a lossy file indicates the amount of information discarded.
If a MP3 is created as 320 kbs CBR this indicates how much of the original information is discarded.
Indeed MP3 is like magic, at 320 the bitrate is reduced from 1411 to 320 kbs, it throws out ¾ of the information and still most of us won’t hear a difference.
Not to be mistaken for a absence of differences,
They are there but very subtle.
If you want to hear them you do have to hunt for them e.g. music by Kraftwerk.
Why do they use the bit rate of the file instead of the actual playback rate?
The answer is simple, the actual rate is not very informative.
You rip a CD to WAV, FLAC and 320 CBR MP3.
To play them they must be converted to something a DAC does understand, raw PCM.
This will yield the same value regardless of the file format e.g. 2 channel 16 bits 44.1 kHz PCM
1411 kbits is the value you will see when playing a uncompressed lossless format like WAV.
The calculation is simple;
Number of Channel * word length * sample rate
Playing CD quality is playing 2 channels with 16 bit word length and 44100 samples per second or 2*16*44100=1411200 bit/s or 1411 kbs.
The bit rate of the audio file says nothing about what is send to the DAC.
If you use up-sampling e.g. set Win to output 24 bit at 96 kHz, you still see 1411 kbs but you are sending 2*24*96=4608 kbs to the DAC.
If you play FLAC you see most of time a value between 700 – 800 as FLAC compresses 40-50%.
This is the bitrate of the compressed file.
However it is lossless so when expanded to raw PCM you have the full unaltered original 1411 kbits.
The bitrate of a lossless compressed format indicates the amount of lossless compression.
The bitrate of a lossy file indicates the amount of information discarded.
If a MP3 is created as 320 kbs CBR this indicates how much of the original information is discarded.
Indeed MP3 is like magic, at 320 the bitrate is reduced from 1411 to 320 kbs, it throws out ¾ of the information and still most of us won’t hear a difference.
Not to be mistaken for a absence of differences,
They are there but very subtle.
If you want to hear them you do have to hunt for them e.g. music by Kraftwerk.
Why do they use the bit rate of the file instead of the actual playback rate?
The answer is simple, the actual rate is not very informative.
You rip a CD to WAV, FLAC and 320 CBR MP3.
To play them they must be converted to something a DAC does understand, raw PCM.
This will yield the same value regardless of the file format e.g. 2 channel 16 bits 44.1 kHz PCM
