Early MPEG Layer III encoders used what is now called Constant Bit Rate (CBR). The software was only able to use a uniform bitrate on all frames in an MP3 file. Later more sophisticated MP3 encoders were able to use the bit reservoir to target an average bit rate selecting the encoding rate for each frame based on the complexity of the sound in that portion of the recording.
এনকোডার কি উপর প্রতিটি ফ্রেম জন্য এনকোডিং হার ভিত্তি করে?
the complexity of the sound