ffmpeg mp3 file crop and reduce bit rate

FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec - the leading audio/video codec library.

Now i am used this ffmpeg tool to crop the mp3 song for particular minutes and change the quality of the song.

CROP:

• ffmpeg -t and -ss (output-only) options are now sample-accurate when trans-coding audio
• 1 is the starting point of the mp3 and 120 is the number of seconds   crop the song.
• input.mp3 is your input file name and output.mp3 is the result store that name  in the same path.

Example:  exec("ffmpeg -ss 1 -t 120 -acodec copy -i input.mp3 output.mp3");

Change the bit rate:

• Convert mp3 to lower bitrate using ffmpeg
• 96k is the bit rate. if you want like 126k ,320k just need to adjust that.

Example: exec("ffmpeg -i input.mp3 -ar 44100 -ab 96k -f mp3 output.mp3");