Friday, October 31, 2014

Remastering an audio track from multimedia file using Open Source tools

I finished the multimedia file manipulation tutorial. In this case I show the audience how to effectively and at one's best attempt remaster a neglected audio track from a multimedia file found at coursera's website. Any other unheeded multimedia file bearing a lacking audio track may be used, but the filters would have to be applied with slightly different parameters. Notice it does not make any miracles, it simply improves a low quality recorded voice track.

We use the famous Open Source audio software Audacity to apply Noise Removal, Compress Dynamics, Equalization, Zero Cross, Silence and other filters. After the voice track is improved, we set a series of parameters for FFmpeg:

ffmpeg.exe -i path/video_filename -i path/audio_filename -map 0:0 -map 1:0 -vcodec copy -acodec libmp3lame -b:a 128k -ac 2 output_filename.mp4 It will show series of statistics from the processing being computed in regards to the frames, quality, time, size, etc. Once it finishes the processing, the output file will be ready to be played by default on the bin directory of FFmpeg.