Introduction
Loudness is a subjective measure of audio, the loudness indicates how loud a sound is perceived by a human being in every moment.
The main objective of the project is to explore the normalization of audio levels in the media industry, which is a relevant issue nowadays. Many broadcast organizations around the world are concerned about this problem and they have published many papers and standards that will be analyzed in this project, some of those organizations are: European Broadcasting Union (EBU), International Telecommunication Union (ITU), Advanced Television Standards Committee (ATSC)
Different types of loudness meters have been implemented, and different programming languages have been used
Used technologies
C, C++, C#, MFC, Directshow, IIR filters, R128, A/85, TCP/IP, ITU-R BS.1770-0/1/2/3, True Peak
References
– R 128: Loudness normalisation and permitted maximum level of audio signals (08/2011)
– TECH 3341: Loudness Metering: ‘EBU Mode’ metering to supplement loudness normalisation in accordance with EBU R 128 (08/2011)
– TECH 3342: Loudness Range: A measure to supplement loudness normalisation in accordance with EBU R 128 (08/2011)
– TECH 3343: Practical guidelines for Production and Implementation in accordance with EBU R 128 (08/2011)
– TECH 3344: Practical guidelines for distribution systems in accordance with EBU R 128 (08/2011)
– R BS.1770-2: Algorithms to measure audio programme loudness and true-peak audio level (03/2012)
– R BS.1770: Algorithms to measure audio programme loudness and true-peak audio level (03/2012)
– White paper: Audio Loudness Monitoring (01/2012)
WAV file syntax specs:
– Wave file format specs 1 (http://www.sonicspot.com/guide/wavefiles.html) (02/2012)– Wave file format specs 2 (http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/WAVE.html)
Shelving filters design:
– Udo Zolzer, DAFX Book, London: Jonh Wiley & sons 2002. ISBN: 0 471 49078 4
– A/85: Techniques for Establishing and Maintaining Audio Loudness for Digital Television (04/2012)
– Microsoft Directshow SDK documentation (06/2012)
JORDI CENZANO 