Digital audio coding

2010 ◽  
pp. 26-61
Author(s):  
Jenq-Neng Hwang
Keyword(s):  
Audio Coding ◽  
Digital Audio

MPEG digital audio coding

1997 ◽  
Vol 14 (5) ◽  
pp. 59-81 ◽  
Author(s):  
P. Noll
Keyword(s):  
Audio Coding ◽  
Digital Audio

Detection of Montage in Lossy Compressed Digital Audio Recordings

2015 ◽  
Vol 39 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Rafał Korycki
Keyword(s):  
Audio Coding ◽  
Digital Audio ◽  
Tampering Detection ◽  
Detection Algorithms ◽  
Perceptual Audio Coding ◽  
Audio Recordings ◽  
Spectral Coefficients ◽  
Previous Algorithm ◽  
Audio Files ◽  
Music Database

Abstract This paper addresses the problem of tampering detection and discusses methods used for authenticity analysis of digital audio recordings. Presented approach is based on frame offset measurement in audio files compressed and decoded by using perceptual audio coding algorithms which employ modified discrete cosine transform. The minimum values of total number of active MDCT coefficients occur for frame shifts equal to multiplications of applied window length. Any modification of audio file, including cutting off or pasting a part of audio recording causes a disturbance within this regularity. In this study the algorithm based on checking frame offset previously described in the literature is expanded by using each of four types of analysis windows commonly applied in the majority of MDCT based encoders. To enhance the robustness of the method additional histogram analysis is performed by detecting the presence of small value spectral components. Moreover, computation of maximum values of nonzero spectral coefficients is employed, which creates a gating function for the results obtained based on previous algorithm. This solution radically minimizes a number of false detections of forgeries. The influence of compression algorithms' parameters on detection of forgeries is presented by applying AAC and Ogg Vorbis encoders as examples. The effectiveness of tampering detection algorithms proposed in this paper is tested on a predefined music database and compared graphically using ROC-like curves.

ISO/MPEG Audio Coding

1997 ◽  
Vol 08 (01) ◽  
pp. 69-118 ◽  
Author(s):  
Peter Noll ◽  
Davis Pan
Keyword(s):  
Phase 1 ◽  
Audio Coding ◽  
Digital Audio ◽  
Audio Compression ◽  
Typical Application ◽  
Production Program ◽  
Multichannel Audio ◽  
Digital Storage ◽  
The Status ◽  
Standardization Process

The Moving Pictures Expert Group within the International Organization of Standardization (ISO/MPEG) has developed, and is presently developing, a series of audiovisual standards. Its audio coding standard MPEG Phase 1 is the first international standard in the field of high quality digital audio compression and has been applied in many areas, both for consumer and professional audio. Typical application areas for digital audio are in the fields of audio production, program distribution and exchange, digital sound broadcasting, digital storage, and various multimedia applications. This paper will describe in some detail the main features of MPEG Phase 1 coders. As a logical further step in digital audio a multichannel audio standard MPEG Phase 2 is being standardized to provide an improved stereophonic image for audio-only applications including teleconferencing and for improved television systems. The status of this standardization process will be covered briefly.

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