|Title:||Implementation of speech coding technique in MPEG/audio coding|
|Subject:||Speech processing systems|
Hong Kong Polytechnic University -- Dissertations
Department of Electronic and Information Engineering
|Pages:||51 leaves : ill. ; 30 cm|
|Abstract:||In multimedia applications such as video transmission and storage, the ISO standard MPEG/audio has been used extensively. This algorithm was developed by the Motion Picture Experts Group (MPEG), as an ISO standard for the high fidelity compression of digital audio. Unlike vocal-tract-model coders specially tuned for speech signals, the MPEG/audio coder gets its compression without making assumptions about the nature of the audio source. Instead, the coder exploits the perceptual limitations of the human ear. Much of the compression results from the removal of perceptually irrelevant limitations of the audio signal. Removal of such parts results in inaudible distortions, thus MPEG/audio can compress any signal meant to be heard by human ear. In addition, for different level of resulting quality, the compressed bitstream can have one of several predefined fixed bit rates ranging from 32 to 192 kbit/sec per channel. While the coding quality of MPEG/audio is satisfactory, there is room to further reduce the bit rate of compressed signal. CELP-based approach has been very successful in telephone bandwidth speech coding, but is not suitable for coding non-speech signals because of the assumed signal production model. Low-delay Code-excited Linear Prediction (LD-CELP) is ITU/CCITT standard G.728 which is a 16 kbit/sec low-delay speech coder. It can achieve a high speech quality better than G.721 with a one-way coding delay less than 2ms. In this project, an approach is proposed to mixed speech/music coding, which uses a discriminator to separate music signals from speech, and codes them with the MPEG/audio coder and a LD-CELP speech coder, respectively. In testing for different audio clips, the system shows promising results.|
|Rights:||All rights reserved|
Files in This Item:
|b1517721x.pdf||For All Users (off-campus access for PolyU Staff & Students only)||1.98 MB||Adobe PDF||View/Open|
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item: