MPEG-4 AAC-LD Encoder and Decoder
Advanced
Audio Decoder 
C64x, C64x+
MPEG-4 Low Delay Advanced Audio Coding (AAC-LD)
The MPEG-4 Low Delay Audio Coder is designed to combine the advantages of perceptual audio coding with the low delay necessary for two-way communication. It has achieved wide acceptance in high end video conference terminals and is used in professional broadcasting applications. The codec is closely derived from MPEG-4 Advanced Audio Coding (AAC-LC). It features an algorithmic delay of only 20 ms while offering good compression ratios and high sound quality audio quality for all kinds of audio signals including speech, music and atmospheric sounds. This way, AAC-LD bridges the gap between speech coding schemes and high quality audio coding schemes. Unlike common speech coders, the achieved coding quality scales up with bitrate, and transparent quality can be achieved.
Platforms
Currently supported on TI C64x™ (TMS320C64x™), TI C64x+™/DaVinci™ (DM644x™)
Features
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Suitable for all kinds of audio signals including speech and music
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Audio quality better than ITU-T G.722/G.722.1-C, G.729.1 at the same bit rate
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Audio quality better than mp3 at the same bit rate
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Algorithmic delay of only 20 ms
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Delay of real-time DSP implementation down to 30 ms
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Multi-channel support
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Large range of bit rates possible
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Computational and storage complexity comparable to MPEG-4 AAC-LC
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Error resilient AAC-LD audio object type
Specifications
C64x
All Memory usage is given in units of byte.
Function |
MIPS* |
Program Memory |
Data Memory |
Per-Channel Data Memory |
Encode |
31 |
103 k |
50 k |
30 k |
Decode |
13 |
71 k |
18 k |
30 k |
C64x +
All Memory usage is given in units of byte.
Function |
MIPS* |
Program Memory |
Data Memory |
Per-Channel Data Memory |
Encode |
29.5 |
98 k |
50 k |
30 k |
Decode |
12.4 | 67.5 k |
18 k |
30 k |
Applications
