應科院ARM9E
3GPP AMR-NB 語音解碼器(暫時只提供英文版本) |
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Processor
ARM ARM9E family and above with DSP extensions
Background
3GPP Adaptive Multi-Rate Narrow Band (AMR-NB) recommendation
compresses linear-PCM (Pulse Code Modulated) speech input
data, at a sample rate of 8kHz, to one of eight data rate
modes 12 200, 10 200, 7 950, 7 400, 6 700, 5 900, 5 500
and 4 750 bps. The data rate can be run-time selectable
by the user.
AMR-NB
implements silence compression techniques to reduce the
transmitted bit rate during silent intervals. Systems allowing
discontinuous transmission (DTX) are based on Voice Activity
Detection (VAD) algorithms and Comfort Noise Generator (CNG)
algorithms that allow the insertion of Silence Insertion
Descriptor (SID) frames during the silence intervals. There
are two VAD options at the encoder. |
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Full
conformance to 3G TS 26.074 V 6.0.0 (2004-12) including
VAD1 and VAD2 |
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Supported
sampling frequencies (Hz): 8K |
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Bitrate
scalability per channel: 12 200, 10 200, 7 950, 7 400,
6 700, 5 900, 5 500 and 4 750 bps |
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Provides
mono decoding |
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| ASTRI
Specific Features |
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Provides
multiple-decoder instance |
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Provides information on AMR-NB bitstream after each
successful decoding frame |
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Provides
infra-structure for conformance testing |
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Provides API for streaming application |
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Accepts
raw 3GPP stream from MPEG-4 audio container |
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OS
compatibility: Embedded Linux (Monta Vista, Candenux),
Non-OS, ARM RealView |
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Memory
requirements: 208KByte (Program and Data) |
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| Performance |
| ASTRI
ARM9E 3GPP AMR-NB decoder is optimized for the ARM9E architecture.
The performance is depended on several factors of the target
ARM9E platform: |
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I-Cache
size |
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D-Cache
size |
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SDRAM
speed |
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Availability of TCM |
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| Please
make enquires on the performance for a specific ARM9E platform. |
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