IMA ADPCM is a 4-bit Adaptive Differential Pulse Code Modulation (ADPCM) algorithm standardized by the Interactive Multimedia Association (IMA). The codec operates on each 16-bit audio sample and generates a 4-bit ADPCM sample. The ADPCM algorithm is a waveform coding technique which predicts the current signal value from the previous values and transmits only the difference between the real and predicted value. The codec is widely deployed in Windows and Macintosh operating systems.
- Based on IMA ADPCM open standard.
- Fixed-point ANSI C implementation.
- Re-entrant implementation
- C-callable APIs
- Operates on 16-bit input audio signals sampled at 8, 11.025, 22.05, or 44.1 KHz.
- Bit-compliant with Microsoft Sound Recorder Application.
- Support for mono and stereo channel modes.
- Optional support for xDM APIs
- Validated on TI DM6446 EVM platform.
- Tested for compliance using a large database of audio test vectors
- Tested for multi-instance implementation
- Tested for various input block sizes
- Tested for mono and stereo test vectors.
- Tested for graceful exit in case of bit-stream related errors or exception.
- Tested with scratch contamination at frame boundaries.
- Range validation for all API parameters.
- Tested for 100% code-coverage
ARM9E, ARM11, Cortex-A8, Cortex-A9, TI C55x, and TI C64x+.