WMA VCE, WMA Voice

CODEC OVERVIEW

Windows Media Voice (WMA VCE) is a low bit-rate codec designed by Microsoft to compress speech signals. The codec uses Codebook-Excited Linear Prediction (CELP), wherein the method of linear prediction in conjunction with analysis-by-synthesis technique is used coding. Optionally, the codec also supports music signal where it uses the low bit-rate WMA Standard. WMA VCE supports four sampling rates 8 khz, 11.025khz, 16khz and 22.05 khz and bit rates ranging from 4kbps to 20kbps and can accept only mono streams. WMA VCE content is packed using the ASF container format. Windows Media Voice is used in streaming compressed voice over the Internet for radio and is also used in voice recorders and in low bit-rate streaming applications.

SALIENT FEATURES
  • Based on Windows media porting kit (WMPK) version 9 provided by Microsoft.
  • Optimized C implementation.
  • Re-entrant implementation.
  • C-callable APIs.
  • Supports sampling frequencies 8KHz, 11.025KHz, 16KHz and 22.05KHz.
  • Supports bit-rates ranging from 4kbps to 20kbps.
  • Supports decoding of ASF content.
  • Optional support for xDM APIs on TI platforms.
TESTING FEATURES
  • Tested for bit-exactness with standard as well as a large database of non-standard test vectors.
  • Tested for graceful exit in case of bit-stream related errors or exception.
  • Module is fully interruptible
  • Tested for Input buffer corruption.
  • Tested for I/O buffer alignment requirements.
  • Tested for multi-instance implementation.
  • Tested for 100% code coverage.
  • Range validation for all the API parameters.
  • Tested with scratch contamination at frame boundaries.
  • ARM implementation validated on OMAP3530 (Cortex-A8) and DM6446/DM6467 (ARM926EJ-S) platforms.
AVAILABLE PLATFORM(S)

ARM9E, ARM11, Cortex-A8, and Cortex-A9.

For resource requirements & other details