Windows Media Audio Standard (WMA STD) was first introduced by Microsoft in the year 1999. It operates on 16-bit audio signals, mono or 2-channel stereo, sampled at 8-48 KHz and generates compressed bit-streams having bit-rates in the range of 5 – 384 kbps. The compressed bit-stream is represented by the Advanced Streaming Format (ASF) which packetizes the payloads and frames. ASF format makes it suitable for streaming and portable applications. WMA STD is a transform domain codec and is based on the modified discrete cosine transform. It has three profiles L1, L2, and L3. L1 supports only 44.1 KHz sampling frequency, up to 160 kbps bit-rate and is intended for constrained audio-only devices. L2 includes L1 and supports up to 48 KHz sampling frequency and bit-rates up to 256 kbps. L3 includes L2 and supports bit-rates up to 384 kbps. It is one of the most popular audio codecs and has been extensively deployed in portable media players, mobile phones, as well as network connected devices. WMA STD is Microsoft's proprietary audio codec subjected to terms and conditions of Microsoft License agreement.
Salient Features:
1. Based on Windows media porting kit (WMPK) version 10 provided by Microsoft.
2. Optimized ASM/C implementation.
3. Re-entrant implementation
4. C-callable APIs
5. Supports sampling frequencies ranging from 8KHz to 48KHz.
6. Supports forcing the output to 16-bit and 24-bit PCM.
7. Supports bitrates ranging from 5 kbps to 384 kbps.
8. Supports for mono and stereo (2 channel) output.
9. Support for content encoded with WMA v4.0 encoder
10. Supports ASF container format as part of WMA decoder library.
11. Supports downmixing to mono output.
12. Supports Interleaved and de-interleaved output.
13. Supports MBR (Multi Bit Rate) streams and can select the required bit-rate at the init-time.
14. Decodes the audio content in WMV streams.
15. Implementation certified by Microsoft.
16. Optional support for xDM APIs.
17. ARM implementation is validated on OMAP3530 (Cortex-A8) and DM6446/DM6467 (ARM926EJ-S) platforms.
Resource requirements (ARM9E -- flat memory):
-- MCPS = 20
For most current information on the performance specifications and availability of developed implementation on ARM cores, please send in your enquiry to info@couthit.com