Product Details

Dolby® Digital EX is an extension of the Dolby Digital decoding algorithm that adds a center rear channel to 5.1-channel playback, expanding the surround sound experience to 6.1 channels. The signal for the center rear channel is extracted from the left and right surround channels and can be sent to one or two speakers placed behind the listener. This module can only be shipped to pre-approved Dolby "qualified recipients."


  • API: C callable 'push'-type API
  • Highly optimised to run on the Analog Devices Blackfin processor family
  • Rigorously tested
  • Dolby Certified
  • The module contains a standard C-callable ‘push‘ API with the added flexibility of using ‘pull’ (or ‘poll’) by adding light ‘wrapper’ code. The module has no dependencies on processor peripherals or registers, adding greater system flexibility and ease
  • Conformance Standard: 'Dolby Digital EX', Provisional Draft Version 1.01, ATSC Standard A/52 - 1995 + Annex D, Digital Audio Compression (AC-3)
  • Conformance Standard: Dolby Digital Decoder Implementations Test Procedure, Issue 2, “Dolby Pro Logic IIx Implementation Test Procedure”, Issue 1, 2003
  • Reference Code Revision: Dolby Digital Decoder C Source Code version 7.1.0; Dolby Pro Logic IIx Decoder Simulation Version 2.00
  • Target Processor: BF537, code compatible across the Blackfin processor family ADSP-BF5xx
  • Framework dependencies: None- No dependencies on processor peripherals or registers
  • Release format: Object code module with C source wrapper
  • Input format: Raw AC-3 bit stream
  • Output format: PCM, 32 bits per sample, non interleaved, 6 or 7 channels corresponding to 5.1 or 6.1 speaker configurations
  • Output buffer samples per block: 256
  • Sample Rate: All sample frequencies specified by the AC-3 standard – 32, 44.1 and 48 kHz
  • Bit Rate: All bit rates specified by the AC-3 standard: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 448, 512, 576 and 640 kbps
  • Multi-channel: Fully re-entrant and multi-instancing capable

System Requirements

  • Windows XP Professional SP3 (32-bit only).
  • Windows Vista Business/Enterprise/Ultimate SP2 (32-bit only). It is recommended to install the software in a non-UAC-protected location.
  • Windows 7 Professional/Enterprise/Ultimate (32 and 64-bit). It is recommended to install the software in a non-UAC-protected location.
  • Minimum of 2 GHz single core processor, 3.3 GHz dual core is recommended.
  • Minimum of 1 GB memory (RAM), 4 GB is recommended.
  • Minimum of 2 GB hard disk (HDD) space is required.

Related Hardware

Performance Metrics

MIPS summary:

Code memory (KiB) Data RAM (KiB) Constant Data Tables (KiB) MIPS
Average Peak
38.0 39.2 15.0 113.8 127.1

  • This table highlights example Blackfin processors and expected MIPS performance.
  • Some processors include additional L2 internal memory (e.g. BF548) which can help reduce MIPS when fully utilized.
  • Similarly, processors with high speed external memory interfaces (32-bit versus 16-bit or DDR versus SDRAM) will also help reduce overall MIPS requirements.
  • In the table above, all figures refer to one instance of DDEX. "Data RAM" includes Stack, Scratch, Instance State, one single-buffered input buffer and seven single-buffered output buffers, each containing 256 32-bit samples.
  • MIPS figures indicated in the table have been measured using 48 kHz sampling frequency, 7 output channels (6.1 speaker configuration), optimal memory layout, worst-case input test vectors, and a block size of 256 samples per channel.
  • Heap (or "malloc()") is not used.
  • 1 KiB = 1024 Bytes.

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Availability and Licensing

Each module supports the Analog Devices, Inc. (ADI) Blackfin or SHARC Processor family and is a licensed product that is available in object code format. Recipients must sign or accept a license agreement with ADI prior to being shipped or downloading the modules identified in the license agreement.

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