Dolby AC-3 Encoder and Decoder

Dolby Digital™ (AC-3) is a perceptual audio coding standard for high quality multi-channel audio at low bit-rates with support for consumer features such as volume normalization and dynamics processing. Ittiam’s AC-3 Decoder is an implementation of Dolby Digital Consumer Decoder (DDCD) capable of delivering up to 5.1 channels and the encoder is an implementation of Dolby Digital Consumer Encoder (DDCE) capable of delivering up to 2 channels.

Dolby AC-3 Decoder Technical Specification

• 5.1 Channel decoding
• Sampling Rates 32, 44.1 and 48 kHz
• Bit-rates of 32-640 kbps
• Channel Coupling
• Rematrixing
• Dialog normalization
• Dynamic Range Compression
• Downmixing
• Error detection (CRC checking)
• Supports Annex C of ATSC-A52 (Karaoke Capable)
• Supports Annex D of ATSC-A52 (Extended bitstream)
• Implementation fully compliant to the DDCD (Dolby Digital Consumer Decoder) specification and certified
• Supports a simple C callable with flexible memory allocation scheme
• Multi-channel, reentrant software
• Optimized for low footprint and processing power

Dolby AC-3 Encoder Technical Specification

• Stereo (upto 2) channel encoding
• Sampling Rates 32, 44.1 and 48 kHz
• Bit-rates of 64-640 kbps
• Rematrixing
• Dialog normalization
• Dynamic Range Compression
• Implementation fully compliant to the DDCE (Dolby Digital Consumer Encoder) specification
• Tested on a variety of bitstreams and audio files for robustness and quality
• Multi-channel, reentrant software
• Optimized for low footprint and processing power

Applications

• DVD Players
• Gaming Console
• DVD Audio
• Portable Media Players
• DVD-RW
• Digital Video Broadcasting
• Digital TV

Platforms

• Decoder currently supported on ARM (ARM9E™), TI DM320™, TI C64x™ (TMS320C64x™)
• Planned support for decoder on ARM11™, TI C64x+™/DaVinci™ (DM644x™)
• Planned support for encoder on TI C64x+™/DaVinci™ (DM644x™)
• For further details contact mkt@ittiam.com