Overview
ISO/IEC 13818-7:2006 specifies MPEG‑2 Advanced Audio Coding (MPEG‑2 AAC or AAC), a multichannel audio coding standard designed to deliver higher audio quality than MPEG‑1 when backward compatibility is not required. The standard defines bitstream formats, decoder tools, profiles and interoperability rules. It targets high‑quality multichannel audio - providing ITU‑R “indistinguishable” quality at about 320 kbit/s for five full‑bandwidth channels - and documents how to combine MPEG‑2 AAC with Spectral Band Replication (SBR) from ISO/IEC 14496‑3.
Key Topics
- Bitstream formats and syntax: Audio Data Interchange Format (ADIF), Audio Data Transport Stream (ADTS), and raw data structures.
- Decoder tools (required vs optional): lists required functions (bitstream formatter, noiseless decoding, inverse quantization, rescaling, filterbank/block switching) and optional tools (M/S, prediction, intensity stereo, coupling, TNS, gain control).
- Profiles & interoperability: profile definitions and rules to ensure compatibility between encoders and decoders.
- Core coding modules: noiseless coding, quantization, scalefactors, joint coding (M/S, intensity), prediction, Temporal Noise Shaping (TNS), filterbank and block switching, gain control.
- Program configuration and channel elements: Single Channel Element (SCE), Channel Pair Element (CPE), Low Frequency Enhancement (LFE), Program Config Element (PCE), Data Stream Element (DSE).
- Supplementary guidance: how to utilize SBR (bandwidth extension) from ISO/IEC 14496‑3 together with MPEG‑2 AAC.
- Implementation notes: normative tables (e.g., Huffman codebooks), informative annexes on encoders, patents and registration procedures.
Applications
- Audio codec implementers: encoder and decoder developers building compliant MPEG‑2 AAC products.
- Broadcast & streaming: multichannel audio for digital TV, satellite, and streaming services requiring efficient high‑quality audio.
- Consumer electronics: set‑top boxes, AV receivers, portable players and mobile devices implementing AAC decoding.
- Multimedia software: media players, authoring tools and transcoders that need interoperable AAC bitstreams.
- Standards & testing labs: conformance testing, interoperability verification, and codec certification.
Related Standards
- ISO/IEC 13818 (MPEG‑2) family - Parts 1–6, 9–11 define systems, video and related extensions.
- ISO/IEC 14496‑3 (MPEG‑4 AAC / SBR) - referenced for Spectral Band Replication (SBR) integration.
Note: ISO/IEC documents may reference patented technologies; implementers should verify licensing obligations (Annex D contains patent holder information).
Keywords: ISO/IEC 13818-7:2006, MPEG-2 AAC, Advanced Audio Coding, multichannel audio coding, ADIF, ADTS, SBR, ISO/IEC 14496-3, AAC profiles, audio codec standard.