Overview
IEC 61937-5:2006/AMD1:2019 is an important amendment to the IEC 61937-5 standard, issued by the International Electrotechnical Commission (IEC). It specifies the interface for non-linear PCM (Pulse Code Modulation) encoded audio bitstreams that comply with IEC 60958, focusing specifically on bitstream formats utilized by Digital Theater Systems (DTS). This amendment updates and refines the handling of DTS Type IV bitstreams, introducing new profiles and enhancing data burst control mechanisms for improved audio data transmission over digital audio interfaces.
Key Topics
- Non-linear PCM Bitstreams: The amendment deals with non-linear PCM audio data encoded according to DTS formats, enabling efficient digital transmission of compressed multi-channel audio signals.
- DTS Type IV Format: The update specifies parameters for DTS Type IV bitstreams, including:
- Burst repetition periods tied to IEC 60958 frame rates.
- Defined profiles (single burst mode and multi-burst mode) for flexible data transmission.
- Precise control of data bursts using multi-burst control bytes.
- Burst-Info Fields: New and modified Table 1 outlines fields representing repetition periods, data types, and profile indicators within data bursts for DTS encoded streams.
- Profiles of DTS Type IV:
- Profile 0 (Single Burst Mode): Delivers a DTS audio frame per burst with fixed, periodic transmission.
- Profile 1 (Multi-Burst Mode): Supports sequences of 1, 2, 4, or 8 bursts per audio frame, with detailed multi-burst control including burst indexing and delay factors to manage decoder latency.
- Decoder Latency: Clarifications on latency expectations in both single and multi-burst modes help system designers optimize synchronization and playback quality.
- Pause Data-Bursts: Recommendations on inserting pause data-bursts to effectively fill stream gaps, maintaining continuous playback without artifacts.
Applications
This IEC standard amendment is crucial for:
- Audio Equipment Manufacturers: Ensuring that devices such as digital audio players, receivers, and professional multimedia equipment correctly implement DTS non-linear PCM data streams over standardized IEC 60958 interfaces.
- Broadcast and Streaming Systems: Facilitating reliable transmission of DTS encoded multi-channel audio in environments where digital audio interfaces are used.
- Home Theater Systems: Enabling seamless integration and playback of DTS bitstreams over conventional digital audio connections, improving user experience with high-fidelity surround sound.
- Audio Codec Developers: Implementing precise timing, burst control, and error handling as specified, to ensure compatibility across devices.
- Digital Signal Processing: Leveraging the detailed burst and profile structures to optimize DTS audio stream decoding and latency management.
Related Standards
- IEC 60958: The fundamental digital audio interface standard that IEC 61937-5 builds upon for carrying non-linear PCM encoded bitstreams.
- IEC 61937 (Base Standard): Defines general principles for transmitting compressed audio data over IEC 60958 interfaces, including multiple bitstream formats beyond DTS.
- DTS Audio Format Specifications: Proprietary specifications by Digital Theater Systems, defining audio compression algorithms and frame structures referenced in this amendment.
- IEC TC 100: The technical committee responsible for audio, video, and multimedia system standardization, including development and maintenance of IEC 61937 and related standards.
By adopting the guidelines of IEC 61937-5:2006/AMD1:2019, organizations can ensure robust, interoperable handling of DTS non-linear PCM audio bitstreams within digital audio systems, enhancing performance and compatibility across a wide range of professional and consumer audio technologies.
Open preview (PDF)Amendment 1 - Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 5: Non-linear PCM bitstreams according to the DTS (Digital Theater Systems) format(s)
