Linear Acoustic, a leading innovator of solutions for distributing and processing multichannel sound, has unveiled a remarkable new system that dramatically simplifies the monitoring of essential audio metadata parameters within digital signals being carried between network centers, and delivered to consumer playback systems.
"For the first time," offers Linear Acoustic president Tim Carroll, "the new Model LA-5170 Audio Metadata Analysis System - AMAS - provides a clear 'Go/No-go' indication of metadata parameters and, through logging, allows unattended checking of entire programs."
Software controls enable the setting of limits for critical parameters; any variance from these will be displayed and logged. Errors are also displayed for parameters that can interact inappropriately if set incorrectly.
Audio Metadata - also known as Dolby Metadata - has the capability of managing critical aspects of audio for digital television and DVD uses. Used correctly, metadata can help guide reproduction of audio to match the producer's original intent, but faulty or incorrect values can produce the exact opposite.
Audio Metadata contains some 30 parameters for each program being carried. "While some metadata values only serve an informational purpose," Carroll explains, "several can directly affect audio playback. If set correctly, parameters such as dialog level, audio coding mode, dynamic range control and down mixing can combine to produce high quality soundtracks. But the parameters can also combine to create unacceptable audio loudness shifts, loss of dialogue or inappropriate dynamic range."
Information is also provided for distribution-audio coding systems such as Dolby E. Correct guard band position is extremely important for this system, since it directly impacts its ability to be edited or switched. The LA-5170 compares incoming Dolby E frame position to the video reference input and displays the result.
A custom Windows®-compatible application that connects to AMAS over Ethernet via TCP/IP provides extensive display of metadata, Dolby E guard band, video reference and linear time code (LTC) parameters. Individual errors are highlighted by Red/Amber/Green indicators while a summary alarm alerts operators to problems that require closer inspection. A log file is created that shows errors time stamped with current PC time and incoming LTC time.
A bright LED display, rotary encoder, and four control keys provide for straightforward menu navigation and function adjustment on the local interface unit.
A rear-panel 9-pin D-sub connector carries metadata input/output signals per SMPTE 207M (RS-485) and is designed to interface with Dolby Metadata and LM100 protocols. The Model LA-5170 occupies 1U of rack space, and weighs just six pounds.