Miranda Technologies’ Michel Proulx, CTO spent most of his press conference time discussing the problems broadcasters face in delivering good new 5.1 audio. "Time and time again, we’ve found that it’s multi-channel audio that causes the most problems when transitioning to HD," he said.
He described three key problem areas: loudness measurement and control; handling Dolby metadata; and maintaining 5.1 surround sound when playing out stereo legacy content. He said that loudness control is especially evident to anyone watching popular HD programming.
Miranda’s new solutions for these issues include new Densité Series cards with advanced audio processing, upmixing and level control. The DAP-1781 audio processing module. The DAP-1781 is an eight channel digital audio processor which can perform accurate loudness control and measurement, using ITU-R BS.1770 or LEQ(A) and trigger an alarm if limits are exceeded.
The DAP-1781 can also perform high quality Dolby E and /or AC-3 decoding and encoding directly on the card. By pairing two DAP cards to a video processor, it is possible to perform both decode and re-encode in a single functional block.
The DAP processor can also provide a high quality stereo to 5.1 upmix using Linear Acoustic’s upMAX technology. The processor creates an infinitely adjustable, multi-channel signal that is down-mix compatible. This makes it ideal for converting legacy two-channel audio content into 5.1 programs.
Related article: Miranda adds 5.1 audio processing for HD broadcasters.