Audio compression still unusable for movies


VRD6 beta 801a : Good to see that the Profile Editor's layout of audio normalization settings has been much improved. There is now a "Processing" selector, offering the choices "Normalize peak", "Dynamic leveling", or "Raise/lower level".

Despite the age-old problem of movie sources having rogue spikes and fluctuating audio levels, I look forward to being able to compress/normalize movie audio, as part of a self-contained movie transcoding profile in VRD6.

But we are not quite there yet. A reminder of the problems:-

"Normalize peak": not usable unless the movie is guaranteed to be free of any rogue spikes. To check this, the user would need a tool to inspect the audio envelope.

"Raise/lower level": might be useful if the movie is not spike-free, but the user would need a tool to examine the envelope and judge how much gain to apply.

"Dynamic leveling": the "compression" formerly advertised as a feature of VRD4 solved the problem well enough, but in VRD6 it no longer works for movies. I understand it's now tuned for voice; on movies it produces a severely distorted audio envelope. (See the illustration attached).

My own workaround is to use VRD4's dynamic levelling for the audio, VRD5/6 for the video, then mux them together with Yamb. Not really in the spirit of VRD6!

Picking up from the following thread,
could the solution be as simple as adding another option in the dialog, to switch to the V4 rolling/smoothing window time constants ?



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