Determine the RMS and peak dB of the SurroundInvert file.Mix the CenterInvert file into the Surround file at 0 dB (both CenterInvert and Surround should be mono).Invert the Center file into a new file.You'll have to experiment with several DPL2 and non-DPL2 sources to see what these tolerances are, but after a dozen or so files the numbers should become clear. If the RMS or peak DB of the Surround file are below "a tolerance", stop the original file is either mono or center-panned and hence contains no surround information.Determine the RMS and peak dB of the Surround file.Mix down the Left and RightInvert channels to a new mono file at -3dB per channel.Split the left and right channels of Input into separate files.
Mix down the Input stereo channels to a new mono file at -3dB per channel.Crop the first N seconds or so of program content into a stereo file, where N is between one and thirty.I'll sketch out for you a method that might work, and I'll try to express it without writing code, but it's up to you to implement and refine it to your liking.
So the trick is to detect whether important data is being stored in the surround channel(s). This is either done trivially, as in Dolby Surround, or else these similarities are artificially biased to be pushed much further to the left or right, or the left or right surround, as in DPL2. Dolby Surround type decoders, including DPL2, attempt to recover this information by inverting the phase of one of the two channels and then looking for similarities in these signal pairs.
Dolby advanced audio v2 error pro#
Tl:dr it's probably possible it may be easier if you're a programmer.īecause the information encoded is just a stereo analog pair, there is no guaranteed way of detecting a Dolby Pro Logic II (DPL2) signal therein, unless you specifically store your own metadata saying "this is a DPL2 file." But you can probably make a pretty good guess.Īll of the old analog Dolby Surround formats, including DPL2, store surround information in two channels by inverting the phase of the surround or surrounds and then mixing them into the original left and right channels.