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Old 13th June 2019, 23:17   #14841  |  Link
thecoreyburton
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I often use eac3to to demux BD streams. In the past I've noted a common delay of just above 21ms (there's a remaining delay of less than 1ms) when dealing with DTSHD track transcoding (eg. DTSHD > FLAC). At the time, I read up on this a fair bit and did some of my own testing, eventually concluding that a simple "-21ms" parameter would be ideal when dealing with DTSHD in this way.

There's plenty of discussion about this, but a lot of it seems related to specific issues and I can't find anything conclusive about whether or not this is the right way to approach this. I'm not sure if there is a "correct" way to do this (for instance a trim based on samples / frames to make it align perfectly or some internal function that does this), or if I should be touch this value at all. I believe it's an encoder delay (and not a decoder delay, but I could be wrong) and so it stands to reason that if this is true, perhaps some BDs have been authored with compensation for this delay in mind.

I was wondering if the way I'm handling it is the correct procedure, or is there a better way?
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Old 14th June 2019, 02:33   #14842  |  Link
tebasuna51
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It is know than encoders add initial silence samples to initialize some encoders buffers, for instance if you recode to AC3 you obtain a delay of 5 ms, until 38 ms with some AAC encoders.

But with some encoders that delay is stored in metadata and any decoder must restore the audio without delay. For instance AAC in mp4 container (.m4a) must play without delay.
I can't reproduce the problem recoding DTSHD to FLAC, for me the obtained .flac is decoded without delay.
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