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MediaArea / MediaInfo

Convenient unified display of the most relevant technical and tag data for video and audio files.
https://MediaArea.net/MediaInfo
BSD 2-Clause "Simplified" License
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Dolby Digital EX detection #472

Open Krobar opened 3 years ago

Krobar commented 3 years ago

Any chance detection of the Dolby Digital EX flag could be added? (DTS ES Matrix detection seems to be implemented)

JeromeMartinez commented 3 years ago

@Krobar a sample file please.

Krobar commented 3 years ago

Hi @JeromeMartinez

Sorry I've been so slow to respond. First 100 frames attached (Rename to MKV) DDEX.log

JeromeMartinez commented 3 years ago

Sorry I've been so slow to respond.

I am not faster :)

First 100 frames attached

From specs (look for dsurexmod), bitstreams with bsid of 8 (and this is the case for your file) can not provide information about EX. The encoder should have switched to bsid of 6 for being able to provide EX info (which is not mandatory).

So impossible to detect the EX without decoding the AC-3 stream and catching the hidden EX bitstream from it. Not in the scope of MediaInfo (which relies on metadata or in worst case scenario in the encoded bistream, without decoding).

JeromeMartinez commented 3 years ago

@Krobar I found a couple of E-AC-3 files with EX flag + one (and only one!) AC-3 file with EX flag. Was enough for my tests though.

--> I'll support the EX flag detection, but EX line display in MediaInfo will be there only if the stream has the corresponding (non mandatory) flag. You file may be EX, just that it is not flagged as such (and the flag has no impact on the decoding, and the EX is "encoded" in the decoded content, and it is sure that I won't implement the AC-3 decoding not the maths for the matrix detection in MediaInfo, too much).

Krobar commented 3 years ago

Thank you. I was just about to say I found a file which MKVToolNix knows is DDEX which I suspect is the same thing.