Hi - I'm posting here because I'm not sure if this is a Kodi issue or a skin creation issue.
I came across a post on the forum about 6 months ago regarding a skin or skins - and how they always display either just "Dolby" or "TrueHD" whether the stream is also Atmos or not.
The response was that FFMpeg doesn't parse Atmos or DTS:X yet - we'd have to wait on an update...and I didn't ever really investigate - until I saw that FFMpeg 4.0 was just released.
What I found had nothing to do with the new release:
Is there something I'm missing here?
Yes you are missing something.
An Atmos stream consists of a TrueHD lossless audio plus an extension that provides the object data. The extension part used a framework defined in the TrueHD spec that had never been previously used, this is why many existing devices can pass Atmos without needing to be updated, however ffmpeg didn’t take into account an extension can exist, thus when it saw an Atmos stream it didn’t jnow what to do with it, hence the readable comment in what you link. So what happened is the parser was updated so ffmpeg could see there was a TrueHD plus extension audio stream, this allows ffmpeg to read the TrueHD part in order to be able to decode the TrueHD part, and the extension part is effectively discarded. As there is no opensource Atmos decoder available there’s no way to know if anything is contained in the extension part if it exists, so there’s no way for ffmpeg to identify if it’s a valid Atmos stream.
OK - I figured if there was a way to do it, the skin creators would have taken advantage of it, but that "fixed/closed" status gave me pause. Basically, FFMpeg had trouble reading THD+A streams and they "fixed" TrueHD, if I read you correctly.
Btw, I read the bullet point items on FFMpeg 4.0, but didn't see anything about the object-based audio formats. Do you happen to know - is it not important enough to be amongst the major new features, or perhaps Dolby and/or DTS aren't ready to allow open source software implementation yet?
(I believe the other codec decoders are free for distribution as part of non-profit / open source projects, and that's how all this works...could be wrong.)
Being free open source software we can not pay to belong to the relevant associations and to access the relevant specifications from Dolby/DTS, we totally rely on ffmpeg implementing this stuff, and since they are also free open source they generally rely on someone backward engineering formats or the specifications being leaked.
Right - I assume that TrueHD and DTS-HD Master Audio were not available via ffmpeg right away either. I just wonder how long it took them to become available to ffmpeg for that capacity.
Not likely to be exactly the same anyhow - I will just have to keep modifying my skin to look for Atmos / DTS-X in the filename. Kind of a pain in the butt when the skin updates, etc... but its all good.