.wav files with DTS content return wrong number of channels

[jcelerier]

Ex. : the following DTS test file is 6 channels (ffmpeg finds them) but dr_wav only finds 2. I think that if the format cannot be read (which is absolutely fine, it's not dr_wav's goal to decode dts) then the init functions should return false and set values to zero so that the calling app can either warn the user or use another decoding method (in my case I use dr_wav for fast WAV mmap'ing and fallback to full libavcodec for more complex file formats for instance).

But here the whole of drwav_init__internal passes and drwav_init_memory_ex returns true so there's not really a way to know it's not supported until it's too late if the user loads such af ile.

DTS 5.1.wav

[mackron]

Thanks. I'm not entirely sure how to handle this one because from the perspective of dr_wav the attached file looks exactly like a regular PCM stream. By that I mean the format is set to 0x1 which is PCM (Microsoft documents the DTS format as 0x8 - https://learn.microsoft.com/en-us/windows/win32/medfound/audio-subtype-guids). Even the header is a regular old WAV header and not the extensible one so I can even look at a sub-type. So from what I can tell, the only way to check if it's a DTS stream would be to inspect the data from the "data" chunk and check the first 4 bytes for a DTS sync code? I was kind of hoping to avoid having to do that just to keep the code simple. Regardless, I think I'd need some advice on how to properly detect a DTS stream. I have no experience with it.

Will sit on this and consider. Advice welcome on how to handle it!

[jcelerier]

So from what I can tell, the only way to check if it's a DTS stream would be to inspect the data from the "data" chunk and check the first 4 bytes for a DTS sync code?

that's the only way I could find too :/ that's a pretty sad overloading of file format ; my understanding is that it's this way so that hardware audio players can just passthrough the wav file believing it's normal PCM to something else in the chain that will recognize the DTS sync code and decode it as DTS

[jcelerier]

Some google discussion : google/ExoPlayer#3340