[FFmpeg-user] How to convert music into DTS encoded WAV file?

Moritz Barsnick barsnick at gmx.net
Wed Aug 10 21:05:38 EEST 2016


On Wed, Aug 10, 2016 at 19:31:28 +0200, Peter White wrote:
> That does not make much sense, since the final file is supposed to be
> fltp, which is 32 bit, anyway.

This may be a misconception. I believe the "fltp" ffmpeg prints for its
inputs is the format the decoder presents. I didn't find any indication
that DTS encodes with floating point. Actually, it should be 14 or 16
bits, or up to 24 for DTS-HD. That certain "other tool" identified
these as 20 bit, which leads me to believe it's DTS-HD. I'm not sure
about the state of things, but in 2013, ffmpeg only decoded the core of
DTS-HD.

> But another thing popped into my head. Since it is a 6-channel audio,
> the bitrate should be more than 1411k. This looks an awful lot like a
> stereo bitrate, which would actually be 1411.2k (16*44.1k*2).

It's compressed, and standard DTS is lossy. Your calculation is only
valid for uncompressed PCM.

> Is it possible that this is a matrix encoding, like Dolby Prologic? I
> don't know if it matters at all but I think it's worth pointing out,
> just in case.

If is was matrix encoded (into 2 channels), ffmpeg's demuxer would only
show you 2 channels. Matrix decoding 2->X.1 is done in audio filters,
IIRC.

I'm still confused at to what this file really is. ;-)

Moritz


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