[mythtv-users] what is the order of preference of LPCM, DD, and DTS

[Jean-Yves Avenard]

Hi

On 18 November 2010 01:24, Brian J. Murrell <brian at interlinx.bc.ca> wrote:
> More questions about the new audio configuration settings...
>
> In 0.24, if I have all of LPCM, DD, and DTS selected, what is the
> preferred output method?  Is it decoding by Myth and sending as PCM or
> is it passing through of DD and DTS?  In my experiments, it appears that
> passthrough is preferred if DD (or DTS) are selected, even if LPCM is
> selected.

if the audio can be pass through, it will be, that is AC3 or DTS

if audio needs to be processed in any ways, requiring the decoding by
myth of either the AC3 or DTS stream ; then if LPCM is available, it
won't re-encoded to AC3

E-AC3, TrueHD has to be decoded.

>
> I guess with such selected options, LPCM is used as a fallback, when
> audio is not encoded with AC3/DTS.  But wouldn't LPCM always be the fall
> back for a digital connection anyway?  I guess I'm failing to understand
> why LPCM is even an [un]selectable option if it chosen as a lower
> priority to DD/DTS passthrough when all three are selected anyway.

AC3 and DTS can't only do 16 bits, 5.1 audio.

LPCM can do up to 7.1 at much higher resolution.
so LPCM does have its use