[FFmpeg-user] How can I convert mpeg2 5.1 audio to ac3?

[Moritz Barsnick]

On Tue, Nov 11, 2014 at 07:11:33 -0600, Mike Brown wrote:
> That doesn't make any sense.  AC3 5.1 is usually done at 384 kbps, while
> AC3 2.0 is 192 kbps.  The 192 kbps difference is a drop in the bucket
> compared to all of the other packets that make up the transponder mux.

I think you're right - I was (stupidly) trying to make sense of it. All
I do know, e.g.: The "major" channel "RTL" uses various audio stream
types in its programming on the SD channel, depending on the type of
show and the material. The minor channels, such as "RTL2" only ever
have one MP2 audio and one AC-3 audio stream, with two channels each.
For whatever reason. (We might need to use other examples than these
two channels, but I'm speaking or "relatives" in a family of channels.)

BTW, the major (SD) channels also get much more overall bandwidth than
the minor ones, resulting in very sharp video quality (or rather quite
sucky video quality on the latter channels). I don't know exact
numbers, but I believe there may be more than a 2x factor. Audio is
probably still said drop in the ocean.

Moritz