[mythtv] Ticket #7426: Static noise from 96kHz/24bit audio files in MythMusic

Jean-Yves Avenard jyavenard at gmail.com
Sat Nov 14 18:01:22 UTC 2009


Hi

2009/11/15 Warpme <warpme at o2.pl>:
> Well,
>
> Let me point out that from my perspective, message passed by my report is no
> "me too" but rather info that it is regression.

MythMusic doesn't handle any non-16 bits audio and never did...

The patch in the ticket adds automatic conversion of any non-16 bits
audio to 16-bits audio. It was deemed that performing the 24/32 -> 16
bits conversion in mythmusic itself wasn't the way to do it, and
instead the audio class should either natively support those audio
format, or perform the conversion.

Those changes will be committed when I'm done ; in the mean time, use
the patch if you need this functionality now.


>
> Maybe I wrongly interpreting comments of jyavenard (as for me it suggest
> that issue is result of limitations of mythtv/spdif).

it isn't an issue with spdif, it's an issue with mymusic.

It assumes that all content is 16 bits and initialise the audio class
to receive 16 bits audio.
It's always been that way.

> Also nature of proposed solution is more workaround than RCA with final
> solution not decreasing myth functional level.

If you want to provide a patch that implements native 24/32 bits audio
support ; feel free to open a new ticket and submit it...

>
> As in past all was OK, if I would be developer  - my msg will be key for me,
> as it change interpretation of issue from "it is design limitation" to "it
> is regression"

If it ever worked, it would have been a pure coincidence.(FFmpeg has
added 24/32 bits audio support across most codec, so where it would
have done down-conversion now it passes it through which myth doesn't
handle)

>
> By above I disagree with Your kind remark about useless nature of my
> report....

You have to admit it wasn't the most useful report to start with.
I certainly disagree with Robert that this discussion has no place in
the list. Where else would be a write place if it's not on the list??

>
> If You can't/don't have willingness/time/whatever to help resolve it - fine.
> I really appreciate Your work on myth.

native 24/32 bits audio support is on the way...
But it's no simple task because there are so many audio systems out
there (alsa, oss, oss3, mac, win, dx, you name it)..

So the solution I'm implementing will expande the audio class to
support > 16 bits audio , starting with alsa ; with other sound system
it will be by default down-converted to 16 bits audio.

Jean-Yves


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