Previously an argument could incorrectly get split up even though it
was passed as one argument to the configure.sh wrapper script.

No need to prepare a picture if the chroma is bogus.
And mark the unlikeliness of the chroma being bogus.

It's done in picture_Setup().

It's done in picture_NewPrivate() but not here. So it ends up lost.

Ref: #21192

There's no way to tell lavc where to crop the video so we copy the metadata
from the decoder source format.

Ref: #21192

Following 60fb9f2b
Init to 20ms since 0 will be transformed into 20ms anyway.

We're waiting at least 20ms even when the buffer allows less to write, we
may not max out the value anymore.

And use the vlc_tick conversion macros

it can never be negative

It is always 0

otherwise a DTS of 0 is not allowed

otherwise a PTS of 0 is not allowed

The variables are not used after that