filter_chain_Reset is reserved for restating new input/output formats and does
not allow empty format anymore.

filter_chain_Clear doesn't change the input/output formats, only remove all the
filters.

This way we can use filter_NewPicture() which will use the allocator of
the filter if there is one.

Set the whole video_filter_owner_t back and forth to pretend it's the real
"owner".

Remove the container_of inline function only used once.

spu filters don't set an owner for the filter chain (for now)

That's only field of the structure that was used

SPU doesn't use callbacks to get the subpictures from an the owner.

No need for a constant callback.

The blocks on the decoder input are not even decoded frames and they can be
NULL. The decoded frames are already counted when the pictures/audio blocks
come out of the decoder and are queued for playback.

The decoder and the DecoderThread are dead at this point, so we have nothing
to protect against.

ModuleThread_ for the decoder output thread(s) which can be the
DecoderThread for synchronous decoders and any thread otherwise (concurrent
calls are not allowed).

DecoderThread_ for internal DecoderThread calls.

It's like P010/NV12 but for up to 16 bits sources

That's how it's done in DecoderProcessFlush(). No need to unlock/lock again
just for that.

Similar to how it's done in DecoderProcessFlush().

It makes it clearer when variables are accessed under lock. It also avoids
locking in some cases if not needed.

Should avoid frame delay in most cases.
Will still re-render at blending time if dst
has changed in between.

simplified and allow working with picture
without the spu channel queue entry

No need for a label to jump to if it's only used at one location.

And reorder DecoderPlayAudio() to match the same logic as the Video one.

The VLC_TICK_INVALID check is done early. After that we don't need to check it
anymore.

Especially before we check this date against the i_preroll_end.

Especially before we check this date against the i_preroll_end.

No need for pointers.

No need for pointers.