Simply use two packet_buffers that are double-linked lists of
AVPacket structs. This way we can control which packets to feed
to the decoders at the right time.
This solves the playback problem with the MP4 files.
The video fifo can be removed, since we have a ring buffer in it's
place. This removes unneeded copy operations and as a positive side
improves overall decoding speed.
Makes 8k60p SW and 4k60p HW decoding possible on my system.
For now the ring buffer is 32 images deep. This limitation will
be removed, once audio and video decoder have their own
packet handling.
Using a ordered ring buffer and a thread pool, the color space
conversion is not multi-threaded based on frames. I tried
to implement slice based threading, but libswscale did produced
highly distorted pictures without obvious reason.
This approach introduces some more "lag" when decoding and skipping,
but shouldn't be affect the user negatively, since movie
watching is not lag sensitive, as long as the A/V is synchronized.
Change default to software decoding.
SW decoding is the most robust and fasted method of decoding right now.
Users should enable hw based decoding if their system requires it
and it's actually beneficial for them.
Fix deadlocks when seeking and decrease RAM usage.
Decrease memory allocation by reusing AVFrames.
