The Auto level lets the encoder decide which level to use.
Furthermore, some devices allow levels beyond 4.2. Therefore,
we add all levels allowed by H.264. This is of importance,
since using a resolution not supported by the specified level
can trigger undefined behavior on the hardware/kernel.
Explicitly checks to make sure hotkeys are actually down, rather than
both down and up. This was causing the restart hotkey to restart the
media twice, once on key down, once on key up.
When using an IP camera on a local network, we wanted to minimize
delay. In order to achieve minimum delay, we allowed Media Source to
set BufferingMB to 0, and when it is 0, also enable AVFMT_FLAG_NOBUFFER
in the AVFormatContext flags.
The built-in format selector failed in certain cases like UtVideo now
using a differently packeg RGB format. FFmpeg has a format selection
functionality built-in that does pick the correct format however
(avcodec_find_best_pix_fmt_of_list), so we can simply use that instead.
Certain ffmpeg parameters such as "bufsize" or "maxrate" have to be
applied to the context rather than to "priv_data". In order to make sure
options are still passed to the encoder setting set AV_OPT_SEARCH_CHILDREN.
Unbuffered mode is causing the frames of media sources to potentially
have some slight jitter in playback, so instead of using unbuffered mode
with media sources, just leave buffering on. There may be a frame or so
of latency, but it shouldn't be noticeable to most users.
Lookahead requires examining frame data over a large number of frames,
so when pkv added the change to fully reset the encoder when the bitrate
changes, nvenc will invalidate all buffers and basically starts over
from a completely clean slate.
It's possible to make lookahead work when changing the bitrate, but due
to how lookahead seems to works internally in nvenc, it will cause
continually increasing latency every time the bitrate is updated, which
is unideal.
Additionally, when lookahead is enabled, deadlocks can occur when
changing the bitrate in a thread other than the graphics thread.
Currently we allow it to be reset outside of the graphics thread. From
limited investigating, it would appear this deadlock occurs because
nvenc is locking and releasing old textures.
So instead of dealing with all these potential issues, disable the
ability to adjust bitrate when the user has lookahead enabled on nvenc.
It's not really worth implementing dynamic bitrate support when
lookahead is enabled if the latency is just going to continually
increase for every bitrate adjustment anyway.
If a user has a tremendous amount of media files, this can cause
instability. Instead, make hardware decoding something the user has to
explicitly enable.
Although hardware decoding was technically enabled by default even
before we fixed it, fixing it was essentially a change to defaults for
users because it was just not even available before version 24.
Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed. Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.
