Enable the attribute "console" of custom_target() introduced in meson
0.48. This allows to get a feedback of what gradle does (which can takes
a very long time).
This produces warnings because we declare to support meson >= 0.37, but
we don't want to stop supporting older versions for that. Older versions
just ignore the option:
> WARNING: Unknown keyword arguments in target scrcpy-server: console
Newer meson versions use it, but warn because we declare supporting
older versions:
> WARNING: Project targetting '>= 0.37' but tried to use feature
> introduced in '0.48.0': console arg in custom_target
Meson does not support conditional branches to suppress such warnings,
so just keep the warnings.
Headers seem to be a bit different in Apple land and you need to include
stddef.h explicitly to the NULL declaration.
This also makes the code a bit more correct, as stddef.h is the header
in the C standard that defines NULL
(https://en.cppreference.com/w/cpp/header/cstddef).
We need several FIFO queues (a queue of packets, a queue of messages,
etc.).
Some of them are implemented using cbuf, a generic circular buffer. But
for recording, we need to store the packets in an unbounded queue until
they are written, so the queue was implemented manually.
Create a generic implementation (using macros) to avoid reimplementing
it every time.
The record file was written from the stream thread. As a consequence,
any blocking I/O to write the file delayed the decoder.
For maximum performance even when recording is enabled, send
(refcounted) packets to a separate recording thread.
To packetize the H.264 raw stream, av_parser_parse2() (called by
av_read_frame()) knows that it has received a full frame only after it
has received some data for the next frame. As a consequence, the client
always waited until the next frame before sending the current frame to
the decoder!
On the device side, we know packets boundaries. To reduce latency,
make the device always transmit the "frame meta" to packetize the stream
manually (it was already implemented to send PTS, but only enabled on
recording).
On the client side, replace av_read_frame() by manual packetizing and
parsing.
<https://stackoverflow.com/questions/50682518/replacing-av-read-frame-to-reduce-delay>
<https://trac.ffmpeg.org/ticket/3354>
Recent versions of meson complain about an option having name starting
with "build_":
> DEPRECATION: Option uses prefix "build_", which is reserved for Meson.
> This will become an error in the future.
Use "compile_" instead.
