The receiver window never appeared on Wayland. Two causes:
- The window was created on the main thread while event pumping and
presenting ran on the render thread. SDL's Wayland backend requires a
window's creation, event processing, drawing, and destruction to
happen on one thread; a cross-thread surface simply never maps, with
no error reported. The renderer now lives entirely on the render
thread, with a condition-variable handshake so ReceiverPipeline::
start() still reports renderer failures and timeouts.
- On Wayland a window is invisible until the first render commit, so
even a healthy receiver showed nothing while waiting for a stream.
The renderer presents one blank frame at init: the window is visible
immediately, black until video arrives.
Also log 'stream started (WxH)' when the first frame decodes and the
first rendering failure, which is what made the remaining debugging
observable.
Validated headlessly end-to-end: a synthetic solid-color RTP feed drove
the real receiver over localhost UDP; the window mapped, reported
'stream started (320x240)', and a grim screenshot of the window region
showed the fed color (V=198, SATAVG=74 during the red feed). Phase 5
marked complete in docs/PHASES.md; current phase is now Phase 6.
Add the sc_network library: RFC 3550 RtpHeader/RtpPacket serialize and
parse (the receiver tolerates CSRC lists, extension headers, and
padding by skipping/stripping them) and RFC 6184 H.264 payloading via
H264Packetizer/H264Depacketizer.
The packetizer splits Annex-B frames into NAL units (3- and 4-byte
start codes), emitting single-NAL packets or FU-A fragments within the
configured MTU, with the marker bit closing each frame and randomized
SSRC/sequence by default. The depacketizer reassembles access units
with 3-byte start codes, so both start-code widths round-trip
byte-exactly; frames damaged by sequence gaps or missing fragments
are dropped until the Phase 7 loss-recovery work.
test_rtp covers header and packet round-trips, malformed-input
rejections, splitter behavior, FU-A chunk bounds, full packetize ->
depacketize round-trip, gap dropping, marker-only frame separation,
sequence wrap, and empty inputs. meson test 3/3, valgrind clean.
Implement the xdg-desktop-portal ScreenCast backend via libportal: a
blocking portal handshake (interactive source picker), a PipeWire stream
on the portal's node enumerating BGRx/BGRA/RGBx/RGBA, and a latest-frame
slot handing frames to next_frame(). stop() is thread-safe; teardown
follows the order PipeWire requires. All proxy operations run under the
thread-loop lock to satisfy the protocol extension context checks
('impl_ext_end_proxy called from wrong context' otherwise).
The encoder now accepts padded strides for packed RGB inputs (real
PipeWire row pitches) and maps the new PixelFormat::Bgrx to
AV_PIX_FMT_BGRA.
Add tools/capture_smoke: a manual smoke tool (interactive, not in
meson test) that captures N frames, encodes them, and writes a
self-contained Annex-B elementary stream with prepended SPS/PPS.
Validated manually on Wayland/Hyprland: 2256x1504 H.264 elementary
stream, ffprobe clean. Phase 3 marked complete in docs/PHASES.md.
Add FFmpeg-based encoder/decoder with SPS/PPS extradata, Annex-B output
normalization, low-latency libx264 settings, and a round-trip unit test.
Includes review hardening: cached SwsContext, bitrate-only rate control,
std::byte/uin8_t cast helpers, and richer test assertions.
fegger