Files
TeleportFling/internal/capture/pipewire.go
T
petere 3b3355e002 feat: selectable audio source
Add an audio source picker to the GUI so users can capture a specific
PipeWire device (sink monitor or microphone) instead of only the system
default output.

- vendor go2tv.app/screencast and patch the audio stream to accept a
  target PipeWire node serial (PW_KEY_TARGET_OBJECT); the upstream lib
  only ever auto-connected to the default
- capture: ListAudioSources enumerates PipeWire sinks/sources via pw-dump;
  OpenPipeWire takes the selected node serial
- flinger/config/gui: AudioSource config field, persisted and exposed as
  an Audio source dropdown (default output + enumerated devices)

Also fixes two pre-existing bugs surfaced by stop/start testing:
- engine Stop now waits for the video/audio/stats goroutines before
  destroying the encoder (was a use-after-free SIGSEGV)
- Start/Stop now pause/resume the engine instead of tearing down and
  re-opening the portal session, which the portal cannot reliably do
  in-process (2nd CreateSession returned Ended/cancelled). Capture
  session stays open across stop/start.
2026-09-19 21:44:10 +01:00

87 lines
2.5 KiB
Go

// Package capture provides the PipeWire backend for Wayland screen + audio
// capture.
//
// This uses go2tv.app/screencast (MIT) which implements the full
// xdg-desktop-portal ScreenCast negotiation and then receives frames over
// PipeWire. The portal session is responsible for the screen-share consent
// dialog presented by the compositor (Hyprland in our dev environment).
//
// Frames arrive as raw BGRA at the monitor's native resolution/refresh rate.
// Audio is signed 16-bit, 48 kHz, stereo interleaved PCM from the system's
// default output.
package capture
import (
"errors"
"io"
"go2tv.app/screencast/capture"
)
// PipeWire implements Capture on top of the screencast library.
type PipeWire struct {
stream *capture.Stream
}
// OpenPipeWire opens a PipeWire capture session. streamIndex selects which
// monitor to capture when multiple are present; audioSourceSerial optionally
// selects a specific PipeWire audio node (0 = system default). Triggering the
// portal consent dialog is expected; the compositor decides whether to show it.
func OpenPipeWire(streamIndex int, audio bool, audioSourceSerial uint64) (*PipeWire, error) {
s, err := capture.Open(&capture.Options{
StreamIndex: streamIndex,
IncludeAudio: audio,
AudioSourceSerial: audioSourceSerial,
})
if err != nil {
return nil, err
}
return &PipeWire{stream: s}, nil
}
// Video returns the BGRA frame source.
func (p *PipeWire) Video() FrameSource {
return &pipewireVideo{stream: p.stream}
}
// Audio returns the system audio source, or nil if unavailable.
func (p *PipeWire) Audio() AudioSource {
if p.stream.Audio == nil {
return nil
}
return p.stream.Audio
}
// Close releases the capture session and portal resources.
func (p *PipeWire) Close() error {
return p.stream.Close()
}
// pipewireVideo adapts the screencast io.ReadCloser into FrameSource.
type pipewireVideo struct {
stream *capture.Stream
frame *VideoFrame
}
// NextFrame blocks until the next full frame is delivered. The screencast
// library writes one complete BGRA frame per Read, so we assemble it with
// ReadFull and reuse the underlying buffer across calls.
func (v *pipewireVideo) NextFrame() (*VideoFrame, error) {
w, h := int(v.stream.Width), int(v.stream.Height)
if v.frame == nil {
v.frame = &VideoFrame{
Pix: make([]byte, w*h*4),
Width: w,
Height: h,
Stride: w * 4,
}
}
if _, err := io.ReadFull(v.stream, v.frame.Pix); err != nil {
if errors.Is(err, io.EOF) {
return nil, io.ErrClosedPipe
}
return nil, err
}
return v.frame, nil
}