Files
ten31-transcripts/Ten31Transcripts/Adapters/SignalAdapter.swift
T
Grant Gilliam a56b47143c Signal: detect the white speaking border (not a coloured one)
Signal's active-speaker cue is a 3px #ffffff rounded border (saturation ≈ 0),
which the saturation-based highlight detector could never see. Per the
Signal-Desktop source review:

- FrameSampler.thinWhitePoints: grid-sample near-white pixels that sit on a
  THIN structure (a non-white pixel within edgeGap on some axis) so a border/
  ring counts but a solid white blob (face, bright video) does not.
- GridCallAnalyzer: combine coloured (saturated) + white (thin) highlight
  pixels; exclude name-text regions so the white footer name can't be mistaken
  for the border; estimate the tile UP from the name footer (nameAtBottom);
  attribute each highlight pixel to exactly one tile by containment (nearest
  centre as tiebreak) so a border can't bleed into an adjacent tile.
- SignalAdapter: white border on, coloured off, name-at-bottom geometry.

Synthetic 4-tile harness now isolates each speaker with no adjacent-tile bleed;
all 15 XCTest cases pass. Real-screenshot geometry calibration still pending.
2026-06-06 09:52:10 -05:00

39 lines
1.6 KiB
Swift

import Foundation
import CoreVideo
/// Signal Desktop adapter. Signal shows avatars/initials with a coloured ring
/// around the active speaker; names may also be available via the Electron
/// Accessibility tree (preferred over OCR when we enable it). Geometry/threshold
/// here are first-pass and will be calibrated against real Signal screenshots.
struct SignalAdapter: AppAdapter {
static let bundleIDs = ["org.whispersystems.signal-desktop"]
let adapterVersion = "signal-0.1.0"
let preferredFPS = 3
private let analyzer: GridCallAnalyzer
init() {
var config = GridCallAnalyzer.Config()
// Signal's speaking cue is a 3px WHITE rounded border (not coloured); the
// name is a bottom footer, so the tile extends up from it. Geometry tuned
// with real fixtures. (Gotchas, per Signal source: NO border in 1:1 calls
// fall back to mic-VAD/audio pill and in Speaker view the large tile is
// the speaker; both handled at a higher level later.)
config.nameAtBottom = true
config.detectWhiteBorder = true
config.detectColoredBorder = false
config.tileExpandX = 2.4
config.tileExpandY = 4.8
self.analyzer = GridCallAnalyzer(config: config)
}
func analyze(frame: CVPixelBuffer, at t: TimeInterval) -> [SpeakerObservation] {
analyzer.analyze(pixelBuffer: frame, at: t)
}
// Exposed for fixture/synthetic tests.
func analyze(cgImage: CGImage, at t: TimeInterval) -> [SpeakerObservation] {
analyzer.analyze(cgImage: cgImage, at: t)
}
}