trimVideo method

@override Future<MediaInfo> trimVideo(VideoTrimRequest request, String jobId)

Exports the trimmed range. Progress for jobId arrives on progress while this is in flight.

Implementation

@override
Future<MediaInfo> trimVideo(VideoTrimRequest request, String jobId) async {
  trims.add(request);
  final error = nextTrimError;
  if (error != null) {
    nextTrimError = null;
    throw error;
  }

  for (final tick in progressTicks) {
    // Yield between ticks. A real export delivers progress over a channel,
    // never in the same microtask as its result — emitting synchronously
    // would let the result outrun the ticks and drop them.
    await Future<void>.delayed(Duration.zero);
    if (_cancelled.contains(jobId)) break;
    _progress.add(TrimProgress(jobId, tick));
  }
  if (exportDuration > Duration.zero) {
    await Future<void>.delayed(exportDuration);
  }
  // Let the last tick reach its listeners before the result completes and
  // the editor tears the subscription down.
  await Future<void>.delayed(Duration.zero);
  if (_cancelled.remove(jobId)) {
    throw PlatformException(
      code: kMonolensCancelled,
      message: 'Export cancelled',
    );
  }

  final source = files[request.sourcePath] ?? defaultInfo(request.sourcePath);
  return MediaInfo(
    path: request.outputPath,
    width: source.width,
    height: source.height,
    durationMs: request.endMs - request.startMs,
    byteSize: 4096,
  );
}