videoCodecArgs static method

List<String> videoCodecArgs({ required Size canvas, required int fps, required ExportQuality quality, required bool preview, bool hardware = false, })

Encoder arguments for canvas at fps: hardware H.264 on Android when hardware is set, otherwise x264 (VideoToolbox on Apple platforms).

Implementation

static List<String> videoCodecArgs({
  required Size canvas,
  required int fps,
  required ExportQuality quality,
  required bool preview,
  bool hardware = false,
}) {
  if (hardware && Platform.isAndroid) {
    final bitsPerPixel = preview ? 0.06 : quality.bitsPerPixel;
    final bitrate = (canvas.width * canvas.height * fps * bitsPerPixel)
        .clamp(1000000, 40000000)
        .round();
    return [
      '-c:v', 'h264_mediacodec',
      '-b:v', '$bitrate',
      '-g', '${fps * 2}',
      // Every Android encoder accepts NV12; planar YUV is optional.
      '-pix_fmt', 'nv12',
    ];
  }
  if (Platform.isIOS || Platform.isMacOS) {
    final bitsPerPixel = preview ? 0.05 : quality.bitsPerPixel;
    final bitrate = (canvas.width * canvas.height * fps * bitsPerPixel)
        .clamp(800000, 60000000)
        .round();
    return [
      '-c:v', 'h264_videotoolbox',
      '-b:v', '$bitrate',
      if (preview) ...['-realtime', 'true'],
    ];
  }
  return preview
      ? ['-c:v', 'libx264', '-preset', 'ultrafast', '-tune', 'zerolatency', '-crf', '30']
      : ['-c:v', 'libx264', '-preset', 'veryfast', '-crf', '${quality.crf}'];
}