extractCover method

Future<void> extractCover({ required void onCompleted(File file), void onError(Object, StackTrace)?, String? name, String? outDir, CoverExportFormat format = CoverExportFormat.jpg, double scale = 1.0, int quality = 100, void onProgress(Statistics)?, bool isFiltersEnabled = true, })

Export this selected cover, or by default the first one, return an image File.

The onCompleted param must be set to return the exported File cover

The onError function provides the Exception and StackTrace that causes the exportation error.

If the name is null, then it uses this video filename.

If the outDir is null, then it uses TemporaryDirectory.

The format of the image to be exported, by default CoverExportFormat.jpg.

The scale is scale=width*scale:height*scale and reduce or increase cover size.

The quality of the exported image (from 0 to 100 (more info))

The onProgress is called while the video is exporting. This argument is usually used to update the export progress percentage. This function return Statistics from FFmpeg session.

Set isFiltersEnabled to false if you do not want to apply any changes

Implementation

Future<void> extractCover({
  required void Function(File file) onCompleted,
  void Function(Object, StackTrace)? onError,
  String? name,
  String? outDir,
  CoverExportFormat format = CoverExportFormat.jpg,
  double scale = 1.0,
  int quality = 100,
  void Function(Statistics)? onProgress,
  bool isFiltersEnabled = true,
}) async {
  // file generated from the thumbnail library or video source
  final String? coverPath = await _generateCoverFile(quality: quality);
  if (coverPath == null) {
    if (onError != null) {
      onError(
        Exception('VideoThumbnail library error while exporting the cover'),
        StackTrace.current,
      );
    }
    return;
  }
  final String outputPath = await _getOutputPath(
    filePath: coverPath,
    name: name,
    outputDirectory: outDir,
    format: format,
  );
  final String filter =
      _getExportFilters(scale: scale, isFiltersEnabled: isFiltersEnabled);
  // ignore: unnecessary_string_escapes
  final String execute = "-i \'$coverPath\' $filter -y $outputPath";

  debugPrint('VideoEditor - run export cover command : [$execute]');

  // PROGRESS CALLBACKS
  FFmpegKit.executeAsync(
    execute,
    (session) async {
      final state =
          FFmpegKitConfig.sessionStateToString(await session.getState());
      final code = await session.getReturnCode();

      if (ReturnCode.isSuccess(code)) {
        onCompleted(File(outputPath));
      } else {
        if (onError != null) {
          onError(
            Exception(
                'FFmpeg process exited with state $state and return code $code.\n${await session.getOutput()}'),
            StackTrace.current,
          );
        }
        return;
      }
    },
    null,
    onProgress,
  );
}