da724c8cc4
We introduce SubtitleParser.Factory that supports no formats to be used FragmentedMp4Extractors that will not do any subtitle parsing on the extraction side. We also slowly move away from using SubtitleTranscodingExtractor to SubtitleTranscodingExtractorOutput (hence making it public). This is required by individual Extractor impls so that they can start using SubtitleTranscodingExtractorOutput rather than be wrapped by SubtitleTranscodingExtractor. The latter is to be deprecated after all the subtitle related Extractors have achieved this migration. PiperOrigin-RevId: 596942147