Add ctts box implementation to handle muxing B-frame videos.
Add method convertPresentationTimestampsToCompositionOffset to
provide sample offsets. Return empty ctts box in case of video
does not contain B-frame. Add ctts box to MoovStructure to handle
muxing the video containing B-frames.
PiperOrigin-RevId: 628346257
This CL aims to separate Fragmented MP4 related logic in a separate public class.
Earlier all the logic was in a single class `Mp4Muxer`.
PiperOrigin-RevId: 619206661
The new API will take both `creation time` and `modification time`.
Till now, Mp4Muxer wrote `modification time` in both
`creation time` and `modification time` field, which was
incorrect.
PiperOrigin-RevId: 605590623
Changes includes;
1. Public API to enable fMP4 and to pass fragment duration.
2. Added `FragmentedMp4Writer`.
3. Added logic to create fragments based on given fragment duration.
4. Write "moov" box only once in the beginning.
3. Add all the required boxes for current implementation.
4. Unit tests for all the new boxes.
5. E2E test for generating fMP4.
Note: The output file is un seek-able with this first implementation.
PiperOrigin-RevId: 594426486
Mp4Muxer does not support out of order B-frames. Currently it
silently writes out of order B-frames, producing an invalid file (with
negative sample durations).
Although `Mp4Extractor` is somehow able to process this invalid file and
`Exoplayer` is able to play it but that is unexpected.
The `sample.mp4` test file contains B frames. Other test files does not
contain `H264 video + AAC audio` format hence created a new test file by
running `sample.mp4` via `Transformer` after applying some effects.
PiperOrigin-RevId: 594016144
