SharpMP4 0.1.0

SharpMP4

Simple lightweight fragmented mp4 (fmp4) reader/writer. Supports H264/H265/H266/AV1 for video and AAC/Opus for audio. No platform dependencies, easily portable cross-platform. It was designed to be a stream-in and stream-out solution for recording streams from IP cameras into fragmented MP4.

Read MP4

To parse an existing mp4/mov/m4v file, first you have to get the stream:

using (Stream inputFileStream = new BufferedStream(new FileStream("frag_bunny.mp4", FileMode.Open, FileAccess.Read, FileShare.Read)))
{
    ...
}

Create a new Container and call Read to get the in-memory representation of all the boxes.

var mp4 = new Container();
mp4.Read(new IsoStream(inputFileStream));    ...

To process this in-memory representation and read the audio/video samples, create a new VideoReader:

VideoReader videoReader = new VideoReader();
videoReader.Parse(fmp4);

Now it is possible to get all the tracks from the video:

IEnumerable<ITrack> tracks = videoReader.GetTracks();

To read the first track samples, call:

uint trackID = tracks.First().TrackID;
MediaSample sample = videoReader.ReadSample(trackID);

Where trackID is the ID of the track you want to read.

Build MP4

To write MP4 into a file, you first have to create the file:

using (Stream output = new BufferedStream(new FileStream("bunny_out.mp4", FileMode.Create, FileAccess.Write, FileShare.Read)))
{
    ...
}

Next, create the builder depending upon the output format. Currently, there are two builders - FragmentedMp4Builder and Mp4Builder.

IMp4Builder outputBuilder = new Mp4Builder(new SingleStreamOutput(output));

Add the H264 video track to the builder instance:

var videoTrack = new H264Track();
outputBuilder.AddTrack(videoTrack);

Add the AAC audio track to the builder instance:

var audioTrack = new AACTrack(2, 44100, 16);
outputBuilder.AddTrack(audioTrack);

Pass the track samples to the builder as follows:

byte[] nalu = ...;
outputBuilder.ProcessTrackSample(videoTrack.TrackID, nalu);

...

byte[] aac = ...;
outputBuilder.ProcessTrackSample(audioTrack.TrackID, aac);

When done, call FinalizeMedia to create the video file:

outputBuilder.FinalizeMedia();

Extensibility

Logging

There is a Log class where you can supply your own delegates for all the actions like:

Log.SinkWarn = (message, exception) => 
{
    ...
};

You can also enable/disable different trace levels like:

Log.WarnEnabled = false;

Credits

Huge inspiration for this project was the mp4parser https://github.com/sannies/mp4parser, thank you very much!