Android: Stream Camera Data and Write it to Server

Question

I stream webcam data to my client.

I can see the data is arriving by listening on('data'). However, when I create it I am not able to view it and it's probably garbage data or missing some headers. VLC cannot play it.

My next step is to make it real-time streamable to browser.

What am I doing wrong?

net = require('net');
fs = require('fs');

// Start a TCP Server
net.createServer(function (socket) {    
    console.log("client connected");
    var file = fs.createWriteStream("temp.mp4");
    socket.pipe(file, {end: false});

    socket.on('end', function(){
        console.log("ended");
    });
}).listen(5000);

I tested to see if did it really capture video output:

$ mediainfo temp.mp4 

General
Complete name                            : temp.mp4
Format                                   : H.263
Format version                           : H.263
File size                                : 126 KiB

Video
Format                                   : H.263
Width                                    :  pixel0
Height                                   :  pixel0
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Compression mode                         : Lossy

And this is the following Android code for setting mediaRecorder (Assume socket is connected, no problem)

    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
    mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
    mediaRecorder.setVideoSize(320, 240);
    mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.DEFAULT);
    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);

    ParcelFileDescriptor pfd = ParcelFileDescriptor.fromSocket(socket);     
    mediaRecorder.setOutputFile(pfd.getFileDescriptor());

    mediaRecorder.setMaxDuration(5000);
    mediaRecorder.setMaxFileSize(5000000);

Answer 1

There are a few open source projects that solve this problem, such as Spydroid (browser/VLC streaming) and Android IP Camera (browser streaming). Your implementation seems similar to Spydroid, so maybe you can adapt some of its code.

The central problem is that MediaRecorder is writing raw video frames into the socket. It needs to wait until the video is finished to write the headers, but they need to appear at the beginning of the file. Since the socket is not seekable, the headers can't be written at the correct location. The projects linked above deal with this problem by packetizing the stream into RTSP (Spydroid) or "streaming" a series of still images to the browser (Android IP Camera).