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    <p><strong>UPDATE 12/2014</strong> <em>FYI, there is a new API on its way called <strong><a href="https://developer.mozilla.org/en-US/docs/Web/API/MediaRecorder_API" rel="nofollow noreferrer">MediaRecorder</a></strong>. Currently only supported in Firefox, and in an early state, but something to have in mind.</em></p> <h1>mediaStream and local storage</h1> <p>In pure local environment you can't and won't get a very good result. You can save out the frames using the canvas element by drawing onto it and store jpeg images to a local storage from the video stream together with the audio (which must be saved separately) and then in post use a library to create for example a MJPEG file (AFAIK there isn't currently any that supports audio).</p> <p>You will run into several issues with this approach however: it will take much time to use JavaScript to process all this information - just saving a frame as jpeg, converting it to blob and save it to the file system or indexed DB will consume most (or more) of the time budget you have available for a single frame.</p> <p>You will not be able to synchronize the video frames with the audio properly - you can save a time-stamp and use that to "correct" the frames but your FPS will most likely vary creating a jerky video. And even if you get the sync in somewhat order time-wise you will probably face problems with lag where audio and video does not match as they are initially two separate streams.</p> <p>But videos are very rarely above 30 FPS (US) or 25 FPS (Europe) so you won't need the full 60 FPS rate the browser <em>may</em> provide. This gives you a little better time budget of about 33 milliseconds per frame for US (NTSC) system and a little more if you are in a country using the PAL system. There is nothing wrong using an even lower frame rate but at a certain point (&lt; 12-15 FPS) you will start noticing severe lack of smoothness.</p> <p>There are however many factors that will influence this such as the CPU, disk system, frame dimension and so forth. JavaScript is single threaded and canvas API is synchronous so a 12-core CPU won't help you much in that regard and Web Workers' usefulness is currently limited pretty much to more long-running tasks. If you have a lot of memory available you can cache the frames in-memory which is do-able and do all processing in post which again will take some time. A stream recorded at 720P @ 30 FPS will consume minimum 105 mb per second (that's just raw data not including the browser's internal handling of buffers which may double or even triple this).</p> <h1>WebRTC</h1> <p>A better solution is probably be to use WebRTC and connect to a server (external or local) and process the stream there. This stream will contain synchronized audio and video and you can store the stream temporary to disk without the limitations of a browser sand-boxed storage area. The drawback here will be (for external connections) bandwidth as this may reduce the quality, as well as the server's capability.</p> <p>This opens up the possibility to use for example Node.js, .Net or PHP to do the actual processing using third-party components (or more low-level approach such as using compiled C/C++ and CGI/piping if you're into that).</p> <p>You can check out this open source project which supports recoding of WebRTC streams:<br> <a href="http://lynckia.com/licode/" rel="nofollow noreferrer">http://lynckia.com/licode/</a></p> <p>The Licode project provides a NodeJS client API for WebRTC so that you can use it on the server side, <a href="http://lynckia.com/licode/client-api.html#erizofc" rel="nofollow noreferrer">see the docs</a></p> <p>And this is basically how far as you can go with current state of HTML5.</p> <h1>Flash</h1> <p>Then there is the option of installing Flash and use that - you <a href="https://stackoverflow.com/questions/1973002/save-video-captured-from-webcam-using-flash">will still need a server</a> side solution (Red5, Wowza or AMS).</p> <p>This will probably give you a less painful experience but you need to have Flash installed in the browser (obviously) and in many cases there is a higher cost factor due to licenses (see <a href="http://www.red5.org/" rel="nofollow noreferrer">Red5 for a open-source</a> alternative).</p> <p>If you are willing to pay for commercial solutions there are solutions such as this:<br> <a href="http://nimbb.com/" rel="nofollow noreferrer">http://nimbb.com/</a></p>
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