Play video files online sequentially without delay/buffering between videos - html

Question

Is it possible to play video online that's made of two or more video files?
Since my original post wasn't clear enough, here's expanded explanation and question.
My site is hosted on Linux/Apache/PHP server. I have video files in FLV/F4V format. I can also convert them to other available formats if necessary. All videos have same aspect ratio and other parameters.
What I want is to build (or use if exist) online video player that plays video composed of multiple video files concatenated together in real-time, i.e. when user clicks to see a video.
For example, visitor comes to my site and sees video titled "Welcome" available to play. When he/she clicks to play that video, I take video files "Opening.f4v", "Welcome.f4v" and "Ending.f4v" and join/merge/concatenate them one after another to create one continuous video on the fly.
Resulting video looks like one video, with no visual clues, lags or even smallest observable delay between video parts. Basically what is done is some form of on-the-fly editing or pre-editing, and user sees the result. This resulting video is not saved on the server, it's just composed and played that way real-time.
Also, if possible, user shouldn't be made to wait for this merging to be over before he/she sees resulting video, but to be able to get first part of the video playing immediately, while merging is done simultaneously.
Is this possible with flash/actionscript, ffmpeg, html5 or some other online technology? I don't need explanation how it's possible, just a nod that it's possible and some links to further investigate.
Also, if one option is to use flash, what are alternatives for making this work when site is visited from iphone/ipad?

Answer 1

An approach that will work on some browsers currently, and on most browsers going forwards is to use the HTML5 Video Media Source Extension mechanism.
This essentially allows you replace a static 'src' file for a video in your HTML5 page, with a dynamic src buffer which you can then fill any way you want using your own Javascript code.
So you can write code to pre-buffer the second video when you get towards the end of the first video and then immediately start adding packets from the second video to the src right after the last packet for the first video.
In very high level terms this looks like:
Your HTML to insert the video where you want it in your page:
.
.
.
<div>
<video id="yourVideo1" controls="" autoplay="" width="320" height="240"></video>
</div>
.
.
.
Your Javascript to provide the source for your video:
//Get the video element
var videoElement = document.getElementById('yourVideo1');
//Create a 'MediaSource' and associate it with this video
var mediaSource = new MediaSource();
video.src = window.URL.createObjectURL(mediaSource);
//Add a listener to the MediaSource object to check for
//the video been opened. In this function you can add your
//code to get the get your videos from the servers and add
//'chunks' to the media source buffer
mediaSource.addEventListener('sourceopen', function(e) {
//Set the format of the source video
var mediaSourceBuffer = mediaSource.addSourceBuffer('video/webm; codecs="vorbis,vp8"');
//Get your video from the web
while (not the end of your video playlist) {
...
//Stream video from server
...
//Add packets received to the media source bufer
mediaSourceBuffer.appendBuffer(receivedVideoPackets);
//If near end of video start fetching next video to
//avoid buffering delay
...
//If end of video go to next video in playlist
...
}
}, false);
Look at the HTML5 Rocks demo below to see this in action (for a slightly different usecase).
Given how tricky video manipulation is and the multitude of formats etc, it would be much easier for you if one of the established video players provided the functionality out of the box so I would still try their forums as mentioned in the comment, but at least you know it is technically possible.
The MSE spec is available here:
http://w3c.github.io/media-source/
And a good intro blog and demo is here (make sure your browser supports MSE - latest version of Chrome does):
http://updates.html5rocks.com/2011/11/Stream-video-using-the-MediaSource-API
You can find latest browser support here:
http://www.jwplayer.com/html5/mediasource/

Answer 2

Use two video elements, first visible and second display:none for buffering.
After first video playing, check currentPosition and currentDuration,
specify second video preloader prepare visible video player's buffer data.
First video element's SRC could be specified anytime for seamless playing.