I use JWPlayer to play videos from the server. Videos are encoded using h.264 codec. If i open them in browser with h.264 support - video plays nicely and i can seek it, because server returns 206 header browser understands that its partial content. But if i try to play same video on Opera, for example, flash player is being used and it receives 200 OK! 2 problems here:
I can't seek the video, until part of it is downloaded
If the video is not "properly" encoded player can't even start playing it, until file is fully downloaded.
Is there something wrong with flash properly asking/understanding http headers?(i've never worked with flash before, so maybe my question is a bit silly and i just don't know flash's limitations)..
1) You need to have pseudo streaming enabled, for Flash - http://www.longtailvideo.com/support/jw-player/28855/pseudo-streaming-in-flash, if you can provide a link though, I will take a look at exactly what is going on here, I am more or less guessing about this one. HTML5 does not require a pseudo streaming module to be installed on the server side, though. In Flash, the default is progressive download, so you can only seek to downloaded parts, and in html5, this is not the case.
2) Yes, that is because of encoding. If your MP4 files cannot be seeked before they are completely downloaded, you will have to fix the MOOV atom (it contains the seeking information) located at the end of your video. Use this little application to parse your videos and add the necessary cue points - http://renaun.com/blog/2010/06/qtindexswapper-2/
Also, encoding via HandBrake - http://handbrake.fr/, can fix this as well, so the above tool wouldn't be necessary. You can encode using HandBrake, and enable "web optimized", which does the same this as the Index Swapper Tool. HandBrake also has command line encoding options as well.
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Is there any way to stream mkv files on webpage using javascript/html or any other technologies? I found many questions about this, but I really want to know the answer - is this possible in any way? Maybe ajax, javascript, php, html? Maybe some external libraries? Anything?
I was wondering how youtube works. Is there possible to upload mkv file? Is so, how that videos are streaming to end user?
I know that browser doesn't support mkv natively, but maybe is some way to forcing html to do that?
Any help will be appreciated.
YouTube most probably works using the DASH protocol format. On the server side, the source audio and source video are separately divided into segments of different bitrate/quality. A manifest keeps an index of all possible segments values and their location. This allows to switch quality during playback in the player.
On the client side, the DASH (should be the same with the other main technology: HLS) manifest is used by the player to locate the segments to load in order to feed the content in two separate SourceBuffer, one for audio and one for video and both are being played synchronously together in the MediaSource. For an example player that handles this, see the Shaka Player developed by Google.
Conclusion, there is no need to use a container like mkv but each channel (video, audio) needs to point to a browser supported codec encoded segments.
You don't need anything special for streaming pre-recorded media files. A normal HTTP/1.1 or HTTP/2 server will work just fine. The browser is generally capable of seeking into the file using range requests.
Matroska (MKV) is a container format, and it actually is widely supported because it's basically the same as WebM. WebM is a subset of Matroska... the key differences being that there are suggested codecs for use. (Matroska itself supports almost anything.)
Your audio and video tracks in the file can use a variety of codecs... the key is to use codecs compatible with browsers. Opus for audio and VP8 for video will take you far.
From there, simply reference your video file in a <video> tag.
Is there a way to control how much of the file will be buffered ahead, once you click play, much like Youtube once did?
If you use the built-in video support in the browser then there is no way to control the amount of data that's being buffered. It depends on the browser implementation and there is no API to control it.
Browser implementations are quite good and typically a browser buffers just a small portion of the video before playback begins. Browsers don't download the whole file. However if a file gets completely downloaded by the browser before playback begins then possible causes include:
Maybe the file is very small and the browser has decided to buffer the whole file in memory.
Maybe the header of the file (required to initialize the video decoder) is not at the start of the file but at the end and the browser has to download the whole file until it reaches it. This is uncommon nowadays but old video encoders used to place the mp4 header at the end of the file instead of at the beginning because it simplified the encoder's implementation.
I've noticed that browsers behave oddly if an mp4 file doesn't have a segment index (used for seeking) in its header. Some browsers download the whole file so that they can build a segment index themselves.
If your server is old/misconfigured then the browser may decide that range requests are not supported and download the whole file (or disable seeking).
If you require to control the buffered amount before playback begins then you have to use a more sophisticated protocol (MPEG-DASH, HLS) and a javascript player that allows you to control this parameter. Youtube use MPEG-DASH and have their own player that they've developed over the years.
I'm pretty sure you c an't stop the HTML5 video from buffering the entire video, but here is a useful link for working out how much of the video has been buffered.
https://developer.mozilla.org/en-US/Apps/Build/Audio_and_video_delivery/buffering_seeking_time_ranges
Like mylescc mentioned, preventing the video element from buffering might not be possible, without a workaround (described in a similar posting). However, depending on your use case, you can also make use of existing player implementations, which provide this functionality, like the bitmovin player, dash.js, etc.
I am trying to upload an MP4 file. But with this specefic file only the sound content is displayed.
With all my other videos there is no problem only with this specefic one.
i found the following SO question:
HTML5 video of type video/mp4 playing audio only
Where he suggest to find a converter.
Does anyone know if this could be the problem and how do i secure that regardless of what video my user uploads that it will always be able to play?
Yes, this can be a problem.
You have not written about your server limitations, so if you have the possibility to execute converters (like ffmpeg) then this is the best solution. This way you can also guarantee fixed resolution, framerate and various other properties, and your server won't eat up all the space if someone uploads a 2GB video... (Users can be dumb sometimes.)
If you cannot run ffmpeg on the server then try reading some about how can you detect codecs on your server, in the language you use, etc. Then, if you still want to, post a specific question.
Also try opening your videoplayer page with different browsers (Chrome, FF, IE at least). They might not support the codecs the same way.
I'm trying to figure out if web based audio streaming sites use the Web Audio API for playback or if they rely on the audio element or something else.
Since the user of an audio streaming service typically doesn't need more functionality than starting and stopping the audio, then I guess that the audio element is enough. If a VU-meter is required then I would guess the Web Audio API would be used since it has an built in analyser node. But since IE doesn't support the API then I suppose you'd rather use the audio element and reach the IE users than using fancy extras such as an VU-meter.
I've been looking at the source code for Spotifys web player, Grooveshark, BBC radio and the Polish public radio but I find neither audio elements or use of the Web Audio API. I did find that the Swedish public radio (sr.se) makes use of the audio element though.
I'm not asking for anyone to go through the JavaScript source code for me, but rather if someone who is familiar with the subject could point me in the right direction.
I don't know of any internet radio services playing back their streams with the Web Audio API currently, but I wouldn't be surprised to find one. I've been working on one myself using Audiocog's excellent Aurora.js library, which enables codecs in-browser that wouldn't normally be available, by decoding the audio with JavaScript. However, for compatibility reasons as you have pointed out, this would be considered a bit experimental today.
Most internet radio stations use progressive HTTP streaming (SHOUTcast/Icecast style) which can be played back within an <audio> element or Flash. This works well but can be hard to get right, especially if you use SHOUTcast servers as they are not quite 100% compatible with HTTP, hurting browser support in some versions of Firefox and a lot of mobile browsers. I ended up writing my own server called AudioPump Server to get better browser and mobile browser support with HTTP progressive.
Depending on your Flash code and ActionScript version available, you might also have to deal with memory leaks in creative ways, since by default Flash will keep all of your stream data in memory indefinitely as it was never built to stream over HTTP. Many use RTMP with Flash (with Wowza or similar on the server), which Flash was built to stream with to get around this problem.
iOS supports HLS which is basically a collection of static files served by an HTTP server. The encoder writes a chunk of the stream to each file as the encoding occurs, and the client just downloads them and plays them back seamlessly. The benefit here is that the client can choose a bitrate to stream and, raising quality up and down as network conditions change. This also means that you can completely switch networks (say from WiFi to 3G) and still maintain the stream since chunks are downloaded independently and statelessly. Android "supports" HLS, but it is buggy. Safari is the only browser currently supporting HLS.
Compatibility detection is not something you need to solve yourself. There are many players, such as jPlayer and JW Player which wrangle HTML5 audio support detection, codec support detection, and provide a common API between playback for HTML5 audio and Flash. They also provide an optional UI if you want to get up and running quickly.
Finally, most stations do offer a link to allow you to play the stream in your own media player. This is done by linking to a playlist file (usually M3U or PLS) which is downloaded and often immediately opened (as configured by the user and their browser). The player software loads this playlist and then connects directly to the streaming server to begin playback. On Android, you simply link to the stream URL. It will detect the Content-Type response header, disconnect, and open its configured media player for playback. These days you have to hunt to find these direct links, but they are out there.
If you ever want to know what a station is using without digging around in their compiled and minified source code, simply use a tool like Fiddler or Wireshark and watch the traffic. You will find that it is very straightforward under the hood.
We use Web Audio for streaming via Aurora.js using a protocol very similar to HTTP Live Streaming. We did this because we wanted the same streaming backend to serve iPhone, Android and the web.
It was all a very long and painful process that took over 6 months of effort, but now that its all finished, its all good.
Have a look at http://radioflote.com and feel free to shoot questions or clarifications regarding anything. Go ahead and disassemble the code if you want to. Not a problem.
For the last two month I have been trying to "fool" safari into thinking that it's looking at a file on the server, which in fact is a live video stream from a camera encoded and muxed upon request using Gstreamer into a format that is supported by the browser. Since HTML5 supports progressive video downloads this should at least be possible in theory.
My conclusion is that this gets quite complicated considering that browsers make a partial content request when downloading video files in HTML5, mainly for the sake of seeking. If the server lacks support for this feature the video is not played until the file is completely downloaded.
Have anyone else tried this approach with more success? Or should I just give up and wait for true live video support like RTSP to be integrated into browsers.
Cheers.
This article provides some useful tips: https://developer.mozilla.org/en/Configuring_servers_for_Ogg_media
Are you serving the X-content-duration header?
You have two possibilies.
With H.264 you can emulate a file with fragmented structure: ISO container (.mp4) with movie fragment atoms (MOOF's).
The other option is Google's WebM. Clients can "join in" the stream any time thanks to MKV file's structure. For best results the first frame transmitted to the client should be akeyframe.
If you only need video but not audio, "Motion JPEG" can do it. It's not HTML5 but a Netscape-era feature.
http://en.wikipedia.org/wiki/Motion_JPEG#M-JPEG_over_HTTP