On 10/8/2015 3:09 AM, ken wrote:
An acquaintance is considering videocasting speakers at a conference and using a Twitter product called Periscope. I'd like to recommend an open source solution. While I've never offered videos over the web, I have made audios available, and all it entailed was placing the file on the website and putting its url on a visible webpage. I wouldn't think any more than that is required for video. True?
video files are too big for that model. an hour long video of medium good quality is often 1GB. you want a 'player' that runs within browsers, probably using HTML5 as Flash is awful. to feed this, you need a streaming protocol that knows how to throttle the video to a suitable data rate for the clients actual connection, and lets the viewer random hop to arbitrary points in the video stream without having to download the whole file before playing. FOSS html5 video streaming servers exist but aren't easy to setup. nginx has a plugin for this.
anyone streaming video for a significant number of viewers ends up having to get involved with a content delivery network, or they get killed with uplink speed requirements. even 10 concurrent viewers of medium quality video can peg a 100baseT uplink, and most hosting providers will start charging transit fees per gigabyte if this happens too often.
"Live" videocasting is likely a different animal. How is this accomplished?
painfully, and usually via proprietary transports.
Also, which video formats are recommended-- FOSS of course preferred, but a FOSS format for which there are readily available client apps on the major platforms (MS, Android, OSX, Linux).
with video files/streams you have 3 elements. the container format, the video codec, and the audio codec. while some container formats, like MKV, are open source, the codecs they contain rarely are, all the MPEG formats use patents, and its a tangled mess. MP4 h.264/x.264 aka AVC is probably the best compromise format for video quality and size. h.265/HEVC is even better but fewer clients can play it. audio is usually AAC, AC3, or MP3, all of which are patent encumbered. There are what I personally consider 'screwball' open source codecs like the Ogg family, and then there's the WebM streaming format used by html5, of which I know very little.
I finally came to the conclusion that the best way to host videos on a website was to load them onto vimeo or youtube, and embed their player html in your webpage, let THEM deal with the streaming aspects and bandwidth.
-- john r pierce, recycling bits in santa cruz _______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx https://lists.centos.org/mailman/listinfo/centos
