R – Should I encode flash videos using cbr or vbr for streaming

flashflvstreaming

We are going to be hosting some videos that will be streamed (not progressive download). Which is recommended? CBR (constant bit rate) or VBR (variable bit rate) encoding?

Best Answer

Constant bit rate is intended for streaming media, so that would be the natural choise.

Variable bit rate will give you slightly better quality in relation to file size, but you get much greater variations from the average bit rate. If the average bit rate is close to the capacity of the user's connection, they may experience that the video stops for a while in parts where the bit rate is over the average. So, if the capacity of your user's connection is much higher than the average bitrate that you choose, VBR works better.

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How to do Flash pseudo-streaming

@yoavf - I think the OP is interested in server-side aspects of streaming on-demand h.264 inside of FLV files. Reuse of existing players would be nice for him, I think. Or maybe that is my own needs coming out? <:S

From yoavf's second link, there is another link to Tinic Uro's What just happened to video on the web? . A relevant quote:

Will it be possible to place H.264 streams into the traditional FLV file structure? It will, but we strongly encourage everyone to embrace the new standard file format. There are functional limits with the FLV structure when streaming H.264 which we could not overcome without a redesign of the file format. This is one reason we are moving away from the traditional FLV file structure. Specifically dealing with sequence headers and enders is tricky with FLV streams.

So, it seems one can either tinker with ffmpeg encoding (if that is how you are getting your FLVs, like I am) or one can get into the new format. Hmmmm....

Php – How to password protect streaming videos with php

Both nginx and lighttpd web servers have X-Send-File headers you can return from PHP. So you can do your checks in PHP and then conditionally server out the file.

if (check_user_can_access()){
    header('X-sendfile: /path/to/file');
} else {
    header('HTTP/1.1 403 Fail!');
}

Lighttpd also has a neat module called mod_secure_download that allows you to programatically generate a URL that will only be valid for a short time period.

Nginx, and possibly lighttpd, allow you to cap the download speed, so you're not sending out streaming data faster than it can be consumed.

Either way, you want to use your web server for serving files. Serving them through PHP is possible, but slow.

Best Answer

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How to do Flash pseudo-streaming

Php – How to password protect streaming videos with php

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