opening mp4 via php results in full download before playback

问题

I'm trying to feed an mp4 file to flash player via php and the video is downloaded completely before starting playback.

$src = '/var/www/user/data/www/domain.com/video.mp4';
if(file_exists($src) and is_readable($src)) {
    header('Content-Type: video/mp4');
    header('Content-Length: '.filesize($src));
    readfile($src);
} else die('error');

I've tried curl with similar results. Any ideas what's causing this delay?

回答1:

Most likely your Flash player is hoping you'll handle HTTP Range requests so it can get started faster on the playback.

The HTML5/Flash audio player jPlayer has a section in their developer guide about this. Scroll to the part about Byte-Range Requests:

Your server must enable Range requests. This is easy to check for by seeing if your server's response includes the Accept-Ranges in its header.

Also note that they offer a PHP solution for handling Range requests if you have to use PHP instead of a direct download.

smartReadFile.php
https://groups.google.com/forum/#!msg/jplayer/nSM2UmnSKKA/bC-l3k0pCPMJ

回答2:

Another option would be to just have apache send the file it self as opposed to reading it in php and dumping it to the output using X-Sendfile.

First make sure apache is compiled with sendfile support then alter your output code to be:

header ('X-Sendfile: ' . $src);
header ('Content-Type:  video/mp4');
header ('Content-Disposition: attachment; filename="' . $filename . '"');
exit;

This is normally faster than doing it via PHP.

来源：https://stackoverflow.com/questions/12695586/opening-mp4-via-php-results-in-full-download-before-playback