dinkypumpkin at gmail.com
Wed Jun 13 18:20:33 EDT 2012
On 13/06/2012 21:18, Arthur Murray wrote:
> I was wondering what stco parsing is and if gzip should really still
> be disabled by default? The commented out line was added in 2009.
> I'd prefer to enable it to reduce download times and wasted internet
> bytes, and would prefer to solve the real problem if there is one. How
> can I test if this mystery "perl bug" still exists or if there is any
> downside to enabling it now in 2012? I've briefly tested while gzip
> was enabled and I didn't notice any problems.
> 1921 # Using this slows down stco parsing!!
> 1922 #$ua->default_header( 'Accept-Encoding', 'gzip,deflate' );
> 2522 # Only return decoded content if gzip is used - otherwise
> this severely slows down stco scanning! Perl bug?
I presume that "stco parsing" refers to accessing iPhone streams,
something get_iplayer used to do. The "stco" atom in an MP4 container
holds a lookup table for the actual data chunks in the file, for
seeking, etc. I can see how adding overhead for decompression could
slow things down. That iPhone-related code is still in get_iplayer, but
it's deadwood since the BBC locked down the iPhone streams a couple of
years ago. These days the only things get_iplayer itself downloads are
XML resources of one sort or another. rtmpdump (and mplayer for WMA)
handle all the streaming now. I don't know if enabling that
Accept-Encoding header will make much of a difference. If you can
quantify a significant speed-up with it, by all means submit a patch. I
would guess the best place to test timings is when doing full refreshes
of the cache.
More information about the get_iplayer