RESOLVED INVALID23336
Netflix instant watch movies freeze ~every 5 seconds for 2 seconds 
https://bugs.webkit.org/show_bug.cgi?id=23336
Summary Netflix instant watch movies freeze ~every 5 seconds for 2 seconds
Cameo Wood
Reported 2009-01-14 18:02:41 PST
Netflix uses Silverlight to present drm streaming movies. When using netflix on safari, the picture freezes for about 2 seconds every 5 seconds. This does not happen when I play the same movie simultaneously on the same machine using firefox. I have tried uninstalling and reinstalling both safari and silverlight. Let me know if I can do any debugging to help!
Attachments
Sample during skipping (48.89 KB, text/plain)
2009-01-14 23:31 PST, Mark Rowe (bdash) 		no flags
Details
Sample of netflix movie during skipping. (585.27 KB, text/plain)
2009-01-14 23:42 PST, Cameo Wood 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Mark Rowe (bdash)
Comment 1 2009-01-14 23:04:58 PST
Someone in #webkit just reported seeing this problem too.
Mark Rowe (bdash)
Comment 2 2009-01-14 23:05:13 PST
<rdar://problem/6498224>
Mark Rowe (bdash)
Comment 3 2009-01-14 23:31:10 PST
Created attachment 26748 [details] Sample during skipping The user I was talking with in #webkit provided the following sample from during a time that the movie was skipping.
Mark Rowe (bdash)
Comment 4 2009-01-14 23:34:40 PST
According to the user, Netflix "constantly loads between 550-850KB and as soon as it finishes that it downloads a new chunk (seen in activity window)". The sample output shows the main thread attempting to send a new request and looking for a cached response in the CFNetwork disk cache. However, it is blocked on a background thread that looks to be writing data out to the disk cache.
Mark Rowe (bdash)
Comment 5 2009-01-14 23:37:14 PST
The user was able to temporarily resolve their problems by emptying Safari's cache. I suspect that their disk cache may have reached its maximum capacity, which caused subsequent attempts to write to the cache to first have to prune the cache. Cameo, I would suggest trying emptying your cache. If this also clears the problem up for you then I think it supports my analysis and this bug should be dealt with via Radar.
Cameo Wood
Comment 6 2009-01-14 23:42:59 PST
Created attachment 26749 [details] Sample of netflix movie during skipping.
Cameo Wood
Comment 7 2009-01-14 23:47:41 PST
Confirmed. Works when I clear my cache. Maciej suggest I might upload my cache when it's skipping - that useful to you?
Mark Rowe (bdash)
Comment 8 2009-01-14 23:58:31 PST
It's probably not necessary, and your cache is likely to have a lot of private data in it.
Mark Rowe (bdash)
Comment 9 2009-01-15 19:28:56 PST
Since this bug is in CFNetwork, a Mac OS X system framework, rather than in WebKit this bug will be handled in Radar. This bug will be closed as INVALID to indicate that the problem was found to be outside of WebKit. Thanks for the report!
Note You need to log in before you can comment on or make changes to this bug.