urisourcebin: Download-buffering trashes on fast network
When download-buffering is enabled in playbin (through the download
flag), accessing videos through HTTP will download the video as fast as possible, and write it to a local cache.
Unfortunately that means that it will try to download hundreds of megs of data from local DLNA server, with the local cache being slow enough that this will cause performance problems until the download has finished. Ideally, urisourcebin
/downloadbuffer
would know how fast the disk and the network are so it can throttle its own download speed.