> I see that some of the TV modes do, indeed, allow the possibly of high > resolution 25fps with 320k aac. But say "or 90k". So I assume the 320k > would be fetched if available. (?)
Yes the default is to go for the highest sounds option linked available for the mode being downloaded. HVF modes are the only ones that support 320k bitrates. > This raises a more general question I'm unclear about. For some > resolutions, etc, various transfer modes are offerred. Given the > recent/current problems with hls this makes me wonder - is a specific > choice of transfer mode to be preferred when more than one nominally get > the same AV data? Or is this why the general terms like 'best' have a > particular ordering to try, so just adopting that approach always deals > with this question in terms of reliability and speed of fetching? RTMP is now not available through the most recent version of GiP and seemed to quite often time out during the download process and sometime damage the file in the process or restarting. HLS covers both HLS and HVF. Both download much faster than RTMP ever did and until recently were largely error free. HLS modes are processed completely by Akamai which is where we are currently seeing the segment missing errors again. HVF modes are processed by the BBC and then uploaded to the CDNs and are far more reliable than HLS as the BBC's processing system is designed specifically for the processing of BBC content for iPlayer. DASH is also fast but involves a bit more processing on your side to turn it into a playable file after download. It is downloaded as 2 files (audio and video) and then after downloading FFMPeg runs the 2 files together giving you a playable video. Probably the most reliable modes to use are the HVF options. The only reason I've really stuck with HLS is because, apart from Flash (RTMP) modes, HLS is the only option which supports 720p 25fps downloads. There is no equivalent option in DASH or HVF. As most of the HLS modes are now broken, I am using the HVF as a fallback when HLSHD does fail (which is most times) but because of the double size of HVFHD because it's 50fps, I am currently settling for HVFSD which is 540p 50fps which equals roughly the same bitrate and filesize of the old 720p 25fps HD downloads. _______________________________________________ get_iplayer mailing list get_iplayer@lists.infradead.org http://lists.infradead.org/mailman/listinfo/get_iplayer
