On 16/04/2018 2:18 AM, RS wrote: > A couple of years ago there were problems with HLS and there was > speculation that we might have 50 fps HVFhd and DVFhd as the only HD > modes. At that time I wondered if it would be feasible to drop every > other frame to reduce the frame rte to 25 fps. I thought because of > the H.264 delta encoding it would probably mean transcoding and that > it would be too slow. > > On a 42" screen for the programmes that I usually watch I cannot see > any difference between a HD picture at 50 fps and one at 25 fps, so 50 > fps for me is just a waste of bandwidth and storage space, so I have > been looking at it again.
I experimented a while ago with running some GiP downloads through Handbrake to convert the video to the x265 codec. That reduced the file size to about 1/3 of the original download, with no subjective difference in video quality that I could see when viewing on our TV. A one hour 1280x720 25fps program that downloads as a 1Gb file was reduced in size to ~350Mb. On my PC, the re-encode runs at about 50fps for 1280x720, so ~2x real time for 25fps and ~real time for 50fps. For smaller video dimension such as 960x540, the re-encode speed was around 85-90FPS. Nick _______________________________________________ get_iplayer mailing list firstname.lastname@example.org http://lists.infradead.org/mailman/listinfo/get_iplayer