I`ve looked for a similar question but there are so many posts that I thought it would be quicker to just ask.

When fast forwarding an HD recording it seems to really whizzy through it much faster than an SD recording. I take it there`s a technical reason for this. Maybe Graham or Gaseous or anyone really could offer an explanation. Is some kind of compression used to cram the extra HD signal onto the hard drive? Saying that the HD recordings take up much more space apparently.

On a Foxsat HDR, you should have the usual 2x, 4x, 16x, 32x, 64x options, same as SD.
I have not noticed any difference to SD behaviour in the 18 months I have been using mine....

HD recordings are compressed using a more efficient and modern encoding technique called H264 (a variant of mpeg4). SD use the older mpeg2 system. Even with more efficient codeing the large amount of additional video data for HD requires more disc space. As said though fast forward is just the same as for SD.

I hardly ever use fast forward anyway, the +2min and -15Sec forward and reverse skip buttons are much more convenient for ad-skipping and if you want to go a long way just tap in the timecode you want eg 0025 will take you straight to 25 mins.

Maybe you're experiencing some optical illusion that gives the impression of a faster transport through the recorded HD media. As tv-Addict says the speeds are the same on SD and HD and Graham points to the fact that more disc space is required to store the data. When transporting through the video stream it could be that as it samples sections of data to output to the display there is a greater amount of data per sample and so the spaces between each sample need to be increased as the read time for each sample would be longer and thus resulting in a more frenetic display output giving the impression that it's 'whizzing' through faster.

Many thanks for your replies guys. Must be an optical illusion as you say. It`s not just that I can barely keep up with the image even at only 4X but the ads seem to end far quicker than with SD. The ad breaks appear to last approximately the same length of time so maybe I`ve got a special box.

I`ve never used the skip forward facility mainly because I wasn`t aware of it. Ive only had it for 18 months though and still trying to figure out all the functions.

Cheers fellas.

Use the skip, its much better, especially for ads. I only use the FF if Im catching up on a game and use x4 until they get into the final 3rd.

Same here. Something I really wish Sky would add to their boxes.

Which, the skipping or variable FF?

I have been aware of this since ITV HD started. Their programs fast forward about 4x faster than indicated. So an ITV HD recording on 16x FF will take about 50 to 60 seconds to advance an hour, whereas a SD recording takes about 4 minutes to do the same.

Before their encoder change BBC HD recordings fast forwarded as indicated on the Humax's display. Since the new encoder was introduced however they have speeded up, but not to the same extent as ITV HD.

Well, I am also experiencing the same "optical illusion".
So much so that I am convinced that the FF/RW speeds are genuinely much faster than they should be for HD recordings.

I normally FF through the ads at 16x on SD recordings but can only excercise proper control at x4 on HD recordings.

Frank

Skipping. FF is a pain.

It's easy enough to prove.

FF 16x for 1 minute. On SD recordings you will advance to 0.16. on ITV HD its around 1 hour, & BBC HD 20 to 35 minutes.

Thats because they want you to see the ads.

I can confirm the FF is a lot faster on ITVHD too.