Connected TV

Some fascinating research into viewer reactions to HDTV has been unveiled today by the French transmission company TDF, which appears to show that HD versions of TV broadcasts can add value to standard-definition ones in a wide variety of ways.

The study was carried out by the Lutin user lab between the months of September and November, and largely predated the launch of HDTV on the French DTT platform.

The set-up of the experiments involved respondents being wired up and recorded during two different viewing scenarios: in the first, they watched SD and HD versions of the same content being broadcast simultaneously on two identical adjacent HD-Ready flat-screen displays for ten minutes; in the second, they were asked to choose with a remote control and watch SD or HD programming from a selection offering content divided 50/50 between the two modes.

The full version of the results (French readers only, I’m afraid) can be found here. Meanwhile, here are some of the highlights:

• In the first scenario, when the same content could be watched either in SD or HD over a ten-minute period, respondents spent 70% of the ten-minute period watching HD. 77% of them said they preferred HD; and 76% of them found that the quality of the HD picture was better.
• In the second scenario, when respondents were free to hop between different content modes as they saw fit, they spent 25% more time watching HD content before switching to a different channel. On average, they also chose HD programming 12.5% more than SD versions of the same programmes.

Physiological monitoring of the test subjects, combined with questionnaires, also found that HD both increased the legibility of, and the amount of ‘reading’ of the images, increasing comprehension of what was being shown, and stimulating viewers’ curiosity and imagination.

A few comments: first, although the results seem impressive, it’s striking that roughly a quarter of the guinea-pigs did not prefer watching HD and did not find the quality superior. Interestingly, these results bear out qualitative research commissioned by the UK regulator, Ofcom, a year ago, using similar side-by-side tests. This concluded that “Participants […] held mixed views as to the consumer value of HDTV. Some liked it a great deal for its improved picture quality, while others were less impressed.”

Second, it is also, on the face of it, surprising that when presented with HD and SD versions of the same content, the HD versions only get chosen 12.5% more. This may signal either that consumers need more education about the differences between HD and SD content, or - more likely - that it is problematic to locate the HD version, because it resides on a channel somewhere else on the EPG.

Lastly, it’s a pity the tests did not compare live off-air HD DTT content with equivalent SD versions, because there have been some suggestions that the average bit-rate per MPEG-4 HD video-stream of 7MBit/s on the French HD DTT multiplex is on the low side, and could impact quality.

In the event, Lutin used pre-recorded HD and SD video streams across a variety of genres lent to them by two of the French commercial terrestrial networks, TF1 and M6. Unfortunately, the TDF research, as published, does not reveal their respective encoding rates, or whether these recordings were the result of on-the-fly encoding or multiple offline ‘passes’. Such details would have provided the research with a good deal more credibility.

For broadcasters, however, the mere fact that consumers appear to spend longer watching HD programmes and find them more ‘sticky’, and have some preference for HD over SD versions, is probably significant enough.

As TDF puts it, HDTV offers them a “new universe of opportunity”, because it “opens up a new televisual and narrative space, increases the attractiveness of content and viewing-time, and limits channel-hopping.”