Camera Nitty Gritty: Investigating video capture quality on Nokia's new devices

[slitchfield]

... In which I get all picky about the quality of video capture on Nokia's latest devices, the N79, N85 and (here) the N96. Is there a problem, and if so then is it down to changed premises, settings or lack of graphics acceleration hardware? For once, I'm really not sure and would love folk with more technical/photographic expertise than me to help out in the comments, as we try to get to the bottom of the issues.

Read on in the full article.

[Jaggz]

Good post.

I'll be honest, video capture on Nseries devices has been effectively in stasis since late 2006. If I didn't know any better (and I don't!), I'd say that it's probably that same old bit of code that was included with the original N93 firmware and the differences are purely down to lens/sensor configurations.

Back in August 2006, If someone had told me that in January 2009 video capture on the very latest Nokia's was about the same, I'd have laughed at their ignorance. Guess I'm the fool for believing that the N93 was the start of something special.

*sigh* I remember a time when Nokia cared more about video capture than 'So Lo'... Looks like those days are gone forever. Time to jump ship perhaps? Does Nokia ever finish anything off properly these days?

James @ Nokia Creative

[snoyt]

There is so much happening in mp4 compression that it is not really practical to simply compare two random single images side by side. A more in-depth statistical analysis taking the temporal character of mp4 compression would be required. Mpjeg could be compared in such a way.

In a mpeg4 stream there are full jpeg (actually dct I believe) every certain time period, and the time between them is filled with deltaframes using some form of motion compensation for further data reduction. The lossy compression as such is thus very dependent on the prestate of the stream and the input data. Thus when recording exactly the same image, but at different moments, results will vary. Throw in some automagical image contrast, colorbalans and brightness and things get rather fuzzy.

If there is someone working on mp4 compression and has some analysistools to check out the output stream and might even knows how to generate fake input data for the Nokia's. You might get some fancy and reliable numbers.

And my first N95 firmware actually retained it's photofocus from the camera mode onto the video mode. Which was irritating if I forgot. But heaven when I used it properly. I guess that's why they 'fixed' it. The Nokia's are meant for snapshots. And I guess AF does not work well enough for on-the fly video, occasionally it still goes occasionally off skilter for photo's. A visual check seems still neccesary.

"Or perhaps the distant photo test was a red herring and quality's almost always better on the N82 (and N95 etc) because of the extra graphics acceleration hardware helping out?"

Nope. The "extra graphics acceleration" in N82 and N95 is for 3D. It won't help with 2D graphics (video, photographs) at all.

N96 actually has better hardware support for 2D imaging than N95/N82. For video, N96 supports H.264, WMV and MPEG4 on hardware (whereas N95/N82 has hardware acceleration only for mpeg4). N96 also more advanced DSP support. I think your guess about different focusing range is propably correct, hard to say whetever it is intended or 'bug'.

On a more general level, I would say that phone photgraphy has sort of reached it's sweetspot. It's really hard to fit better optics on phones than what N95 and equavalent phones have. Throwing in sensor with more pixels won't help. Software has been pretty much optimized for that level as far possible. Only way forward on software side would mean 'Kodak moments' by 'photoshopping' pictures prettier instead better. Better lenses won't fit into mobile phones unless physical laws governing photons somehow change, and those haven't canged since few milliseconds after the Big Bang. Just compare SLR from 80's and DSLR form '08, and you see what I mean. They might have otherwise very different technology inside, but the optics haven't changed at all.

N93 tried packed some extra room for lenses and zoom with it's strange form factor. I guess problem with robustness of that form, and possibly appeal to customers, made them to abandon the idea.

[snoyt]

Originally Posted by Unregistered

"N96 actually has better hardware support for 2D imaging than N95/N82. For video, N96 supports H.264, WMV and MPEG4 on hardware (whereas N95/N82 has hardware acceleration only for mpeg4).

De MP4 is not a symmetrical algorithm. Decompression has very little to do with compression.

Originally Posted by Unregistered

On a more general level, I would say that phone photgraphy has sort of reached it's sweetspot. It's really hard to fit better optics on phones than what N95 and equavalent phones have. Throwing in sensor with more pixels won't help. Software has been pretty much optimized for that level as far possible. ... Better lenses won't fit into mobile phones unless physical laws governing photons somehow change, and those haven't canged since few milliseconds after the Big Bang.

For snapshots, the Nokia 5Mpixel resolution is pretty balanced for its price/quality. Better lenses and sensors do fit in a mobile phone. Liquid based lenses and other strategy are yet unexplored. Both (lenses and sensors) could improve the imagequality at 5 Mpixels. Optical zoom is unlikely to be introduced unless liquid lenses are used, which is yet unproven technology.

[alsiladka]

Steve,
In many of the comparisons online, the N85 performed better than the N96. It would have been better had you used the N85 against the N82.

I have no knowledge of the technical details, so i won't comment on the technical aspects of the comparisons, but according to what we have seen in the history of N Series, the quality of the camera's output has improved with the various FW updates offered by Nokia. So i would like to be biased and say that the camera performance would improve over the time.

[Kazutoyo]

Originally Posted by Unregistered

"Or perhaps the distant photo test was a red herring and quality's almost always better on the N82 (and N95 etc) because of the extra graphics acceleration hardware helping out?"

Nope. The "extra graphics acceleration" in N82 and N95 is for 3D. It won't help with 2D graphics (video, photographs) at all.

The OMAP 2420 platform (which N82 & N95 use) have two "graphic acceleration" chips. The PowerVR MBX chip for 3D acceleration and the IVA chip for imaging and video acceleration.

[NickAnstee]

Steve, have you tried recording the Video to a Micro SD Card instead of the Mass Storage Memory? Nick

[slitchfield]

Nick, will do. Do you have any observations in this department then? I don't think the issue is one of bitrate, this seems more a 'setting initial focus' bug....

I should confess I switched to an iPhone, but that was more because I wanted to escape 3 and it actually offered an interesting package.

Voice recording, I have about 3 apps which can do it
Radio - well, I love the last fm app
Experience - this is an odd one, with the years of experience nokia has you would expect them to be BETTER in the market than they are...
Camera - honestly, if only it had a flash and video it would be fine as it is ... but yeah, I have a sprog on the way and would think that crap video 'clips' would mean a huge amount to me!

My belief is that the iPhone is the kick that Nokia has needed, but I am not going back to a Nokia device for another 12 months - then I think it might be time to give them a try (or maybe Android).

G

Someone delete the previous post, it was meant for a different thread!!!

There definitly been a change in the size of the lens. I took a look at my n85 to my n95, theres been a slight change in size.
Another factor they have slimmed the newer devices, limiting the space more between the optic lens. rule of thumb, thicker better( i probably learned that here )

My n85, compared to my n95-1 is very poor. in pictures. images do seem poor at a near focual point, but i havent givin it a shot over distance.