Friday, August 22, 2008

Nokia N95 Test: Comparing Qik and N95 Video Quality

It's been two weeks since I returned the Nokia 95 to Nokia/WOM World which had been on loan as a demo trial device. I had a month to test it out and out it through it's paces. Nokia/ WOM World offers trial devices to social media users interested in participating in their trial program. The N95 8GB North American version is like the regular N95 8GB with a 5MP Carl Zeiss lens camera with auto-focus, video recording and many other features. My mobile carrier is ATT so it was easy for me to drop in my SIM card and upgrade my current plan to unlimited data to test out the applications I was really interested in, which were live mobile streaming.

My overall impression is that the N95 is a great device for video and photos and applications like Qik, Flixwagon, Kyte and Livecastr, which were ones I tested. The install and set up for each application was easy. However, the browser was a little archaic and without a QWERTY keyboard made seemingly simple feats like typing a real challenge (and a pain.) While I tried all four of the live mobile streaming applications I have to say that Qik is my favorite and it's the focus this post on comparing the quality of the Qik to the N95 video recording.

For the test my friend Rich recorded two clips of me in a studio setting with professional lighting and proper acoustics. One video was streamed live to the Qik web site (which was later archived) and the other was recorded straight onto the N95 (and not streamed live.) Both videos were recorded at the highest settings available on the N95 and Qik (640x480, high quality, highest FPS (frames per second). What's unclear in this test is the encoding mode (1 or 2-pass VBR, CBR), keyframe placement, filter settings (contrast, brightness, gamma) and how they're encoded (as MPEG-4 Part 2 or H.263 or MPEG-4 Part 10 (AVC/H.264) and I admit this is not an apples to apples comparison since the two videos were compressed at different bit rates and audio frequencies.

3gp profile
Video codec: Apple MPEG4 Decompressor, 640 x 480, Millions
AMR Narrowband, Mono, 8.000 kHz
Frames per second: 14.88 FPS (average)
Data rate: 516.57 kbits/s

In the Studio from Larry Kless on Vimeo.

mp4 profile
Video codec: Apple MPEG4 Decompressor, 640 x 480, Millions
Audio: AAC, Mono, 48.000 kHz
Frames per second: 29.22 FPS (average)
Data rate: 2056.22 kbits/s

There's a noticeable difference in detail in the Qik .3gp and the N95 .mp4 videos. The 3gp has more compression rendering less detail compared to the mp4. Compression rates also affect the audio quality. You can also really hear the difference between the 8 kHz narrowband compression of the 3gp to the 48 kHz ACC compression of the mp4. I think the n95 microphone does do a good job picking up sound even though it faces away from your shooting subject and it is possible to insert an external microphone.

The real time playback (temporal quality) of both videos holds up and there's not much motion artifacting but there's visible blockiness, fuzzyiness and noise. While there's a fair amount of color accuracy with both, neither video could actually capture the detail in the herringbone pattern of my jacket which is actually not something you should wear for video. I also should have taken a tip from myself since I always tell clients with jackets to wear a solid color (no busy patterns), fix their shirt collars, pull on their coat tails and sit on them to smooth out the shoulder line. I probably should have applied some make up too to cut out some of the shine. I'll keep those tips in mind for next time. ;-)