On 25/01/2011 12:00 PM, scott wrote:
>> Also, it costs about 5x the price of this toy.
>
> "HD Hero 960" is only $180, which is only about 50% more than your camera.

OK, I didn't see that splashed across the front page.

Then again, I'll bet the big glossy video was shot with the flagship 
product. ;-)

>> Spec claims it comes with a 4 GB flash card, but that's going to fill in
>> seconds I would imagine.
>
> Spec also claims it fills a 32 GB card in 4 hr 21m. So with the 4 GB
> card I make that just over 30 mins. If it was me I'd buy a couple of
> 16GB cards, 2hr recording time per card seems pretty decent.

They make flash cards that big now? Mmm, interesting.

I'm still surprised that you can fit 30 minutes into 4 GB. My camcorder 
works with DVDs and it can handle less than 20 minutes, and that's only 
standard definition. (And with far more compression than I'd like too...)

>> I was under the impression that the compression algorithm remains the
>> same regardless of what bitrate you select.
>
> You want some options to play with? :-)
>
> http://mewiki.project357.com/wiki/X264_Settings

OK, so you can change the frequency weightings and how often a keyframe 
is put in, and so forth. I'm not seeing much that fundamentally changes 
the whole algorithm such that it might require less computer power.

> The only one I heard about was the motion estimation algorithm,
> obviously the better it can detect motion between frame the less bits
> are needed to get a certain quality level. But there seems to be a load
> more options to change stuff, in a battery powered device you would need
> to carefully consider how much of an impact each had on battery life.

I was thinking more the problem of "how can we encode this fast enough 
to be realtime?" It's not like the device has an Intel Xeon quad-core in 
there, is it. From what I've heard, H.264 is very hungry for computer 
power. (Although, as I say, I imagine the really hungry bits probably 
have custom hardware acceleration in a device like this.)

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