Follow Slashdot stories on Twitter


Forgot your password?

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).


Comment: Re:Good, Fast and Cheap... Pick Any Two (Score 5, Insightful) 101

by Cesare Ferrari (#46315481) Attached to: FFmpeg's VP9 Decoder Faster Than Google's

My understanding is that there is no room for decode artifacts in this - you either do it right, or it's not a proper decoder. This is a proper decoder, so will produce identical output to the google standard one. I believe there are test streams with md5s for the test frames, and this decoder passes the tests.

So, it's free, and it's correct, and it's fast. I think you have pre-conceived prejudices which are in this case wrong ;-)

From my perspective, faster is good for low power devices, so if this helps spread decent video codecs to more devices, that's a win.

Comment: Possible reasons (Score 1) 509

Maybe he doesn't like concurrent code because he's been bitten by nasty bugs enough times to shy away from it. Maybe he doesn't like your source control system as he has lost heaps of work in the past trusting it to a dodgy system. Maybe he has found code reviews a waste of time, or had bad experiences with pitched battles in a meeting room. Why don't you try asking him rather than speculating? 'Hey bob, it looks to me like you aren't keen on code reviews - why is that?' would be a good start.

Alternatively, he's a bit of a jerk, or bad at his job, and i'll leave that to you to figure out for yourself.

Comment: Re:Profit & Lies (Score 1) 730

by Cesare Ferrari (#39178519) Attached to: YouTube Identifies Birdsong As Copyrighted Music
Thanks for taking the time to try and spread some info about what has happened. It's amazing how unreasonable posters are being about this - you've already said the system failed, you have corrected the mistake and are trying to stop it happening again. Obviously people here have never produced software or a process with an error in it right ? ;-)

Comment: Re:Futile (Score 1) 160

by Cesare Ferrari (#39086085) Attached to: Book Review: Java Performance
Not my experience. I'm continually impressed with how fast java and C# are, and how well systems written in these languages perform in realtime apps. Sure, you get outliers, but then you get outliers from the OS, core swaps, networking stacks, etc etc, it's just one more area you have to watch and carefully consider, that's all. I'm not suggesting that code which hasn't been thought about performs well in this environment, but that it's possible to produce perfectly functional realtime systems with these languages.

Comment: I've seen how they do this at the cinema.. (Score 1) 612

by Cesare Ferrari (#38312500) Attached to: Iranian TV Shows Downed US Drone
The clever but somewhat unorthodox hacker employed by the Iranians pulls out his Apple Laptop and types furiously at a constant rate into a window with unrelated scrolling green text. A modal dialog box appears with a progress bar slowly ramping up to 100% and the text 'Sending virus to enemy drone'. He sits back looking smug with his hands behind his head. Once 100% is achieved, he again types furiously whilst explaining to the general standing behind him that he is going to send a surprise to the american scum operators. The drone sends out some sort of pulse of energy back up the channels being used to control it, and the equipment the american scum operators are using explodes in a shower of sparks and electrical discharges, frying the operators. The hacker than pushes a single button and the drone lands on a convenient long empty road. Everyone cheers. The hacker gets the girl.

Comment: Primo Levi (Score 1) 312

by Cesare Ferrari (#38263508) Attached to: Institutional Memory and Reverse Smuggling
I seem to remember Primo Levi wrote on this subject - not sure which of his books i've read, but something about a paint factory process springs to mind. Companies do loose information - it's entropy at work. It costs to keep information intact, and unfortunately there is much information and little indication of what may be important in the future.

Comment: Re:Lenses are going to be a problem (Score 1) 209

by Cesare Ferrari (#33464384) Attached to: Canon Develops 8 X 8 Inch Digital CMOS Sensor

Because CMOS sensors can't reset quickly. Why do you think any DSLR has a shutter? If they could do without they would have removed them. Although the name suggests the technology is digital, in actual fact digital sensors use good old analog techniques to capture charge based on light falling on the sensor. This is the bit which can't be reset (drained away) quickly enough when light is still falling on the sensor. The shutter really gives a black time when you can dump charge and reset things before allowing light to build up further charge.

I believe CCD sensors can be more quickly flushed of charge, but it's still not quick enough to do without a shutter. The benefits to a DSLR of not having a shutter would be to be able to sync flash at any shutter speed. This is one area where leaf shutters are good compared to focal plane shutters (as appear on DSLRs). Hasselblad made leaf and focal plane shutter cameras, and the abilty to use the leaf lenses on the focal plane shutter cameras to give more flexibilty on flash sync.

Comment: Lenses are going to be a problem (Score 1) 209

by Cesare Ferrari (#33461772) Attached to: Canon Develops 8 X 8 Inch Digital CMOS Sensor

Lenses which cover 8*8 are basically large format lenses which include leaf shutters. Leaf shutters have a couple of problems - limited size, and a limited upper speed. Typically 1/500th is the fastest a leaf shutter will operate, and the limited diameter means you typically are down to f5.6 or f8 as a maximum aperture.

The maximum aperture will limit the speed advantage against a 35mm DSLR or medium format where f/2 and faster is common (f/1 can be achived at standard lengths if you compromise on image quality, say a noctilux). f/1 vs f/5.6 is 5 stops, or 32 times the amount of light. So an f/1 lens vs an f/5.6 will accept 32 times as much light to start with

The usual complaint about fast lenses is the limited depth of field. However, large format at f/5.6 will also suffer this problem as the larger image format will also offer a limited DOF, but in addition, a slow lens. I guess the answer will be to run the sensor at a higher ISO equivalent, make it more sensitive, and hence allow a smaller aperture to be used, but the tradeoff isn't obvious from the specifications

My guess is that this is a technology demonstrator, and will not be available to average punters on real cameras. Saying that an old large format camera with a 8*8 back would be very cool

A committee is a group that keeps the minutes and loses hours. -- Milton Berle