Monthly Archives: March 2006

HD-DVD Available In Japan

Today’s IMDb Studio Briefing contains a quick notice that Toshiba has started selling HD-DVD, but only in Japan at this point. The HD-XA1 is expected stateside within a month. Toshiba’s official press release on the new unit provides a lot of juicy technical details. Nice to know that it supports just about every kind of optical disc that came before it.

The player spec page contains scant mentions of a new HD-DVD-ROM computer drive. I have not seen anything new on about that new laptop that should be equipped with the new technology.

Blu-Ray Media Before Blu-Ray Players

Today’s IMDb Studio Briefing reports in “Sony To Release Hi-Def Movies — With No Players” that, well, Sony plans to release movies in Blu-ray format before — well before — players are available, as in, movies in May, players by November (optimistically). The most incomprehensible part is that I will probably be one of the first consumers to procure such a disc just because I just have to have a sample of every kind of multimedia out there. My biggest question is whether or not there will be computer drives capable of reading Blu-ray discs.

Bizarre ASM Construct Of The Day

Check out this piece of x86 ASM arcana:

  lea   edx, [edx+1]

What on earth? This appears to be functionally equivalent to:

  inc   edx

So, what, was the compiler/assembler or possibly the original coder just trying to show off with a single overachieving x86 instruction like lea? Actually, a closer analysis of the surrounding ASM instructions may reveal what is happening here:

  cmp   ebx, value
  mov   al, [edx]
  lea   edx, [edx+1]
  mov   [edi], al
  lea   edi, [edi+1]
  jz    address

The conditional branch at the end of the block depends on the flags set by the comparison at the start. Per my understanding, neither mov nor lea modify flags but inc probably would (I can never find a good x86 reference– that includes flag data– when I need one). Why not perform the comparison just before the conditional branch? Mine is not to question why. But I imagine that someone will comment that this is an obscure optimization trick for original Pentium machines or some such.