Files
Sylpheed/docs
sylph-decoder 06c69b3143 re: PRE-REGISTER the guest frame-rate test -- the movie is the ruler
Units per second is the one number left on the PRESS (A) plate, and both
existing measurements of it are wall-clock readings off an emulator that
runs the guest slower than real time by an unknown factor. They disagree
by 2.9x, which is what that method is worth here.

ADV.wmv declares 30.0000 fps exactly in its own ASF header (stream #2,
avgTimePerFrame = 333333 x100ns). That is a disc fact, so a decoded movie
frame is a tick of a clock Canary's speed cannot stretch.

The measurement is a ratio of counts with no wall clock in it: how many
consecutive swap labels bind the same movie luma texture base.

  H_A  guest 30 fps ->  60 units/s -> 1.0 labels per movie frame
  H_B  guest 60 fps -> 120 units/s -> 2.0 labels per movie frame

Committed BEFORE the capture so the number cannot be chosen afterwards,
with acceptance bands, the three ways the instrument could lie, a guard
for two of them, and a named control (the splashes' established +34/frame
must reproduce in the same log, or the log is not comparable).

Noting the trap I nearly fell into: stream #1's avgTimePerFrame is a
packet rate and reads as 3.05 fps. Reading the wrong stream is the obvious
way to get this wrong, so it is written down.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t
2026-09-01 18:43:13 +00:00
..