bvibber

; Round top 16 bits of 32-bit fixed-point number in-place with with the 17th bit down
; Note: does not shift! The top bits remain in the top two bytes.
;
; If 0 bit: 5 + 12 = 5 cycles
; If 1 bit: 5 + 5 + 21 + 3? = 28 cycles for positive, 31 for negative
;
; Average given even distribution of data:
; 5 / 2 + 28 / 4 + 31 / 4 = 2.5 + 7 + 7.75 = 17.25 cycles
;
; Note a 16-bit copy is:

bvibber

; Lightly tested work in progress; imul16 for 6502
; two 16-bit inputs, one 32-bit output
; using the Atari floating point registers as argument placeholders
; ca65 syntax 
; brion vibber, 2022

; FP registers in zero page
FR0 = $d4
FRE = $da
FR1 = $e0

bvibber

.PHONY : clean

borf : borf.c Makefile
	gcc -o borf -mf16c borf.c

clean :
	rm -f borf

bvibber

// Calculate ideal viewing distance such that
// in-game FOV matches angular size in player's
// vision.

// 34" 21:9 "ultrawide"
// approx 90-degree horizontal FOV in MSFS
distance({
    h_px: 3440,
    v_px: 1440,
    diagonal_in: 34,

bvibber

@rem Tone-map HDR game captures to SDR suitable for further processing or posting.
@rem Input file: something.mp4 (HEVC HDR 10-bit BT2020)
@rem Output file: something-sdr.mp4 (H.264 SDR 8-bit BT709)

ffmpeg -i "%~f1" ^
  -vf "zscale=t=linear:p=bt709,tonemap=hable,zscale=t=bt709:m=bt709:r=tv,format=yuv420p" ^
  -crf 12 ^
  -y "%~n1-sdr.mp4"

bvibber

Integer-indexed arrays:

This is an in-order binary tree, where the tree nodes directly contain the items.

The bigger an array gets, the slower lookups will get in it but they'll be fairly consistent for a given size. Iterating the tree is faster than individually looking up indexes in turn.

The array-bits is the number of "hash" bits used to traverse the tree with 16-bit integer index keys. The array-length is the highest index inserted so far plus one; when it exceeds 2^array-bits, add a layer to the tree and move the old tree into the left hand. Start traversals with the most significant bit within the hash size for proper ordering.

Note that the object exposes a string-indexed property tree too, here elided into a single property descriptor for length, which mirrors the internal 16-bit length with a JS number.

bvibber

diff --git a/resources/ext.tmh.OgvJsSupport.js b/resources/ext.tmh.OgvJsSupport.js
index 3ee84110..827ba16d 100644
--- a/resources/ext.tmh.OgvJsSupport.js
+++ b/resources/ext.tmh.OgvJsSupport.js
@@ -86,21 +86,28 @@
 			 * @return {boolean}
 			 */
 			isMediaNativelySupported: function ( mediaElement ) {
-				var mediaType;
 				var supportedNatively = false;

bvibber

; Note fixed addresses are illustrative, not real
.org $4000

; Zero page variables
scratch1 = $80
scratch2 = $82
freelist = $84 ; ref to next free node
gc_color = $86 ; current representation of "white" for tricolor marking

heap_start = $8000

bvibber

# currently broken in the 2-pass settings?

INFILE="$1"
FILE_HEIGHT=`ffprobe -hide_banner -show_entries stream=height -of csv=p=0:s=x "$INFILE"`

function ffmpeg() {
    LD_LIBRARY_PATH=/opt/ffmpeg/lib /opt/ffmpeg/bin/ffmpeg "$@"
}

function run() {

bvibber

    var key = true;

    switch ( key ){                           //  Earth

        case ( altitude <= 36152. ):          //  Altitude is in feet       // Troposphere
          temperature = 518.6 - 3.56 * ( altitude / 1000. );
          break;
        case ( altitude >= 36152. && altitude <= 82345. ):                  // Stratosphere
          temperature = 389.98;
          break;