WarpPNG.datatype 44.2 (9.1.2000)

The fastest 24-bit JPEG picture datatype! (for WarpUP PPC systems only)

Download WarpPNGdt.lha (44K)

WarpPNG.datatype is a yet another PNG datatype. The difference is that this is for owners of PPC cards, and it has been targetted specifically at WarpUp (not PowerUp). Even better, it is compact, clean, free and well behaved - a true plug'n'play PPC datatype.
I decided to write this datatype because no other decent WarpOS native PNG datatype exists for the PPC, and it is was relatively easy to implement being based on the same engine that WarpJPEG.datatype uses.
Changes since 44.1:

When the OS3.5 picture.datatype is in use, dithering is now switched off (only) if the image is to be rendered to a hi/true colour screen, resulting in much higher performance, with negligable quality loss.
Dispatcher now performs some extra functions, which should quash possible stability problems.

Speed

WarpPNG is currently the fastest PNG datatype available. The table below shows the time (in seconds) it took to decode 14 different images on my A1200 603e/240MHz 060/50MHz, with BVision and CGX picture.datatype, with other tested datatypes configured as close as possible to WarpPNG's internal settings:

PowerPC M68K

WarpPNG akPNG 44.65 PNGdt

44.2 WarpUp 68K G.Nikl

1024x768 24-bit colour, 833721 bytes 1.36 1.94 5.01 3.75

1024x768 24-bit colour, interlaced, 1037008 bytes 2.05 2.69 10.02 6.22

779x767 24-bit colour, 946564 bytes 1.19 1.76 4.83 3.33

473x639 24-bit colour, 377518 bytes 0.57 0.88 2.02 1.49

473x639 24-bit colour, interlaced, 459869 bytes 0.82 1.19 4.08 2.52

368x463 24-bit colour, 279896 bytes 0.38 0.65 1.61 1.02

251x400 24-bit colour, 136856 bytes 0.25 0.46 0.97 0.59

718x425 8-bit grey, 157890 bytes 0.27 0.53 1.27 0.71

718x425 8-bit grey, interlaced, 182522 bytes 0.38 0.75 3.33 1.39

1024x768 256 colours, 324599 bytes 0.43 0.76 1.62 0.93

779x767 256 colours, 404245 bytes 0.42 0.77 1.96 0.95

473x639 256 colours, 163397 bytes 0.24 0.49 0.98 0.49

368x463 256 colours, 115942 bytes 0.16 0.31 0.64 0.33

251x400 256 colours, 57056 bytes 0.11 0.38 0.46 0.20

	PowerPC	M68K
WarpPNG	akPNG 44.65	PNGdt
44.2	WarpUp	68K	G.Nikl
1024x768 24-bit colour, 833721 bytes	1.36	1.94	5.01	3.75
1024x768 24-bit colour, interlaced, 1037008 bytes	2.05	2.69	10.02	6.22
779x767 24-bit colour, 946564 bytes	1.19	1.76	4.83	3.33
473x639 24-bit colour, 377518 bytes	0.57	0.88	2.02	1.49
473x639 24-bit colour, interlaced, 459869 bytes	0.82	1.19	4.08	2.52
368x463 24-bit colour, 279896 bytes	0.38	0.65	1.61	1.02
251x400 24-bit colour, 136856 bytes	0.25	0.46	0.97	0.59
718x425 8-bit grey, 157890 bytes	0.27	0.53	1.27	0.71
718x425 8-bit grey, interlaced, 182522 bytes	0.38	0.75	3.33	1.39
1024x768 256 colours, 324599 bytes	0.43	0.76	1.62	0.93
779x767 256 colours, 404245 bytes	0.42	0.77	1.96	0.95
473x639 256 colours, 163397 bytes	0.24	0.49	0.98	0.49
368x463 256 colours, 115942 bytes	0.16	0.31	0.64	0.33
251x400 256 colours, 57056 bytes	0.11	0.38	0.46	0.20

These figures are provided for comparison purposes only, but they speak for themselves... WarpPNG is at least 50% faster than the native WarpOS version of akPNG in most cases (80-300% faster with palette based and/or smaller files), and around 3 times faster than 68k datatypes on a 060 (the speed difference will be even greater on 040 systems with a fast PPC). All this and no loss in image quality! All tests were performed, multiple times, using Visage, with the following command line: "visage test.png nopng time test".

Requirements

PPC accelerator card + 68040/060
WarpUp Release 4 (powerpc.library V15) or higher
picture.datatype v43 or higher (i.e. either of the ones supplied with AmigaOS 3.5, P96 or CGraphX)
Kickstart 3.0 or higher

Note that a graphics card is not necessary - the P96 or OS 3.5 picture.datatype will automatically dither images down to your display requirements.

Back to my homepage

Last modified: Sun Jan 09 19:04:15 2000