Goober5000: categorize

2009-10-30T02:23:41Z

categorize

← Older revision		Revision as of 02:23, 30 October 2009
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	Note to this source: the header must be loaded into the structure anifile.header. The image data must then be loaded into memory and available at pointer char *cf. The bitmap data is then loaded into anifile.frames[i].buffer.		Note to this source: the header must be loaded into the structure anifile.header. The image data must then be loaded into memory and available at pointer char *cf. The bitmap data is then loaded into anifile.frames[i].buffer.

			[[Category:File Types]]

Goober5000: moved ANI Formal Definition to ANI formal definition: wiki format for titles

2009-10-30T02:22:42Z

moved ANI Formal Definition to ANI formal definition: wiki format for titles

← Older revision	Revision as of 02:22, 30 October 2009
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Goober5000: capitalization

2009-10-30T02:22:28Z

capitalization

← Older revision		Revision as of 02:22, 30 October 2009
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	This information is copied from the ~~DEscent~~ Developer's Network [http://web.archive.org/web/20010619181602/descent-freespace.com/ddn/specs/ani/ Ani specs page]		This information is copied from the Descent Developer's Network [http://web.archive.org/web/20010619181602/descent-freespace.com/ddn/specs/ani/ Ani specs page]

	==Introduction==		==Introduction==

The E: Even more info from the DDN

2009-10-29T14:18:59Z

Even more info from the DDN

New page

This information is copied from the DEscent Developer's Network [http://web.archive.org/web/20010619181602/descent-freespace.com/ddn/specs/ani/ Ani specs page]

==Introduction==
The ANI file format is similar to the 256-color-PCX compression. It was however improved to provide transparent pixels as well as of course multiple images that make together the ANImation. All original ANI files are in FREESPACE.VP in Conflict, Descent: FreeSpace. In FreeSpace 2 they have been divided over several VP files.

This document was written by Heiko Herrmann with help by John Slagel of Volition Inc. (header information) and Garry Knudson (image data).

==File format==
The file begins with a fixed-size header and a variable number of keyframe definitions:

<pre>//Definitions
typedef struct ani_header
{
short should_be_zero; // always 0
short version; // >= 2
short fps; // played with <fps> frames per second
pal rgb; // ?
short w,h; // width, height
short nframes; // number of frames
char packer_code; // code used for compressed (repeated) bytes
pal palette[256]; // rgb-palette
short num_keys; // ?
} ani_header;

typedef struct ani_key
{
short twobyte;
short startcount;
} ani_key;

//File format
ani_header anifile.header;
for(i=0; i<anifile.header.num_keys; i++)
ani_key anifile.key[i];
int anifile.endcount;
</pre>
A keyframe is a frame that is provided *as is*, that means with no transparent pixels. So drawing that frame is not dependant of having the data from the previous frame (which is needed for transparent pixels). Usually ANImations have only one keyframe (the initial image = frame no.1). Some have more This is used for the following purposes:

The main hall ANImations have only key frames so that they can be played backwards (when moving the mouse away from a room in the main hall).
The weapon/ship ANImations have 2 (one additional) key frames: the second is the so-called "loop point": everything before is the animation how the weapon/ship appears in the briefings screen, everything after is the part that loops endless - the rotation.
The header is followed by the actual image data, as discussed below.

==Image data==
To understand the image data format, I chose to provide some code here:

<pre>
// ANI reader example code
// Taken from Descent Manager ANIVIEW32 - an adaption of a code part of FSView
// Written by Garry Knudson and Heiko Herrmann
// Copyright 1998-2000 by Descent Network Team
//
// Note: the header must be loaded into the structure anifile.header.
// The image data must then be loaded into memory and available at pointer char *cf.
// The bitmap data is then loaded into anifile.frames[i].buffer

byte runvalue,runcount;
int cur,max;
byte *p,*p2;
byte flagbyte;

max=anifile.header.w;
if(anifile.header.w % 4!=0) { //Garry Knudson 9-23-99
max += (4-(anifile.header.w%4));
}
max=max * anifile.header.h;

byte *cur_frame=new byte[max];
byte *last_frame=new byte[max];

memset(last_frame,anifile.header.rgb.r+256*anifile.header.rgb.g+65536*anifile.header.rgb.b,max);

//Load frames
for (i=0;i<anifile.header.nframes;i++)
{
cf=readfrombuffer(cf,&flagbyte,1);
cur=0;

/*char x[256];
sprintf(x,"Frame %i: %i\n",i,anif->GetPosition());
OutputDebugString(x);*/

p=cur_frame;
if(i>0)
p2=last_frame; //for transparent pixels
else
p2=cur_frame;

int x0,y0;
runcount=0;
cur=0;
for(y0=0;y0<anifile.header.h;y0++)
{
for(x0=0;x0<anifile.header.w;x0++)
{
if (runcount>0)
{
runcount--;
}
else
{
cf=readfrombuffer(cf,&runvalue,1);
if(runvalue==anifile.header.packer_code)
{
cf=readfrombuffer(cf,&runcount,1);
if(runcount<2)
runvalue=anifile.header.packer_code;
else
cf=readfrombuffer(cf,&runvalue,1);
}
}
*p=runvalue;
if(runvalue==254) //if transparent pixel, then use the pixel from the last frame
*p=*p2;
p++; p2++; cur++;
}
if(anifile.header.w % 4!=0) { //Garry Knudson 9-23-99
p +=(4-(anifile.header.w%4));
p2 +=(4-(anifile.header.w%4));
cur +=(4-(anifile.header.w%4));
}
}

//Process frame
anifile.frames[i].buffer=new byte[max];
memcpy(last_frame,cur_frame,max);
memcpy(anifile.frames[i].buffer,cur_frame,max);
}

---------------

char *readfrombuffer(char *org,void *dest,int num)
{
memcpy(dest,org,num);
org+=num;
return org;
}</pre>

Note to this source: the header must be loaded into the structure anifile.header. The image data must then be loaded into memory and available at pointer char *cf. The bitmap data is then loaded into anifile.frames[i].buffer.

ANI formal definition - Revision history

Goober5000: categorize

Goober5000: moved ANI Formal Definition to ANI formal definition: wiki format for titles

Goober5000: capitalization

The E: Even more info from the DDN