ximagif.cpp

ddrawCximage 简单的可以用directshow 显示各种图片的小程序 。在ARMV4I平台运行通过。

		if (fp->Read(&ch, sizeof(ch), 1) != 1) {break;}

		if (bPreviousWasNull || ch==0)
		{
			switch (ch)
			{
			case '!': // extension
				{
				DecodeExtension(fp);
				break;
				}
			case ',': // image
				{

				assert(sizeof(image) == 9);
				//log << "Image header" << endl;
				fp->Read(&image,sizeof(image),1);

				//avoid byte order problems with Solaris <candan> <AMSN>
				image.l = ntohs(image.l);
				image.t = ntohs(image.t);
				image.w = ntohs(image.w);
				image.h = ntohs(image.h);

				// in case of images with empty screen descriptor, give a last chance
				if (dscgif->scrwidth==0 && dscgif->scrheight==0){
					dscgif->scrwidth = image.w;
					dscgif->scrheight = image.h;
				}

				if (((image.l + image.w) > dscgif->scrwidth)||((image.t + image.h) > dscgif->scrheight))
					break;

				nframes++;

				// Local colour map?
				if (image.pf & 0x80) {
					TempTabCol.sogct = (short)(1 << ((image.pf & 0x07) +1));
					assert(3 == sizeof(struct rgb_color));
					fp->Read(TempTabCol.paleta,sizeof(struct rgb_color)*TempTabCol.sogct,1);
					//log << "Local colour map" << endl;
				}

				int badcode=0;
				ibf = GIFBUFTAM+1;

				interlaced = image.pf & 0x40;
				iheight = image.h;
				istep = 8;
				iypos = 0;
				ipass = 0;

				long pos_start = fp->Tell();

				//if (interlaced) log << "Interlaced" << endl;
				decoder(fp, 0, image.w, badcode);

				if (badcode){
					seek_next_image(fp,pos_start);
				} else {
					fp->Seek(-(ibfmax - ibf - 1), SEEK_CUR);
				}
		
				break;
				}
			case ';': //terminator
				bContinue=false;
				break;
			default:
				bPreviousWasNull = (ch==0);
				break;
			}
		}
	}

	fp->Seek(pos,SEEK_SET);
	return nframes;
}
////////////////////////////////////////////////////////////////////////////////
long CxImageGIF::seek_next_image(CxFile* fp, long position)
{
	fp->Seek(position, SEEK_SET);
	char ch1,ch2;
	ch1=ch2=0;
	while(fp->Read(&ch2,sizeof(char),1)>0){
		if (ch1 == 0 && ch2 == ','){
			fp->Seek(-1,SEEK_CUR);
			return fp->Tell();
		} else {
			ch1 = ch2;
		}
	}
	return -1;
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::SetLoops(int loops)
{	m_loops=loops; }
////////////////////////////////////////////////////////////////////////////////
long CxImageGIF::GetLoops()
{	return m_loops; }
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::SetComment(const char* sz_comment_in)
{	if (sz_comment_in) strncpy(m_comment,sz_comment_in,255); }
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::GetComment(char* sz_comment_out)
{	if (sz_comment_out) strncpy(sz_comment_out,m_comment,255); }
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::GifMix(CxImage & imgsrc2, struct_image & imgdesc)
{
	long ymin = max(0,(long)(GetHeight()-imgdesc.t - imgdesc.h));
	long ymax = GetHeight()-imgdesc.t;
	long xmin = imgdesc.l;
	long xmax = min(GetWidth(), (DWORD)(imgdesc.l + imgdesc.w));

	long ibg2= imgsrc2.GetTransIndex();
    BYTE i2;

	for(long y = ymin; y < ymax; y++){
		for(long x = xmin; x < xmax; x++){
			i2 = imgsrc2.GetPixelIndex(x-xmin,y-ymin);
			if(i2!=ibg2) SetPixelIndex(x,y,i2);
		}
	}
}
////////////////////////////////////////////////////////////////////////////////
/*-----------------------------------------------------------------------
 *
 * miGIF Compression - mouse and ivo's GIF-compatible compression
 *
 *          -run length encoding compression routines-
 *
 * Copyright (C) 1998 Hutchison Avenue Software Corporation
 *               http://www.hasc.com
 *               [e-mail]
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted, provided
 * that the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation.  This software is provided "AS IS." The Hutchison Avenue 
 * Software Corporation disclaims all warranties, either express or implied, 
 * including but not limited to implied warranties of merchantability and 
 * fitness for a particular purpose, with respect to this code and accompanying
 * documentation. 
 * 
 * The miGIF compression routines do not, strictly speaking, generate files 
 * conforming to the GIF spec, since the image data is not LZW-compressed 
 * (this is the point: in order to avoid transgression of the Unisys patent 
 * on the LZW algorithm.)  However, miGIF generates data streams that any 
 * reasonably sane LZW decompresser will decompress to what we want.
 *
 * miGIF compression uses run length encoding. It compresses horizontal runs 
 * of pixels of the same color. This type of compression gives good results
 * on images with many runs, for example images with lines, text and solid 
 * shapes on a solid-colored background. It gives little or no compression 
 * on images with few runs, for example digital or scanned photos.
 *
 *                               der Mouse
 *                      [e-mail]
 *            7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B
 *
 *                             [e-mail]
 *
 * The Graphics Interchange Format(c) is the Copyright property of
 * CompuServe Incorporated.  GIF(sm) is a Service Mark property of
 * CompuServe Incorporated.
 *
 */
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_clear(struct_RLE* rle)
{
	rle->out_bits = rle->out_bits_init;
	rle->out_bump = rle->out_bump_init;
	rle->out_clear = rle->out_clear_init;
	rle->out_count = 0;
	rle->rl_table_max = 0;
	rle->just_cleared = 1;
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_flush(struct_RLE* rle)
{
	if (rle->rl_count == 1){
		rle_output_plain(rle->rl_pixel,rle);
		rle->rl_count = 0;
		return;
	}
	if (rle->just_cleared){
		rle_flush_fromclear(rle->rl_count,rle);
	} else if ((rle->rl_table_max < 2) || (rle->rl_table_pixel != rle->rl_pixel)) {
		rle_flush_clearorrep(rle->rl_count,rle);
	} else {
		rle_flush_withtable(rle->rl_count,rle);
	}
	rle->rl_count = 0;
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_output_plain(int c,struct_RLE* rle)
{
	rle->just_cleared = 0;
	rle_output(c,rle);
	rle->out_count++;
	if (rle->out_count >= rle->out_bump){
		rle->out_bits ++;
		rle->out_bump += 1 << (rle->out_bits - 1);
	}
	if (rle->out_count >= rle->out_clear){
		rle_output(rle->code_clear,rle);
		rle_clear(rle);
	}
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_flush_fromclear(int count,struct_RLE* rle)
{
	int n;

	rle->out_clear = rle->max_ocodes;
	rle->rl_table_pixel = rle->rl_pixel;
	n = 1;
	while (count > 0){
		if (n == 1){
			rle->rl_table_max = 1;
			rle_output_plain(rle->rl_pixel,rle);
			count --;
		} else if (count >= n){
			rle->rl_table_max = n;
			rle_output_plain(rle->rl_basecode+n-2,rle);
			count -= n;
		} else if (count == 1){
			rle->rl_table_max ++;
			rle_output_plain(rle->rl_pixel,rle);
			count = 0;
		} else {
			rle->rl_table_max ++;
			rle_output_plain(rle->rl_basecode+count-2,rle);
			count = 0;
		}
		if (rle->out_count == 0) n = 1; else n ++;
	}
	rle_reset_out_clear(rle);
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_reset_out_clear(struct_RLE* rle)
{
	rle->out_clear = rle->out_clear_init;
	if (rle->out_count >= rle->out_clear){
		rle_output(rle->code_clear,rle);
		rle_clear(rle);
	}
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_flush_withtable(int count, struct_RLE* rle)
{
	int repmax;
	int repleft;
	int leftover;

	repmax = count / rle->rl_table_max;
	leftover = count % rle->rl_table_max;
	repleft = (leftover ? 1 : 0);
	if (rle->out_count+repmax+repleft > rle->max_ocodes){
		repmax = rle->max_ocodes - rle->out_count;
		leftover = count - (repmax * rle->rl_table_max);
		repleft = 1 + rle_compute_triangle_count(leftover,rle->max_ocodes);
	}
	if (1+rle_compute_triangle_count(count,rle->max_ocodes) < (unsigned int)(repmax+repleft)){
		rle_output(rle->code_clear,rle);
		rle_clear(rle);
		rle_flush_fromclear(count,rle);
		return;
	}
	rle->out_clear = rle->max_ocodes;
	for (;repmax>0;repmax--) rle_output_plain(rle->rl_basecode+rle->rl_table_max-2,rle);
	if (leftover){
		if (rle->just_cleared){
			rle_flush_fromclear(leftover,rle);
		} else if (leftover == 1){
			rle_output_plain(rle->rl_pixel,rle);
		} else {
			rle_output_plain(rle->rl_basecode+leftover-2,rle);
		}
	}
	rle_reset_out_clear(rle);
}
////////////////////////////////////////////////////////////////////////////////
unsigned int CxImageGIF::rle_compute_triangle_count(unsigned int count, unsigned int nrepcodes)
{
	unsigned int perrep;
	unsigned int cost;

	cost = 0;
	perrep = (nrepcodes * (nrepcodes+1)) / 2;
	while (count >= perrep){
		cost += nrepcodes;
		count -= perrep;
	}
	if (count > 0){
		unsigned int n;
		n = rle_isqrt(count);
		while ((n*(n+1)) >= 2*count) n --;
		while ((n*(n+1)) < 2*count) n ++;
		cost += n;
	}
	return(cost);
}
////////////////////////////////////////////////////////////////////////////////
unsigned int CxImageGIF::rle_isqrt(unsigned int x)
{
	unsigned int r;
	unsigned int v;

	if (x < 2) return(x);
	for (v=x,r=1;v;v>>=2,r<<=1) ;
	for( ;; )
	{
		v = ((x / r) + r) / 2;
		if ((v == r) || (v == r+1)) return(r);
		r = v;
	}
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_flush_clearorrep(int count, struct_RLE* rle)
{
	int withclr;
	withclr = 1 + rle_compute_triangle_count(count,rle->max_ocodes);
	if (withclr < count) {
		rle_output(rle->code_clear,rle);
		rle_clear(rle);
		rle_flush_fromclear(count,rle);
	} else {
		for (;count>0;count--) rle_output_plain(rle->rl_pixel,rle);
	}
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_write_block(struct_RLE* rle)
{
	g_outfile->PutC((BYTE)rle->oblen);
	g_outfile->Write(rle->oblock,1,rle->oblen);
	rle->oblen = 0;
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_block_out(unsigned char c, struct_RLE* rle)
{
	rle->oblock[rle->oblen++] = c;
	if (rle->oblen >= 255) rle_write_block(rle);
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_block_flush(struct_RLE* rle)
{
	if (rle->oblen > 0) rle_write_block(rle);
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_output(int val, struct_RLE* rle)
{
	rle->obuf |= val << rle->obits;
	rle->obits += rle->out_bits;
	while (rle->obits >= 8){
		rle_block_out((unsigned char)(rle->obuf&0xff),rle);
		rle->obuf >>= 8;
		rle->obits -= 8;
	}
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::rle_output_flush(struct_RLE* rle)
{
	 if (rle->obits > 0) rle_block_out((unsigned char)(rle->obuf),rle);
	 rle_block_flush(rle);
}
////////////////////////////////////////////////////////////////////////////////
void CxImageGIF::compressRLE( int init_bits, CxFile* outfile)
{
	g_init_bits = init_bits;
	g_outfile = outfile;

	struct_RLE rle;
	rle.code_clear = 1 << (init_bits - 1);
	rle.code_eof = rle.code_clear + 1;
	rle.rl_basecode = rle.code_eof + 1;
	rle.out_bump_init = (1 << (init_bits - 1)) - 1;
	rle.out_clear_init = (init_bits <= 3) ? 9 : (rle.out_bump_init-1);
	rle.out_bits_init = init_bits;
	rle.max_ocodes = (1 << MAXBITSCODES) - ((1 << (rle.out_bits_init - 1)) + 3);
	rle.rl_count = 0;
	rle_clear(&rle);
	rle.obuf = 0;
	rle.obits = 0;
	rle.oblen = 0;

	rle_output(rle.code_clear,&rle);

	int c;
	for( ;; )
	{
		c = GifNextPixel();
		if ((rle.rl_count > 0) && (c != rle.rl_pixel)) rle_flush(&rle);
		if (c == EOF) break;
		if (rle.rl_pixel == c){
			rle.rl_count++;
		} else {
			rle.rl_pixel = c;
			rle.rl_count = 1;
		}
	}
	rle_output(rle.code_eof,&rle);
	rle_output_flush(&rle);
}
////////////////////////////////////////////////////////////////////////////////
#endif // CXIMAGE_SUPPORT_GIF