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#include <stdlib.h>
#include "config.h"
#include "bswap.h"
#include "postproc/rgb2rgb.h"
#include "libvo/fastmemcpy.h"
#include "mp_msg.h"
#include "png.h"
static int pngPointer;
static void pngReadFN( png_structp pngstr,png_bytep buffer,png_size_t size )
{
char * p = pngstr->io_ptr;
memcpy( buffer,(char *)&p[pngPointer],size );
pngPointer+=size;
}
void decode_mpng(
unsigned char *encoded,
int encoded_size,
unsigned char *decoded,
int width,
int height,
int bytes_per_pixel)
{
png_structp png;
png_infop info;
png_infop endinfo;
png_bytep data;
png_bytep * row_p;
png_uint_32 png_width,png_height;
char * palette = NULL;
int depth,color;
png_uint_32 i;
/* currently supporting only 24 and 32bpp */
if ((bytes_per_pixel != 3) && (bytes_per_pixel != 4))
{
/* is this memset really needed? */
memset(decoded, 0, width*height*bytes_per_pixel);
return;
}
png=png_create_read_struct( PNG_LIBPNG_VER_STRING,NULL,NULL,NULL );
info=png_create_info_struct( png );
endinfo=png_create_info_struct( png );
pngPointer=8;
png_set_read_fn( png,encoded,pngReadFN );
png_set_sig_bytes( png,8 );
png_read_info( png,info );
png_get_IHDR( png,info,&png_width,&png_height,&depth,&color,NULL,NULL,NULL );
png_set_bgr( png );
#if 0
switch( info->color_type )
{
case PNG_COLOR_TYPE_GRAY_ALPHA: printf( "[png] used GrayA -> stripping alpha channel\n" ); break;
case PNG_COLOR_TYPE_GRAY: printf( "[png] used Gray -> rgb\n" ); break;
case PNG_COLOR_TYPE_PALETTE: printf( "[png] used palette -> rgb\n" ); break;
case PNG_COLOR_TYPE_RGB_ALPHA: printf( "[png] used RGBA -> stripping alpha channel\n" ); break;
case PNG_COLOR_TYPE_RGB: printf( "[png] read rgb datas.\n" ); break;
}
#endif
if ( info->color_type == PNG_COLOR_TYPE_RGB ) data=decoded;
else data=(png_bytep)malloc( png_get_rowbytes( png,info ) * height );
row_p=(png_bytep*)malloc( sizeof( png_bytep ) * png_height );
for ( i=0; i < png_height; i++ ) row_p[i]=&data[png_get_rowbytes( png,info ) * i];
png_read_image( png,row_p );
free( row_p );
switch( info->color_type )
{
case PNG_COLOR_TYPE_GRAY_ALPHA:
mp_msg( MSGT_DECVIDEO,MSGL_INFO,"Sorry gray scaled png with alpha channel not supported at moment.\n" );
free( data );
break;
case PNG_COLOR_TYPE_GRAY:
/* constant 256 colors */
palette=malloc( 1024 );
for ( i=0;i < 256;i++ ) palette[(i*4)]=palette[(i*4)+1]=palette[(i*4)+2]=(char)i;
if (bytes_per_pixel == 4)
palette8torgb32( data,decoded,png_width * png_height,palette );
else
palette8torgb24( data,decoded,png_width * png_height,palette );
free( data );
break;
case PNG_COLOR_TYPE_PALETTE:
{
int cols;
unsigned char * pal;
png_get_PLTE( png,info,(png_colorp*)&pal,&cols );
palette=calloc( 1,cols*4 );
mp_dbg(MSGT_DECVIDEO, MSGL_DBG2, "[mPNG] palette. used colors: %d\n", cols);
for ( i=0;i < cols;i++ )
{
palette[(i*4) ]=pal[(i*3)+2];
palette[(i*4)+1]=pal[(i*3)+1];
palette[(i*4)+2]=pal[(i*3) ];
}
}
if (bytes_per_pixel == 4)
palette8torgb32( data,decoded,png_width * png_height,palette );
else
palette8torgb24( data,decoded,png_width * png_height,palette );
free( data );
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
if (bytes_per_pixel == 4)
memcpy(decoded, data, png_width * png_height * 4);
else
rgb32to24( data,decoded,png_width * png_height * 4 );
free( data );
break;
}
if ( palette ) free( palette );
png_read_end( png,endinfo );
png_destroy_read_struct( &png,&info,&endinfo );
}
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