// Get the chunk information of the PNG file. IDAT is marked as existing, only after decoding or reading the header.
// Bits (if set indicates existence of the chunk):
// 0 - gAMA
// 1 - sBIT
// 2 - cHRM
// 3 - PLTE
// 4 - tRNS
// 5 - bKGD
// 6 - hIST
// 7 - pHYs
// 8 - oFFs
// 9 - tIME
// 10 - pCAL
// 11 - sRGB
// 12 - iCCP
// 13 - sPLT
// 14 - sCAL
// 15 - IDAT
// 16:30 - reserved
be_t<u32> pngDecGetChunkInformation(PStream stream, bool IDAT = false)
{
// The end result of the chunk information (bigger-endian)
be_t<u32> chunk_information = 0;
// Needed pointers for getting the chunk information
f64 gamma;
f64 red_x;
f64 red_y;
f64 green_x;
f64 green_y;
f64 blue_x;
f64 blue_y;
f64 white_x;
f64 white_y;
f64 width;
f64 height;
s32 intent;
s32 num_trans;
s32 num_palette;
s32 unit_type;
s32 type;
s32 nparams;
s32 compression_type;
s32 unit;
u16* hist;
u32 proflen;
png_bytep profile;
png_bytep trans_alpha;
png_charp units;
png_charp name;
png_charp purpose;
png_charpp params;
png_int_32 X0;
png_int_32 X1;
png_int_32 offset_x;
png_int_32 offset_y;
png_uint_32 res_x;
png_uint_32 res_y;
png_colorp palette;
png_color_8p sig_bit;
png_color_16p background;
png_color_16p trans_color;
png_sPLT_tp entries;
png_timep mod_time;
// Get chunk information and set the appropriate bits
if (png_get_gAMA(stream->png_ptr, stream->info_ptr, &gamma))
{
chunk_information |= 1 << 0; // gAMA
}
if (png_get_sBIT(stream->png_ptr, stream->info_ptr, &sig_bit))
{
chunk_information |= 1 << 1; // sBIT
}
if (png_get_cHRM(stream->png_ptr, stream->info_ptr, &white_x, &white_y, &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y))
{
chunk_information |= 1 << 2; // cHRM
}
if (png_get_PLTE(stream->png_ptr, stream->info_ptr, &palette, &num_palette))
{
chunk_information |= 1 << 3; // PLTE
}
if (png_get_tRNS(stream->png_ptr, stream->info_ptr, &trans_alpha, &num_trans, &trans_color))
{
chunk_information |= 1 << 4; // tRNS
}
if (png_get_bKGD(stream->png_ptr, stream->info_ptr, &background))
{
chunk_information |= 1 << 5; // bKGD
}
if (png_get_hIST(stream->png_ptr, stream->info_ptr, &hist))
{
chunk_information |= 1 << 6; // hIST
}
if (png_get_pHYs(stream->png_ptr, stream->info_ptr, &res_x, &res_y, &unit_type))
{
chunk_information |= 1 << 7; // pHYs
}
if (png_get_oFFs(stream->png_ptr, stream->info_ptr, &offset_x, &offset_y, &unit_type))
{
chunk_information |= 1 << 8; // oFFs
}
if (png_get_tIME(stream->png_ptr, stream->info_ptr, &mod_time))
{
chunk_information |= 1 << 9; // tIME
}
if (png_get_pCAL(stream->png_ptr, stream->info_ptr, &purpose, &X0, &X1, &type, &nparams, &units, ¶ms))
{
chunk_information |= 1 << 10; // pCAL
}
if (png_get_sRGB(stream->png_ptr, stream->info_ptr, &intent))
{
chunk_information |= 1 << 11; // sRGB
}
if (png_get_iCCP(stream->png_ptr, stream->info_ptr, &name, &compression_type, &profile, &proflen))
{
chunk_information |= 1 << 12; // iCCP
}
if (png_get_sPLT(stream->png_ptr, stream->info_ptr, &entries))
{
chunk_information |= 1 << 13; // sPLT
}
if (png_get_sCAL(stream->png_ptr, stream->info_ptr, &unit, &width, &height))
{
chunk_information |= 1 << 14; // sCAL
}
if (IDAT)
{
chunk_information |= 1 << 15; // IDAT
}
return chunk_information;
}
int main( int argc, char *argv[] ) {
int f, rowbytes;
char buf[256];
static FILE *fpout; /* "static" prevents setjmp corruption */
png_structp write_ptr;
png_infop write_info_ptr, end_info_ptr;
png_bytep row_buf, here;
png_uint_32 y;
png_textp text_ptr, new_text_ptr;
int num_text;
int interlace_type, compression_type, filter_type, bit_depth, color_type;
int it, ct, ft, bd, clrt;
png_uint_32 width, height, w, h;
int duration;
if( argc < 4 ) {
printf( "makeanim v0.2\nusage: makeanim <duration in milliseconds> <input files ...> <output file>\n" );
printf( "example: makeanim 1500 a00.png a01.png a02.png a03.png a04.png a.anim\n" );
return 1;
}
duration = atoi( argv[1] );
if( duration < 1 ) {
printf( "duration is incorrect\n" );
return 1;
}
numfiles = argc - 3;
input = (struct inputstruct *)malloc( sizeof( struct inputstruct ) * numfiles );
if( !input ) return 1;
for( f = 0; f < numfiles; f++ ) {
input[f].name = argv[f + 2];
printf( "opening file %d, \"%s\"\n", f, input[f].name );
/* open the file handle */
input[f].file = fopen( input[f].name, "rb" );
if( input[f].file == NULL ) {
printf( "fopen() failed\n" );
return 1;
}
/* check if it's PNG */
if( fread( buf, 1, 8, input[f].file ) != 8 ) {
printf( "fread() failed for file \"%s\"\n", input[f].name );
return 1;
}
if( png_sig_cmp( buf, (png_size_t)0, 8 ) ) {
printf( "not a PNG file\n" );
return 1;
}
fseek( input[f].file, 0, SEEK_SET );
/* allocate read structure */
input[f].read_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING, (png_voidp)NULL, (png_error_ptr)NULL, (png_error_ptr)NULL );
if( input[f].read_ptr == NULL ) {
printf( "png_create_read_struct() failed\n" );
return 1;
}
/* allocate read info structure */
input[f].read_info_ptr = png_create_info_struct( input[f].read_ptr );
if( input[f].read_info_ptr == NULL ) {
printf( "png_create_info_struct() failed\n" );
return 1;
}
/* set error handler code */
if( setjmp( input[f].read_ptr->jmpbuf ) ) {
printf( "libpng read error\n" );
return 1;
}
/* initialize stream */
png_init_io( input[f].read_ptr, input[f].file );
png_set_read_status_fn( input[f].read_ptr, NULL );
/* read png info struct */
png_read_info( input[f].read_ptr, input[f].read_info_ptr );
/* get the info */
if( !png_get_IHDR( input[f].read_ptr, input[f].read_info_ptr, &w, &h, &bd, &clrt, &it, &ct, &ft ) ) {
printf( "png_get_IHDR() failed\n" );
return 1;
}
/* save the info of the first frame */
if( f == 0 ) {
width = w;
height = h;
bit_depth = bd;
color_type = clrt;
interlace_type = it;
compression_type = ct;
filter_type = ft;
}
/* compare all other frames to first frame */
else if( (w != width) ||
(h != height) ||
(bd != bit_depth) ||
(clrt != color_type) ||
(it != interlace_type) ||
(ct != compression_type) ||
(ft != filter_type) ) {
if( w != width ) printf( "width is different\n" );
if( h != height ) printf( "height is different\n" );
if( bd != bit_depth ) printf( "bit depth is different\n" );
if( clrt != color_type ) printf( "color type is different\n" );
if( it != interlace_type ) printf( "interlace type is different\n" );
if( ct != compression_type ) printf( "compression type is different\n" );
if( ft != filter_type ) printf( "filter type is different\n" );
return 1;
}
}
row_buf = (png_bytep)NULL;
/* open output file */
printf( "opening file \"%s\"\n", argv[numfiles + 2] );
fpout = fopen( argv[numfiles + 2], "wb" );
if( fpout == NULL ) {
printf( "fopen() failed\n" );
return 1;
}
/* allocate write structure */
write_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, (png_voidp)NULL, (png_error_ptr)NULL, (png_error_ptr)NULL );
/* allocate info structures */
write_info_ptr = png_create_info_struct( write_ptr );
end_info_ptr = png_create_info_struct( write_ptr );
/* error handling */
if( setjmp( write_ptr->jmpbuf ) ) {
printf( "libpng write error\n" );
return 1;
}
/* initialize output stream */
png_init_io( write_ptr, fpout );
png_set_write_status_fn( write_ptr, NULL );
/* set info */
png_set_IHDR( write_ptr, write_info_ptr, width * numfiles, height, bit_depth, color_type, PNG_INTERLACE_NONE, compression_type, filter_type);
/* image characteristics */
{
png_color_16p background;
double white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
double gamma;
int intent;
png_uint_16p hist;
png_uint_32 offset_x, offset_y;
int unit_type;
png_charp purpose, units;
png_charpp params;
png_int_32 X0, X1;
int type, nparams;
png_uint_32 res_x, res_y;
png_colorp palette;
int num_palette;
png_color_8p sig_bit;
png_bytep trans;
int num_trans;
png_color_16p trans_values;
/* background color */
if( png_get_bKGD( input[0].read_ptr, input[0].read_info_ptr, &background ) ) {
png_set_bKGD( write_ptr, write_info_ptr, background );
}
if( png_get_cHRM( input[0].read_ptr, input[0].read_info_ptr, &white_x, &white_y, &red_x, &red_y, &green_x, &green_y, &blue_x, &blue_y ) ) {
png_set_cHRM( write_ptr, write_info_ptr, white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y );
}
/* gamma */
if( png_get_gAMA( input[0].read_ptr, input[0].read_info_ptr, &gamma ) ) {
png_set_gAMA( write_ptr, write_info_ptr, gamma );
}
/* rendering intent */
if( png_get_sRGB( input[0].read_ptr, input[0].read_info_ptr, &intent ) ) {
png_set_sRGB( write_ptr, write_info_ptr, intent );
}
/* Histogram */
if( png_get_hIST( input[0].read_ptr, input[0].read_info_ptr, &hist ) ) {
png_set_hIST( write_ptr, write_info_ptr, hist );
}
/* offsets */
if( png_get_oFFs( input[0].read_ptr, input[0].read_info_ptr, &offset_x, &offset_y, &unit_type ) ) {
png_set_oFFs( write_ptr, write_info_ptr, offset_x, offset_y, unit_type );
}
if( png_get_pCAL( input[0].read_ptr, input[0].read_info_ptr, &purpose, &X0, &X1, &type, &nparams, &units, ¶ms ) ) {
png_set_pCAL( write_ptr, write_info_ptr, purpose, X0, X1, type, nparams, units, params );
}
/* pixel density */
if( png_get_pHYs( input[0].read_ptr, input[0].read_info_ptr, &res_x, &res_y, &unit_type ) ) {
png_set_pHYs( write_ptr, write_info_ptr, res_x, res_y, unit_type );
}
/* text chunks */
/* if( png_get_text( input[0].read_ptr, input[0].read_info_ptr, &text_ptr, &num_text ) > 0 ) {
printf( "Handling %d tEXt/zTXt chunks\n", num_text );
png_set_text( write_ptr, write_info_ptr, text_ptr, num_text );
}
*/
/* palette */
if( png_get_PLTE( input[0].read_ptr, input[0].read_info_ptr, &palette, &num_palette ) ) {
png_set_PLTE( write_ptr, write_info_ptr, palette, num_palette );
}
/* significant bits */
if( png_get_sBIT( input[0].read_ptr, input[0].read_info_ptr, &sig_bit ) ) {
png_set_sBIT( write_ptr, write_info_ptr, sig_bit );
}
/* transparency */
if( png_get_tRNS( input[0].read_ptr, input[0].read_info_ptr, &trans, &num_trans, &trans_values ) ) {
png_set_tRNS( write_ptr, write_info_ptr, trans, num_trans, trans_values );
}
}
/* text chunks */
num_text = 0;
if( !png_get_text( input[0].read_ptr, input[0].read_info_ptr, &text_ptr, &num_text ) ) num_text = 0;
new_text_ptr = (struct png_text_struct *)malloc( sizeof( struct png_text_struct ) * num_text + 1 );
if( !new_text_ptr ) {
printf( "malloc() failed\n" );
return 1;
}
memcpy( new_text_ptr, text_ptr, sizeof( struct png_text_struct ) * num_text );
snprintf( buf, 255, "SDL_anim %d %d %d", duration, width, numfiles );
buf[255] = 0;
new_text_ptr[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
new_text_ptr[num_text].key = "format";
new_text_ptr[num_text].text = buf;
new_text_ptr[num_text].text_length = strlen( buf );
num_text++;
png_set_text( write_ptr, write_info_ptr, new_text_ptr, num_text );
/* write info */
png_write_info( write_ptr, write_info_ptr );
/* allocate buffer */
rowbytes = png_get_rowbytes( input[0].read_ptr, input[0].read_info_ptr );
row_buf = (png_bytep)png_malloc( write_ptr, rowbytes * numfiles );
if( row_buf == NULL ) {
printf( "png_malloc() failed\n" );
return 1;
}
/* copy raw data */
for( y = 0; y < height; y++ ) {
/* grab a scanline from each file */
here = row_buf;
for( f = 0; f < numfiles; f++ ) {
png_read_rows( input[f].read_ptr, (png_bytepp)&here, (png_bytepp)NULL, 1 );
here += rowbytes;
}
/* write the long scanline */
png_write_rows( write_ptr, (png_bytepp)&row_buf, 1 );
}
/* end io */
for( f = 0; f < numfiles; f++ ) png_read_end( input[f].read_ptr, end_info_ptr );
png_write_end( write_ptr, end_info_ptr );
/* cleanup */
png_free( write_ptr, row_buf );
for( f = 0; f < numfiles; f++ ) {
png_destroy_read_struct( &input[f].read_ptr, &input[f].read_info_ptr, &end_info_ptr);
fclose( input[f].file );
}
png_destroy_write_struct( &write_ptr, &write_info_ptr );
fclose( fpout );
return 0;
}
