diff options
Diffstat (limited to 'pngtest.c')
| -rw-r--r-- | pngtest.c | 124 |
1 files changed, 123 insertions, 1 deletions
@@ -550,6 +550,77 @@ png_debug_free(png_structp png_ptr, png_voidp ptr) #endif /* PNG_USER_MEM_SUPPORTED && PNG_DEBUG */ /* END of code to test memory allocation/deallocation */ + + + +/* Demonstration of user chunk support of the sTER and vpAg chunks */ +#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + +/* (sTER is a public chunk not yet understood by libpng. vpAg is a private +chunk used in ImageMagick to store "virtual page" size). */ + +static png_uint_32 user_chunk_data[4]; + + /* 0: stereo mode + 1 + * 1: vpag width + * 2: vpag height + * 3: vpag units + */ + +static int read_user_chunk_callback(png_struct *png_ptr, + png_unknown_chunkp chunk) +{ + png_uint_32 + *user_chunk_data; + + /* Return one of the following: */ + /* return (-n); chunk had an error */ + /* return (0); did not recognize */ + /* return (n); success */ + + /* The unknown chunk structure contains the chunk data: + * png_byte name[5]; + * png_byte *data; + * png_size_t size; + * + * Note that libpng has already taken care of the CRC handling. + */ + + if (chunk->name[0] == 115 && chunk->name[1] == 84 && /* s T */ + chunk->name[2] == 69 && chunk-> name[3] == 82) /* E R */ + { + /* Found sTER chunk */ + if (chunk->size != 1) + return (-1); /* Error return */ + if (chunk->data[0] != 0 && chunk->data[0] != 1) + return (-1); /* Invalid mode */ + user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr); + user_chunk_data[0]=chunk->data[0]+1; + return (1); + } + if (chunk->name[0] != 118 || chunk->name[1] != 112 || /* v p */ + chunk->name[2] != 65 || chunk->name[3] != 103) /* A g */ + return (0); /* Did not recognize */ + + /* Found ImageMagick vpAg chunk */ + + if (chunk->size != 9) + return (-1); /* Error return */ + + user_chunk_data=(png_uint_32 *) png_get_user_chunk_ptr(png_ptr); + + user_chunk_data[1]=(unsigned long) ((chunk->data[0] << 24) | + (chunk->data[1] << 16) | (chunk->data[2] << 8) | chunk->data[3]); + user_chunk_data[2]=(unsigned long) ((chunk->data[4] << 24) | + (chunk->data[5] << 16) | (chunk->data[6] << 8) | chunk->data[7]); + user_chunk_data[3]=(unsigned long) chunk->data[8]; + + return (1); + +} +#endif +/* END of code to demonstrate user chunk support */ + /* Test one file */ int test_one_file(PNG_CONST char *inname, PNG_CONST char *outname) @@ -608,6 +679,16 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname) png_set_error_fn(read_ptr, (png_voidp)inname, pngtest_error, pngtest_warning); #endif + +#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + user_chunk_data[0]=0; + user_chunk_data[1]=0; + user_chunk_data[2]=0; + user_chunk_data[3]=0; + png_set_read_user_chunk_fn(read_ptr, user_chunk_data, + read_user_chunk_callback); +#endif + #ifdef PNG_WRITE_SUPPORTED #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG write_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, png_voidp_NULL, @@ -976,6 +1057,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname) } } #endif + #if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED) { png_unknown_chunkp unknowns; @@ -1003,6 +1085,46 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname) png_write_info_before_PLTE(write_ptr, write_info_ptr); */ png_write_info(write_ptr, write_info_ptr); + +#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) + if (user_chunk_data[0] != 0) + { + png_byte png_sTER[5] = {115, 84, 69, 82, '\0'}; + + unsigned char + ster_chunk_data[1]; + + if(verbose) + fprintf(STDERR, "stereo mode = %lu\n", + (unsigned long)(user_chunk_data[0]-1)); + ster_chunk_data[0]=(unsigned char)(user_chunk_data[0]-1); + png_write_chunk(write_ptr,png_sTER,ster_chunk_data,1); + } + if (user_chunk_data[1] != 0 || user_chunk_data[2] != 0) + { + png_byte png_vpAg[5] = {118, 112, 65, 103, '\0'}; + + unsigned char + vpag_chunk_data[9]; + + if(verbose) + fprintf(STDERR, "vpAg = %lu x %lu, units=%lu\n", + (unsigned long)user_chunk_data[1], + (unsigned long)user_chunk_data[2], + (unsigned long)user_chunk_data[3]); + vpag_chunk_data[0]=(user_chunk_data[1]>>24) & 0xff; + vpag_chunk_data[1]=(user_chunk_data[1]>>16) & 0xff; + vpag_chunk_data[2]=(user_chunk_data[1]>>8 ) & 0xff; + vpag_chunk_data[3]=(user_chunk_data[1] ) & 0xff; + vpag_chunk_data[4]=(user_chunk_data[2]>>24) & 0xff; + vpag_chunk_data[5]=(user_chunk_data[2]>>16) & 0xff; + vpag_chunk_data[6]=(user_chunk_data[2]>>8 ) & 0xff; + vpag_chunk_data[7]=(user_chunk_data[2] ) & 0xff; + vpag_chunk_data[8]=(user_chunk_data[3] ) & 0xff; + png_write_chunk(write_ptr, png_vpAg,vpag_chunk_data,9); + } + +#endif #endif #ifdef SINGLE_ROWBUF_ALLOC @@ -1489,4 +1611,4 @@ main(int argc, char *argv[]) } /* Generate a compiler error if there is an old png.h in the search path. */ -typedef version_1_4_0beta7 your_png_h_is_not_version_1_4_0beta7; +typedef version_1_4_0beta8 your_png_h_is_not_version_1_4_0beta8; |