diff --git a/pngpread.c b/pngpread.c index 7b1149bab..13d48311f 100644 --- a/pngpread.c +++ b/pngpread.c @@ -1026,7 +1026,7 @@ png_push_process_row(png_structp png_ptr) png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); - if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) + if (png_ptr->transformations) png_do_read_transformations(png_ptr); #ifdef PNG_READ_INTERLACING_SUPPORTED diff --git a/pngpriv.h b/pngpriv.h index 7faa8b35d..b6f382e54 100644 --- a/pngpriv.h +++ b/pngpriv.h @@ -340,8 +340,8 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp; #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L #define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L -#define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */ -#define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */ + /* 0x200000L unused */ + /* 0x400000L unused */ #define PNG_FLAG_BENIGN_ERRORS_WARN 0x800000L /* Added to libpng-1.4.0 */ /* 0x1000000L unused */ /* 0x2000000L unused */ @@ -772,8 +772,8 @@ PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info, #if defined(PNG_WRITE_FILLER_SUPPORTED) || \ defined(PNG_READ_STRIP_ALPHA_SUPPORTED) -PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info, - png_bytep row, png_uint_32 flags)); +PNG_EXTERN void png_do_strip_channel PNGARG((png_row_infop row_info, + png_bytep row, int at_start)); #endif #ifdef PNG_16BIT_SUPPORTED diff --git a/pngread.c b/pngread.c index 2e365cd8d..d8741cd12 100644 --- a/pngread.c +++ b/pngread.c @@ -702,7 +702,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) #endif - if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) + if (png_ptr->transformations) png_do_read_transformations(png_ptr); #ifdef PNG_READ_INTERLACING_SUPPORTED diff --git a/pngrtran.c b/pngrtran.c index e6e0c46b4..0ab3d8fd5 100644 --- a/pngrtran.c +++ b/pngrtran.c @@ -149,7 +149,7 @@ png_set_strip_alpha(png_structp png_ptr) if (png_ptr == NULL) return; - png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; + png_ptr->transformations |= PNG_STRIP_ALPHA; } #endif @@ -1073,7 +1073,7 @@ png_init_read_transformations(png_structp png_ptr) */ png_ptr->transformations &= ~PNG_BACKGROUND; png_ptr->transformations &= ~PNG_GAMMA; - png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; + png_ptr->transformations |= PNG_STRIP_ALPHA; } /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ @@ -1207,7 +1207,7 @@ png_init_read_transformations(png_structp png_ptr) /* Handled alpha, still need to strip the channel. */ png_ptr->transformations &= ~PNG_BACKGROUND; - png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; + png_ptr->transformations |= PNG_STRIP_ALPHA; } #endif /* PNG_READ_BACKGROUND_SUPPORTED */ @@ -1353,7 +1353,7 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) info_ptr->channels = 1; #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) + if (png_ptr->transformations & PNG_STRIP_ALPHA) info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; #endif @@ -1454,9 +1454,11 @@ png_do_read_transformations(png_structp png_ptr) #endif #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED - if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) - png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, - PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)); + if ((png_ptr->transformations & PNG_STRIP_ALPHA) && + (png_ptr->row_info.color_type == PNG_COLOR_TYPE_RGB_ALPHA || + png_ptr->row_info.color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1, + 0/*!at_start, because SWAP_ALPHA happens later*/); #endif #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED diff --git a/pngtrans.c b/pngtrans.c index 89661adb4..de18478ef 100644 --- a/pngtrans.c +++ b/pngtrans.c @@ -424,170 +424,115 @@ png_do_packswap(png_row_infop row_info, png_bytep row) #if defined(PNG_WRITE_FILLER_SUPPORTED) || \ defined(PNG_READ_STRIP_ALPHA_SUPPORTED) -/* Remove filler or alpha byte(s) */ +/* Remove a channel - this used to be 'png_do_strip_filler' but it used a + * somewhat weird combination of flags to determine what to do. All the calls + * to png_do_strip_filler are changed in 1.5.2 to call this instead with the + * correct arguments. + * + * The routine isn't general - the channel must be the channel at the start or + * end (not in the middle) of each pixel. + */ void /* PRIVATE */ -png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags) +png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start) { - png_debug(1, "in png_do_strip_filler"); + png_bytep sp = row; /* source pointer */ + png_bytep dp = row; /* destination pointer */ + png_bytep ep = row + row_info->rowbytes; /* One beyond end of row */ + /* At the start sp will point to the first byte to copy and dp to where + * it is copied to. ep always points just beyond the end of the row, so + * the loop simply copies (channels-1) channels until sp reaches ep. + */ + /* GA, GX, XG cases */ + if (row_info->channels == 2) { - png_bytep sp = row; - png_bytep dp = row; - png_uint_32 row_width = row_info->width; - png_uint_32 i; - - if ((row_info->color_type == PNG_COLOR_TYPE_RGB || - (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && - (flags & PNG_FLAG_STRIP_ALPHA))) && - row_info->channels == 4) + if (row_info->bit_depth == 8) { - if (row_info->bit_depth == 8) - { - /* This converts from RGBX or RGBA to RGB */ - if (flags & PNG_FLAG_FILLER_AFTER) - { - dp += 3; sp += 4; - for (i = 1; i < row_width; i++) - { - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - sp++; - } - } + if (at_start) /* Skip initial filler */ + ++sp; + else /* Skip initial channels and, for sp, the filler */ + sp += 2, ++dp; - /* This converts from XRGB or ARGB to RGB */ - else - { - for (i = 0; i < row_width; i++) - { - sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - } - } - row_info->pixel_depth = 24; - row_info->rowbytes = row_width * 3; - } + /* For a 1 pixel wide image there is nothing to do */ + while (sp < ep) + *dp++ = *sp, sp += 2; - else /* if (row_info->bit_depth == 16) */ - { - if (flags & PNG_FLAG_FILLER_AFTER) - { - /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ - sp += 8; dp += 6; - for (i = 1; i < row_width; i++) - { - /* This could be (although png_memcpy is probably slower): - png_memcpy(dp, sp, 6); - sp += 8; - dp += 6; - */ - - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - sp += 2; - } - } - - else - { - /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ - for (i = 0; i < row_width; i++) - { - /* This could be (although png_memcpy is probably slower): - png_memcpy(dp, sp, 6); - sp += 8; - dp += 6; - */ - - sp += 2; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - *dp++ = *sp++; - } - } - - row_info->pixel_depth = 48; - row_info->rowbytes = row_width * 6; - } - row_info->channels = 3; + row_info->pixel_depth = 8; } - else if ((row_info->color_type == PNG_COLOR_TYPE_GRAY || - (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA && - (flags & PNG_FLAG_STRIP_ALPHA))) && - row_info->channels == 2) + else if (row_info->bit_depth == 16) { - if (row_info->bit_depth == 8) - { - if (flags & PNG_FLAG_FILLER_AFTER) - { - /* This converts from GX or GA to G */ - for (i = 0; i < row_width; i++) - { - *dp++ = *sp++; - sp++; - } - } + if (at_start) + sp += 2; + else + sp += 4, dp += 2; - else - { - /* This converts from XG or AG to G */ - for (i = 0; i < row_width; i++) - { - sp++; - *dp++ = *sp++; - } - } + while (sp < ep) + *dp++ = *sp++, *dp++ = *sp, sp += 3; - row_info->pixel_depth = 8; - row_info->rowbytes = row_width; - } - - else /* if (row_info->bit_depth == 16) */ - { - if (flags & PNG_FLAG_FILLER_AFTER) - { - /* This converts from GGXX or GGAA to GG */ - sp += 4; dp += 2; - for (i = 1; i < row_width; i++) - { - *dp++ = *sp++; - *dp++ = *sp++; - sp += 2; - } - } - - else - { - /* This converts from XXGG or AAGG to GG */ - for (i = 0; i < row_width; i++) - { - sp += 2; - *dp++ = *sp++; - *dp++ = *sp++; - } - } - - row_info->pixel_depth = 16; - row_info->rowbytes = row_width * 2; - } - row_info->channels = 1; + row_info->pixel_depth = 16; } - if (flags & PNG_FLAG_STRIP_ALPHA) - row_info->color_type = (png_byte)(row_info->color_type & - ~PNG_COLOR_MASK_ALPHA); + else + return; /* bad bit depth */ + + row_info->channels = 1; + + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_GRAY; } + + /* RGBA, RGBX, XRGB cases */ + else if (row_info->channels == 4) + { + if (row_info->bit_depth == 8) + { + if (at_start) /* Skip initial filler */ + ++sp; + else /* Skip initial channels and, for sp, the filler */ + sp += 4, dp += 3; + + /* Note that the loop adds 3 to dp and 4 to sp each time. */ + while (sp < ep) + *dp++ = *sp++, *dp++ = *sp++, *dp++ = *sp, sp += 2; + + row_info->pixel_depth = 24; + } + + else if (row_info->bit_depth == 16) + { + if (at_start) + sp += 2; + else + sp += 8, dp += 6; + + while (sp < ep) + { + /* Copy 6 bytes, skip 2 */ + *dp++ = *sp++, *dp++ = *sp++; + *dp++ = *sp++, *dp++ = *sp++; + *dp++ = *sp++, *dp++ = *sp, sp += 3; + } + + row_info->pixel_depth = 48; + } + + else + return; /* bad bit depth */ + + row_info->channels = 3; + + /* Finally fix the color type if it records an alpha channel */ + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + row_info->color_type = PNG_COLOR_TYPE_RGB; + } + + else + return; /* The filler channel has gone already */ + + /* Fix the rowbytes value. */ + row_info->rowbytes = dp-row; } #endif diff --git a/pngwtran.c b/pngwtran.c index 115ca3721..ce4c549e3 100644 --- a/pngwtran.c +++ b/pngwtran.c @@ -44,8 +44,8 @@ png_do_write_transformations(png_structp png_ptr) #ifdef PNG_WRITE_FILLER_SUPPORTED if (png_ptr->transformations & PNG_FILLER) - png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, - png_ptr->flags); + png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1, + !(png_ptr->flags & PNG_FILLER_AFTER)); #endif #ifdef PNG_WRITE_PACKSWAP_SUPPORTED