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author | Tor Andersson <tor.andersson@artifex.com> | 2013-06-19 15:29:44 +0200 |
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committer | Tor Andersson <tor.andersson@artifex.com> | 2013-06-20 16:45:35 +0200 |
commit | 0a927854a10e1e6b9770a81e2e1d9f3093631757 (patch) | |
tree | 3d65d820d9fdba2d0d394d99c36290c851b78ca0 /source/fitz/load-png.c | |
parent | 1ae8f19179c5f0f8c6352b3c7855465325d5449a (diff) | |
download | mupdf-0a927854a10e1e6b9770a81e2e1d9f3093631757.tar.xz |
Rearrange source files.
Diffstat (limited to 'source/fitz/load-png.c')
-rw-r--r-- | source/fitz/load-png.c | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/source/fitz/load-png.c b/source/fitz/load-png.c new file mode 100644 index 00000000..ad22e128 --- /dev/null +++ b/source/fitz/load-png.c @@ -0,0 +1,599 @@ +#include "mupdf/fitz.h" + +#include <zlib.h> + +struct info +{ + fz_context *ctx; + unsigned int width, height, depth, n; + int interlace, indexed; + unsigned int size; + unsigned char *samples; + unsigned char palette[256*4]; + int transparency; + int trns[3]; + int xres, yres; +}; + +static inline unsigned int getuint(unsigned char *p) +{ + return p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3]; +} + +static inline int getcomp(unsigned char *line, int x, int bpc) +{ + switch (bpc) + { + case 1: return (line[x >> 3] >> ( 7 - (x & 7) ) ) & 1; + case 2: return (line[x >> 2] >> ( ( 3 - (x & 3) ) << 1 ) ) & 3; + case 4: return (line[x >> 1] >> ( ( 1 - (x & 1) ) << 2 ) ) & 15; + case 8: return line[x]; + case 16: return line[x << 1] << 8 | line[(x << 1) + 1]; + } + return 0; +} + +static inline void putcomp(unsigned char *line, int x, int bpc, int value) +{ + int maxval = (1 << bpc) - 1; + + switch (bpc) + { + case 1: line[x >> 3] &= ~(maxval << (7 - (x & 7))); break; + case 2: line[x >> 2] &= ~(maxval << ((3 - (x & 3)) << 1)); break; + case 4: line[x >> 1] &= ~(maxval << ((1 - (x & 1)) << 2)); break; + } + + switch (bpc) + { + case 1: line[x >> 3] |= value << (7 - (x & 7)); break; + case 2: line[x >> 2] |= value << ((3 - (x & 3)) << 1); break; + case 4: line[x >> 1] |= value << ((1 - (x & 1)) << 2); break; + case 8: line[x] = value; break; + case 16: line[x << 1] = value >> 8; line[(x << 1) + 1] = value & 0xFF; break; + } +} + +static const unsigned char png_signature[8] = +{ + 137, 80, 78, 71, 13, 10, 26, 10 +}; + +static void *zalloc(void *opaque, unsigned int items, unsigned int size) +{ + return fz_malloc_array(opaque, items, size); +} + +static void zfree(void *opaque, void *address) +{ + fz_free(opaque, address); +} + +static inline int paeth(int a, int b, int c) +{ + /* The definitions of ac and bc are correct, not a typo. */ + int ac = b - c, bc = a - c, abcc = ac + bc; + int pa = (ac < 0 ? -ac : ac); + int pb = (bc < 0 ? -bc : bc); + int pc = (abcc < 0 ? -abcc : abcc); + return pa <= pb && pa <= pc ? a : pb <= pc ? b : c; +} + +static void +png_predict(unsigned char *samples, unsigned int width, unsigned int height, unsigned int n, unsigned int depth) +{ + unsigned int stride = (width * n * depth + 7) / 8; + unsigned int bpp = (n * depth + 7) / 8; + unsigned int i, row; + + for (row = 0; row < height; row ++) + { + unsigned char *src = samples + (unsigned int)((stride + 1) * row); + unsigned char *dst = samples + (unsigned int)(stride * row); + + unsigned char *a = dst; + unsigned char *b = dst - stride; + unsigned char *c = dst - stride; + + switch (*src++) + { + default: + case 0: /* None */ + for (i = 0; i < stride; i++) + *dst++ = *src++; + break; + + case 1: /* Sub */ + for (i = 0; i < bpp; i++) + *dst++ = *src++; + for (i = bpp; i < stride; i++) + *dst++ = *src++ + *a++; + break; + + case 2: /* Up */ + if (row == 0) + for (i = 0; i < stride; i++) + *dst++ = *src++; + else + for (i = 0; i < stride; i++) + *dst++ = *src++ + *b++; + break; + + case 3: /* Average */ + if (row == 0) + { + for (i = 0; i < bpp; i++) + *dst++ = *src++; + for (i = bpp; i < stride; i++) + *dst++ = *src++ + (*a++ >> 1); + } + else + { + for (i = 0; i < bpp; i++) + *dst++ = *src++ + (*b++ >> 1); + for (i = bpp; i < stride; i++) + *dst++ = *src++ + ((*b++ + *a++) >> 1); + } + break; + + case 4: /* Paeth */ + if (row == 0) + { + for (i = 0; i < bpp; i++) + *dst++ = *src++ + paeth(0, 0, 0); + for (i = bpp; i < stride; i++) + *dst++ = *src++ + paeth(*a++, 0, 0); + } + else + { + for (i = 0; i < bpp; i++) + *dst++ = *src++ + paeth(0, *b++, 0); + for (i = bpp; i < stride; i++) + *dst++ = *src++ + paeth(*a++, *b++, *c++); + } + break; + } + } +} + +static const unsigned int adam7_ix[7] = { 0, 4, 0, 2, 0, 1, 0 }; +static const unsigned int adam7_dx[7] = { 8, 8, 4, 4, 2, 2, 1 }; +static const unsigned int adam7_iy[7] = { 0, 0, 4, 0, 2, 0, 1 }; +static const unsigned int adam7_dy[7] = { 8, 8, 8, 4, 4, 2, 2 }; + +static void +png_deinterlace_passes(struct info *info, unsigned int *w, unsigned int *h, unsigned int *ofs) +{ + int p, bpp = info->depth * info->n; + ofs[0] = 0; + for (p = 0; p < 7; p++) + { + w[p] = (info->width + adam7_dx[p] - adam7_ix[p] - 1) / adam7_dx[p]; + h[p] = (info->height + adam7_dy[p] - adam7_iy[p] - 1) / adam7_dy[p]; + if (w[p] == 0) h[p] = 0; + if (h[p] == 0) w[p] = 0; + if (w[p] && h[p]) + ofs[p + 1] = ofs[p] + h[p] * (1 + (w[p] * bpp + 7) / 8); + else + ofs[p + 1] = ofs[p]; + } +} + +static void +png_deinterlace(struct info *info, unsigned int *passw, unsigned int *passh, unsigned int *passofs) +{ + unsigned int n = info->n; + unsigned int depth = info->depth; + unsigned int stride = (info->width * n * depth + 7) / 8; + unsigned char *output; + unsigned int p, x, y, k; + + output = fz_malloc_array(info->ctx, info->height, stride); + + for (p = 0; p < 7; p++) + { + unsigned char *sp = info->samples + (passofs[p]); + unsigned int w = passw[p]; + unsigned int h = passh[p]; + + png_predict(sp, w, h, n, depth); + for (y = 0; y < h; y++) + { + for (x = 0; x < w; x++) + { + int outx = x * adam7_dx[p] + adam7_ix[p]; + int outy = y * adam7_dy[p] + adam7_iy[p]; + unsigned char *dp = output + outy * stride; + for (k = 0; k < n; k++) + { + int v = getcomp(sp, x * n + k, depth); + putcomp(dp, outx * n + k, depth, v); + } + } + sp += (w * depth * n + 7) / 8; + } + } + + fz_free(info->ctx, info->samples); + info->samples = output; +} + +static void +png_read_ihdr(struct info *info, unsigned char *p, unsigned int size) +{ + int color, compression, filter; + + if (size != 13) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "IHDR chunk is the wrong size"); + + info->width = getuint(p + 0); + info->height = getuint(p + 4); + info->depth = p[8]; + + color = p[9]; + compression = p[10]; + filter = p[11]; + info->interlace = p[12]; + + if (info->width <= 0) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "image width must be > 0"); + if (info->height <= 0) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "image height must be > 0"); + + if (info->depth != 1 && info->depth != 2 && info->depth != 4 && + info->depth != 8 && info->depth != 16) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "image bit depth must be one of 1, 2, 4, 8, 16"); + if (color == 2 && info->depth < 8) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "illegal bit depth for truecolor"); + if (color == 3 && info->depth > 8) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "illegal bit depth for indexed"); + if (color == 4 && info->depth < 8) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "illegal bit depth for grayscale with alpha"); + if (color == 6 && info->depth < 8) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "illegal bit depth for truecolor with alpha"); + + info->indexed = 0; + if (color == 0) /* gray */ + info->n = 1; + else if (color == 2) /* rgb */ + info->n = 3; + else if (color == 4) /* gray alpha */ + info->n = 2; + else if (color == 6) /* rgb alpha */ + info->n = 4; + else if (color == 3) /* indexed */ + { + info->indexed = 1; + info->n = 1; + } + else + fz_throw(info->ctx, FZ_ERROR_GENERIC, "unknown color type"); + + if (compression != 0) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "unknown compression method"); + if (filter != 0) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "unknown filter method"); + if (info->interlace != 0 && info->interlace != 1) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "interlace method not supported"); +} + +static void +png_read_plte(struct info *info, unsigned char *p, unsigned int size) +{ + int n = size / 3; + int i; + + if (n > 256) + { + fz_warn(info->ctx, "too many samples in palette"); + n = 256; + } + + for (i = 0; i < n; i++) + { + info->palette[i * 4] = p[i * 3]; + info->palette[i * 4 + 1] = p[i * 3 + 1]; + info->palette[i * 4 + 2] = p[i * 3 + 2]; + } + + /* Fill in any missing palette entries */ + for (; i < 256; i++) + { + info->palette[i * 4] = 0; + info->palette[i * 4 + 1] = 0; + info->palette[i * 4 + 2] = 0; + } +} + +static void +png_read_trns(struct info *info, unsigned char *p, unsigned int size) +{ + unsigned int i; + + info->transparency = 1; + + if (info->indexed) + { + if (size > 256) + { + fz_warn(info->ctx, "too many samples in transparency table"); + size = 256; + } + for (i = 0; i < size; i++) + info->palette[i * 4 + 3] = p[i]; + /* Fill in any missing entries */ + for (; i < 256; i++) + info->palette[i * 4 + 3] = 255; + } + else + { + if (size != info->n * 2) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "tRNS chunk is the wrong size"); + for (i = 0; i < info->n; i++) + info->trns[i] = (p[i * 2] << 8 | p[i * 2 + 1]) & ((1 << info->depth) - 1); + } +} + +static void +png_read_idat(struct info *info, unsigned char *p, unsigned int size, z_stream *stm) +{ + int code; + + stm->next_in = p; + stm->avail_in = size; + + code = inflate(stm, Z_SYNC_FLUSH); + if (code != Z_OK && code != Z_STREAM_END) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "zlib error: %s", stm->msg); + if (stm->avail_in != 0) + { + if (stm->avail_out == 0) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "ran out of output before input"); + fz_throw(info->ctx, FZ_ERROR_GENERIC, "inflate did not consume buffer (%d remaining)", stm->avail_in); + } +} + +static void +png_read_phys(struct info *info, unsigned char *p, unsigned int size) +{ + if (size != 9) + fz_throw(info->ctx, FZ_ERROR_GENERIC, "pHYs chunk is the wrong size"); + if (p[8] == 1) + { + info->xres = getuint(p) * 254 / 10000; + info->yres = getuint(p + 4) * 254 / 10000; + } +} + +static void +png_read_image(fz_context *ctx, struct info *info, unsigned char *p, unsigned int total) +{ + unsigned int passw[7], passh[7], passofs[8]; + unsigned int code, size; + z_stream stm; + + memset(info, 0, sizeof (struct info)); + info->ctx = ctx; + memset(info->palette, 255, sizeof(info->palette)); + info->xres = 96; + info->yres = 96; + + /* Read signature */ + + if (total < 8 + 12 || memcmp(p, png_signature, 8)) + fz_throw(ctx, FZ_ERROR_GENERIC, "not a png image (wrong signature)"); + + p += 8; + total -= 8; + + /* Read IHDR chunk (must come first) */ + + size = getuint(p); + if (total < 12 || size > total - 12) + fz_throw(ctx, FZ_ERROR_GENERIC, "premature end of data in png image"); + + if (!memcmp(p + 4, "IHDR", 4)) + png_read_ihdr(info, p + 8, size); + else + fz_throw(ctx, FZ_ERROR_GENERIC, "png file must start with IHDR chunk"); + + p += size + 12; + total -= size + 12; + + /* Prepare output buffer */ + + if (!info->interlace) + { + info->size = info->height * (1 + (info->width * info->n * info->depth + 7) / 8); + } + else + { + png_deinterlace_passes(info, passw, passh, passofs); + info->size = passofs[7]; + } + + info->samples = fz_malloc(ctx, info->size); + + stm.zalloc = zalloc; + stm.zfree = zfree; + stm.opaque = ctx; + + stm.next_out = info->samples; + stm.avail_out = info->size; + + code = inflateInit(&stm); + if (code != Z_OK) + { + fz_free(ctx, info->samples); + fz_throw(ctx, FZ_ERROR_GENERIC, "zlib error: %s", stm.msg); + } + + fz_try(ctx) + { + /* Read remaining chunks until IEND */ + while (total > 8) + { + size = getuint(p); + + if (total < 12 || size > total - 12) + fz_throw(ctx, FZ_ERROR_GENERIC, "premature end of data in png image"); + + if (!memcmp(p + 4, "PLTE", 4)) + png_read_plte(info, p + 8, size); + if (!memcmp(p + 4, "tRNS", 4)) + png_read_trns(info, p + 8, size); + if (!memcmp(p + 4, "pHYs", 4)) + png_read_phys(info, p + 8, size); + if (!memcmp(p + 4, "IDAT", 4)) + png_read_idat(info, p + 8, size, &stm); + if (!memcmp(p + 4, "IEND", 4)) + break; + + p += size + 12; + total -= size + 12; + } + } + fz_catch(ctx) + { + inflateEnd(&stm); + fz_free(ctx, info->samples); + fz_rethrow(ctx); + } + + code = inflateEnd(&stm); + if (code != Z_OK) + { + fz_free(ctx, info->samples); + fz_throw(ctx, FZ_ERROR_GENERIC, "zlib error: %s", stm.msg); + } + + /* Apply prediction filter and deinterlacing */ + fz_try(ctx) + { + if (!info->interlace) + png_predict(info->samples, info->width, info->height, info->n, info->depth); + else + png_deinterlace(info, passw, passh, passofs); + } + fz_catch(ctx) + { + fz_free(ctx, info->samples); + fz_rethrow(ctx); + } +} + +static fz_pixmap * +png_expand_palette(fz_context *ctx, struct info *info, fz_pixmap *src) +{ + fz_pixmap *dst = fz_new_pixmap(ctx, fz_device_rgb(ctx), src->w, src->h); + unsigned char *sp = src->samples; + unsigned char *dp = dst->samples; + unsigned int x, y; + + dst->xres = src->xres; + dst->yres = src->yres; + + for (y = info->height; y > 0; y--) + { + for (x = info->width; x > 0; x--) + { + int v = *sp << 2; + *dp++ = info->palette[v]; + *dp++ = info->palette[v + 1]; + *dp++ = info->palette[v + 2]; + *dp++ = info->palette[v + 3]; + sp += 2; + } + } + + fz_drop_pixmap(info->ctx, src); + return dst; +} + +static void +png_mask_transparency(struct info *info, fz_pixmap *dst) +{ + unsigned int stride = (info->width * info->n * info->depth + 7) / 8; + unsigned int depth = info->depth; + unsigned int n = info->n; + unsigned int x, y, k, t; + + for (y = 0; y < info->height; y++) + { + unsigned char *sp = info->samples + (unsigned int)(y * stride); + unsigned char *dp = dst->samples + (unsigned int)(y * dst->w * dst->n); + for (x = 0; x < info->width; x++) + { + t = 1; + for (k = 0; k < n; k++) + if (getcomp(sp, x * n + k, depth) != info->trns[k]) + t = 0; + if (t) + dp[x * dst->n + dst->n - 1] = 0; + } + } +} + +fz_pixmap * +fz_load_png(fz_context *ctx, unsigned char *p, int total) +{ + fz_pixmap *image; + fz_colorspace *colorspace; + struct info png; + int stride; + + png_read_image(ctx, &png, p, total); + + if (png.n == 3 || png.n == 4) + colorspace = fz_device_rgb(ctx); + else + colorspace = fz_device_gray(ctx); + + stride = (png.width * png.n * png.depth + 7) / 8; + + fz_try(ctx) + { + image = fz_new_pixmap(ctx, colorspace, png.width, png.height); + } + fz_catch(ctx) + { + fz_free(png.ctx, png.samples); + fz_rethrow_message(ctx, "out of memory loading png"); + } + + image->xres = png.xres; + image->yres = png.yres; + + fz_unpack_tile(image, png.samples, png.n, png.depth, stride, png.indexed); + + if (png.indexed) + image = png_expand_palette(ctx, &png, image); + else if (png.transparency) + png_mask_transparency(&png, image); + + if (png.transparency || png.n == 2 || png.n == 4) + fz_premultiply_pixmap(png.ctx, image); + + fz_free(png.ctx, png.samples); + + return image; +} + +void +fz_load_png_info(fz_context *ctx, unsigned char *p, int total, int *wp, int *hp, int *xresp, int *yresp, fz_colorspace **cspacep) +{ + struct info png; + + png_read_image(ctx, &png, p, total); + + if (png.n == 3 || png.n == 4) + *cspacep = fz_device_rgb(ctx); + else + *cspacep = fz_device_gray(ctx); + + *wp = png.width; + *hp = png.height; + *xresp = png.xres; + *yresp = png.xres; + fz_free(png.ctx, png.samples); +} |