Cleanup and better safety checks, 4

aaaaaa123456789 · Jan 20, 2022 · 2bdb87e · 2bdb87e
1 parent 2c01168
commit 2bdb87e
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Showing 4 changed files with 16 additions and 12 deletions.
diff --git a/src/gifwrite.c b/src/gifwrite.c
@@ -24,7 +24,7 @@ void generate_GIF_data (struct context * context) {
 void generate_GIF_data_with_palette (struct context * context, unsigned char * header) {
   uint_fast16_t colors = context -> source -> max_palette_index + 1;
   uint32_t * palette = ctxcalloc(context, 256 * sizeof *palette);
-  plum_convert_colors(palette, context -> source -> palette, context -> source -> max_palette_index + 1, PLUM_COLOR_32, context -> source -> color_format);
+  plum_convert_colors(palette, context -> source -> palette, colors, PLUM_COLOR_32, context -> source -> color_format);
   int transparent = -1;
   uint8_t * mapping = NULL;
   uint_fast32_t p;

diff --git a/src/jpegcomponents.c b/src/jpegcomponents.c
@@ -151,11 +151,7 @@ void JPEG_transfer_RGB (uint64_t * restrict output, size_t count, unsigned limit
 }
 
 void JPEG_transfer_BGR (uint64_t * restrict output, size_t count, unsigned limit, const double ** input) {
-  double factor = 65535.0 / limit;
-  const double * red = input[2];
-  const double * green = input[1];
-  const double * blue = *input;
-  while (count --) *(output ++) = color_from_floats(*(red ++) * factor, *(green ++) * factor, *(blue ++) * factor, 0);
+  JPEG_transfer_RGB(output, count, limit, (const double * []) {input[2], input[1], *input});
 }
 
 void JPEG_transfer_ABGR (uint64_t * restrict output, size_t count, unsigned limit, const double ** input) {
@@ -262,7 +258,7 @@ void JPEG_transfer_CMYK (uint64_t * restrict output, size_t count, unsigned limi
   const double * yellow = input[2];
   const double * black = input[3];
   while (count --) {
-    double scale = factor * *(black ++);
+    double scale = *(black ++) * factor;
     *(output ++) = color_from_floats(*(cyan ++) * scale, *(magenta ++) * scale, *(yellow ++) * scale, 0);
   }
 }

diff --git a/src/jpegcompress.c b/src/jpegcompress.c
@@ -7,10 +7,14 @@ struct JPEG_encoded_value * generate_JPEG_luminance_data_stream (struct context
   struct JPEG_encoded_value * result = ctxmalloc(context, sizeof *result * allocated);
   double predicted = 0.0;
   for (unit = 0; unit < units; unit ++) {
-    if ((allocated - *count) < 64) result = ctxrealloc(context, result, sizeof *result * (allocated += 3 * (units - unit) + 64));
+    if ((allocated - *count) < 64) {
+      size_t newsize = allocated + 3 * (units - unit) + 64;
+      if (newsize < allocated) throw(context, PLUM_ERR_IMAGE_TOO_LARGE);
+      result = ctxrealloc(context, result, sizeof *result * (allocated = newsize));
+    }
     predicted = generate_JPEG_data_unit(result, count, data[unit], quantization, predicted);
   }
-  return ctxrealloc(context, result, sizeof *result * *count);
+  return ctxrealloc(context, result, *count * sizeof *result);
 }
 
 struct JPEG_encoded_value * generate_JPEG_chrominance_data_stream (struct context * context, double (* restrict blue)[64], double (* restrict red)[64],
@@ -20,11 +24,15 @@ struct JPEG_encoded_value * generate_JPEG_chrominance_data_stream (struct contex
   struct JPEG_encoded_value * result = ctxmalloc(context, sizeof *result * allocated);
   double predicted_blue = 0.0, predicted_red = 0.0;
   for (unit = 0; unit < units; unit ++) {
-    if ((allocated - *count) < 128) result = ctxrealloc(context, result, sizeof *result * (allocated += 6 * (units - unit) + 128));
+    if ((allocated - *count) < 128) {
+      size_t newsize = allocated + 6 * (units - unit) + 128;
+      if (newsize < allocated) throw(context, PLUM_ERR_IMAGE_TOO_LARGE);
+      result = ctxrealloc(context, result, sizeof *result * (allocated = newsize));
+    }
     predicted_blue = generate_JPEG_data_unit(result, count, blue[unit], quantization, predicted_blue);
     predicted_red = generate_JPEG_data_unit(result, count, red[unit], quantization, predicted_red);
   }
-  return ctxrealloc(context, result, sizeof *result * *count);
+  return ctxrealloc(context, result, *count * sizeof *result);
 }
 
 double generate_JPEG_data_unit (struct JPEG_encoded_value * data, size_t * restrict count, const double unit[restrict static 64],

diff --git a/src/jpegdct.c b/src/jpegdct.c
@@ -35,7 +35,7 @@ double apply_JPEG_DCT (int16_t output[restrict static 64], const double input[re
                                        4, 5, 6, 7, 7, 6, 5, 4, 3, 2, 1, 2, 3, 4, 5, 6, 7, 7, 6, 5, 4, 3, 4, 5, 6, 7, 7, 6, 5, 6, 7, 7};
   static const unsigned char cols[] = {0, 1, 0, 0, 1, 2, 3, 2, 1, 0, 0, 1, 2, 3, 4, 5, 4, 3, 2, 1, 0, 0, 1, 2, 3, 4, 5, 6, 7, 6, 5, 4,
                                        3, 2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 7, 6, 5, 4, 3, 2, 3, 4, 5, 6, 7, 7, 6, 5, 4, 5, 6, 7, 7, 6, 7};
-  // zero flushing threshold: for later coefficients, round some values slightly larger than 0.5 to 0 instead of +/- 1 for better compression
+  // zero-flushing threshold: for later coefficients, round some values slightly larger than 0.5 to 0 instead of +/- 1 for better compression
   static const double zeroflush[] = {
     0x0.80p+0, 0x0.80p+0, 0x0.80p+0, 0x0.80p+0, 0x0.81p+0, 0x0.80p+0, 0x0.84p+0, 0x0.85p+0, 0x0.85p+0, 0x0.84p+0,
     0x0.88p+0, 0x0.89p+0, 0x0.8ap+0, 0x0.89p+0, 0x0.88p+0, 0x0.8cp+0, 0x0.8dp+0, 0x0.8ep+0, 0x0.8ep+0, 0x0.8dp+0,