Bump minimum libpng dependency to 1.6.32
Remove PNG_eXIf_SUPPORTED and PNG_iTXt_SUPPORTED conditionals in
avifpng.c to simplify the code and to avoid generating new PNGs
with legacy raw profile chunks.
Reject PNG export with XMP data containing any null character.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d3532ca..8f55f76 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
except XMP payloads larger than 65502 bytes in JPEG.
* The --grid flag in avifenc can be used for images that are not evenly divided
into cells.
+* Apps must be built with libpng version 1.6.32 or above.
## [0.11.1] - 2022-10-19
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3832320..e9a43ec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -504,7 +504,7 @@
if(AVIF_BUILD_APPS OR (AVIF_BUILD_TESTS AND AVIF_ENABLE_GTEST))
find_package(ZLIB REQUIRED)
- find_package(PNG REQUIRED)
+ find_package(PNG 1.6.32 REQUIRED) # 1.6.32 or above for png_get_eXIf_1()/png_set_eXIf_1() and iTXt (for XMP).
find_package(JPEG REQUIRED)
add_library(
diff --git a/apps/shared/avifpng.c b/apps/shared/avifpng.c
index ce01abe..c419427 100644
--- a/apps/shared/avifpng.c
+++ b/apps/shared/avifpng.c
@@ -14,6 +14,10 @@
#include <stdlib.h>
#include <string.h>
+#if !defined(PNG_eXIf_SUPPORTED) || !defined(PNG_iTXt_SUPPORTED)
+#error "libpng 1.6.32 or above with PNG_eXIf_SUPPORTED and PNG_iTXt_SUPPORTED is required."
+#endif
+
// See libpng-manual.txt, section XI.
#if PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5)
typedef png_bytep png_iccp_datap;
@@ -117,7 +121,6 @@
// Returns AVIF_FALSE in case of a parsing error.
static avifBool avifExtractExifAndXMP(png_structp png, png_infop info, avifBool * ignoreExif, avifBool * ignoreXMP, avifImage * avif)
{
-#ifdef PNG_eXIf_SUPPORTED
if (!*ignoreExif) {
png_uint_32 exifSize = 0;
png_bytep exif = NULL;
@@ -140,7 +143,6 @@
*ignoreExif = AVIF_TRUE; // Ignore any other Exif chunk.
}
}
-#endif // PNG_eXIf_SUPPORTED
// HEIF specification ISO-23008 section A.2.1 allows including and excluding the Exif\0\0 header from AVIF files.
// The PNG 1.5 extension mentions the omission of this header for the modern standard eXIf chunk.
@@ -154,11 +156,9 @@
const png_uint_32 numTextChunks = png_get_text(png, info, &text, NULL);
for (png_uint_32 i = 0; (!*ignoreExif || !*ignoreXMP) && (i < numTextChunks); ++i, ++text) {
png_size_t textLength = text->text_length;
-#ifdef PNG_iTXt_SUPPORTED
if ((text->compression == PNG_ITXT_COMPRESSION_NONE) || (text->compression == PNG_ITXT_COMPRESSION_zTXt)) {
textLength = text->itxt_length;
}
-#endif
if (!*ignoreExif && !strcmp(text->key, "Raw profile type exif")) {
if (!avifCopyRawProfile(text->text, textLength, &avif->exif)) {
@@ -387,30 +387,11 @@
//------------------------------------------------------------------------------
// Writing
-// Does the opposite of avifCopyRawProfile(): writes a payload as a raw profile string.
-static avifBool avifBytesToRawProfile(const avifRWData * bytes, const char * profileName, avifRWData * profile)
-{
- // The width of the profile length is 8 characters.
- if (bytes->size > 99999999) {
- return AVIF_FALSE;
- }
- size_t position = 1 + strlen(profileName) + 1 + 8 + 1;
- const size_t profileLength = position + bytes->size * 2 + 1;
- avifRWDataRealloc(profile, profileLength);
- snprintf((char *)profile->data, position + 1, "\n%s\n%08lu\n", profileName, (unsigned long)bytes->size);
- for (size_t i = 0; i < bytes->size; ++i, position += 2) {
- snprintf((char *)profile->data + position, 2 + 1, "%02x", bytes->data[i]);
- }
- profile->data[position] = '\n';
- return AVIF_TRUE;
-}
-
avifBool avifPNGWrite(const char * outputFilename, const avifImage * avif, uint32_t requestedDepth, avifChromaUpsampling chromaUpsampling, int compressionLevel)
{
volatile avifBool writeResult = AVIF_FALSE;
png_structp png = NULL;
png_infop info = NULL;
- avifRWData exif = { NULL, 0 };
avifRWData xmp = { NULL, 0 };
png_bytep * volatile rowPointers = NULL;
FILE * volatile f = NULL;
@@ -491,30 +472,19 @@
png_text texts[2];
int numTextMetadataChunks = 0;
if (avif->exif.data && (avif->exif.size > 0)) {
-#ifdef PNG_eXIf_SUPPORTED
if (avif->exif.size > UINT32_MAX) {
fprintf(stderr, "Error writing PNG: Exif metadata is too big\n");
goto cleanup;
}
png_set_eXIf_1(png, info, (png_uint_32)avif->exif.size, avif->exif.data);
-#else
- if (!avifBytesToRawProfile(&avif->exif, "Exif", &exif)) {
- fprintf(stderr, "Error writing PNG: Exif metadata is too big\n");
- goto cleanup;
- }
- png_text * text = &texts[numTextMetadataChunks++];
- memset(text, 0, sizeof(*text));
- text->compression = PNG_TEXT_COMPRESSION_zTXt;
- text->key = "Raw profile type exif";
- text->text = (char *)exif.data;
- text->text_length = exif.size;
-#endif // PNG_eXIf_SUPPORTED
}
if (avif->xmp.data && (avif->xmp.size > 0)) {
-#ifdef PNG_iTXt_SUPPORTED
// The iTXt XMP payload may not contain a zero byte according to section 4.2.3.3 of
- // the PNG specification, version 1.2. Otherwise, use a raw profile.
- if (!memchr(avif->xmp.data, '\0', avif->xmp.size)) {
+ // the PNG specification, version 1.2.
+ if (memchr(avif->xmp.data, '\0', avif->xmp.size)) {
+ fprintf(stderr, "Error writing PNG: XMP metadata contains an invalid null character\n");
+ goto cleanup;
+ } else {
// Providing the length through png_text.itxt_length does not work.
// The given png_text.text string must end with a zero byte.
if (avif->xmp.size >= SIZE_MAX) {
@@ -530,19 +500,6 @@
text->key = "XML:com.adobe.xmp";
text->text = (char *)xmp.data;
text->itxt_length = xmp.size;
- } else
-#endif // PNG_iTXt_SUPPORTED
- {
- if (!avifBytesToRawProfile(&avif->xmp, "XMP", &xmp)) {
- fprintf(stderr, "Error writing PNG: XMP metadata is too big\n");
- goto cleanup;
- }
- png_text * text = &texts[numTextMetadataChunks++];
- memset(text, 0, sizeof(*text));
- text->compression = PNG_TEXT_COMPRESSION_zTXt;
- text->key = "Raw profile type xmp";
- text->text = (char *)xmp.data;
- text->text_length = xmp.size;
}
}
if (numTextMetadataChunks != 0) {
@@ -583,7 +540,6 @@
if (png) {
png_destroy_write_struct(&png, &info);
}
- avifRWDataFree(&exif);
avifRWDataFree(&xmp);
if (rowPointers) {
free(rowPointers);
