ref: 4a5897265a9a7d1f0aa5c2e62ab1d208dc6c1348
parent: d0fa4337002a47a95efa5492ea44a2f9ac4b27f0
author: Timothy B. Terriberry <tterribe@xiph.org>
date: Sat Apr 27 08:33:27 EDT 2013
Add METADATA_BLOCK_PICTURE validation to opusinfo. This will parse such comments and validate the various pieces, and print the results in a form similar to that used by the --picture argument to opusenc.
--- a/src/opusinfo.c
+++ b/src/opusinfo.c
@@ -97,6 +97,47 @@
va_end(ap);
}
+/*A version of strncasecmp() that is guaranteed to only ignore the case of
+ ASCII characters.*/
+static int oi_strncasecmp(const char *a, const char *b, int n){+ int i;
+ for (i = 0; i < n; i++) {+ int aval;
+ int bval;
+ int diff;
+ aval = a[i];
+ bval = b[i];
+ if(aval >= 'a' && aval <= 'z') {+ aval -= 'a'-'A';
+ }
+ if(bval >= 'a' && bval <= 'z') {+ bval -= 'a'-'A';
+ }
+ diff = aval-bval;
+ if(diff) {+ return diff;
+ }
+ }
+ return 0;
+}
+
+#define READ_U32_BE(buf) \
+ (((buf)[0]<<24)|((buf)[1]<<16)|((buf)[2]<<8)|((buf)[3]&0xff))
+
+static int is_jpeg(const unsigned char *buf, size_t length){+ return length >= 11 && memcmp(buf, "\xFF\xD8\xFF\xE0", 4) == 0
+ && (buf[4]<<8|buf[5]) >= 16 && memcmp(buf+6, "JFIF", 5) == 0;
+}
+
+static int is_png(const unsigned char *buf, size_t length){+ return length >= 8 && memcmp(buf, "\x89PNG\x0D\x0A\x1A\x0A", 8) == 0;
+}
+
+static int is_gif(const unsigned char *buf, size_t length){+ return length >= 6
+ && (memcmp(buf, "GIF87a", 6) == 0 || memcmp(buf, "GIF89a", 6) == 0);
+}
+
void check_xiph_comment(stream_processor *stream, int i, const char *comment,
int comment_length)
{@@ -125,7 +166,7 @@
}
if(broken)
- return;
+ return;
val = (unsigned char *)comment;
@@ -250,6 +291,273 @@
j += bytes;
}
+ if(sep - comment == 22
+ && oi_strncasecmp(comment, "METADATA_BLOCK_PICTURE", 22) == 0) {+ ogg_uint32_t picture_type;
+ ogg_uint32_t mime_type_length;
+ ogg_uint32_t description_length;
+ ogg_uint32_t width;
+ ogg_uint32_t height;
+ ogg_uint32_t depth;
+ ogg_uint32_t colors;
+ ogg_uint32_t image_length;
+ unsigned char *data;
+ int data_sz;
+ int len;
+ int is_url;
+ len=comment_length - (sep+1-comment);
+ /*Decode the Base64 encoded data.*/
+ if(len&3) {+ oi_warn(_("WARNING: Illegal Base64 length in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): %i is not "
+ "divisible by 4\n"), i, stream->num, len);
+ }
+ len>>=2;
+ data_sz=3*len;
+ if(data_sz > 0) {+ if(comment[comment_length - 1] == '=') {+ data_sz--;
+ }
+ if(comment[comment_length - 2] == '=') {+ data_sz--;
+ }
+ }
+ data=(unsigned char *)malloc(data_sz*sizeof(*data));
+ for (j = 0; j < len; j++) {+ ogg_uint32_t value;
+ int k;
+ value = 0;
+ for (k = 1; k <= 4; k++) {+ unsigned c;
+ unsigned d;
+ c = (unsigned char)sep[4*j+k];
+ if(c == '+') {+ d = 62;
+ }
+ else if(c == '/') {+ d = 63;
+ }
+ else if(c >= '0' && c <= '9') {+ d = 52+c-'0';
+ }
+ else if(c >= 'a' && c <= 'z') {+ d = 26+c-'a';
+ }
+ else if(c >= 'A' && c <= 'Z') {+ d = c-'A';
+ }
+ else if(c == '=') {+ if(3*j+k-1 < data_sz) {+ oi_warn(_("WARNING: Terminating '=' in illegal "+ "position in Base64 encoded "
+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "%i characters before the end.\n"), i,
+ stream->num, data_sz - (3*j+k-1));
+ free(data);
+ return;
+ }
+ d = 0;
+ }
+ else {+ oi_warn(_("WARNING: Illegal Base64 character in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "'%c'\n"), i, stream->num, (char)c);
+ free(data);
+ return;
+ }
+ value = value << 6 | d;
+ }
+ data[3*j] = (unsigned char)(value>>16);
+ if(3*j+1 < data_sz) {+ data[3*j+1] = (unsigned char)(value>>8);
+ if(3*j+2 < data_sz) {+ data[3*j+2] = (unsigned char)value;
+ }
+ }
+ }
+ /*Now validate the METADATA_BLOCK_PICTURE structure.*/
+ if(data_sz < 32) {+ oi_warn(_("WARNING: Not enough data for "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "expected at least 32 bytes, got %i\n"), i, stream->num,
+ data_sz);
+ free(data);
+ return;
+ }
+ j = 0;
+ picture_type = READ_U32_BE(data+j);
+ if(picture_type > 20) {+ oi_warn(_("WARNING: Unknown picture type in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "%li\n"), i, stream->num, (long)picture_type);
+ free(data);
+ return;
+ }
+ if(picture_type >= 1 && picture_type <= 2) {+ if(stream->seen_file_icons & picture_type) {+ oi_warn(_("WARNING: Duplicate picture type in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ " %s\n"), i, stream->num, picture_type == 1 ?
+ _("only one picture of type 1 (32x32 icon) allowed") :+ _("only one picture of type 2 (icon) allowed"));+ free(data);
+ return;
+ }
+ stream->seen_file_icons |= picture_type;
+ }
+ j += 4;
+ mime_type_length = READ_U32_BE(data+j);
+ if(mime_type_length > (size_t)data_sz-32) {+ oi_warn(_("WARNING: Invalid mime type length in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "%lu bytes when %i are available\n"), i, stream->num,
+ (long)mime_type_length, data_sz-32);
+ free(data);
+ return;
+ }
+ for (j += 4; j < 8+(int)mime_type_length; j++) {+ if(data[j] < 0x20 || data[j] > 0x7E) {+ oi_warn(_("WARNING: Invalid character in mime type of "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "0x%02X\n"), i, stream->num, data[j]);
+ free(data);
+ return;
+ }
+ }
+ description_length = READ_U32_BE(data+j);
+ if(description_length > (size_t)data_sz-mime_type_length-32) {+ oi_warn(_("WARNING: Invalid description length in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "%lu bytes when %i are available\n"), i, stream->num,
+ (long)description_length, data_sz-mime_type_length-32);
+ free(data);
+ return;
+ }
+ /*TODO: Validate that description is UTF-8.*/
+ j += 4+description_length;
+ width = READ_U32_BE(data+j);
+ j += 4;
+ height = READ_U32_BE(data+j);
+ j += 4;
+ depth = READ_U32_BE(data+j);
+ j += 4;
+ colors = READ_U32_BE(data+j);
+ j += 4;
+ /*This isn't triggered if colors == 0, since that can be a valid
+ value.*/
+ if((width == 0 || height == 0 || depth == 0)
+ && (width != 0 || height != 0 || depth != 0 || colors != 0)) {+ oi_warn(_("WARNING: Invalid picture parameters in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "width (%i), height (%i), depth (%i), and colors (%i) MUST "
+ "either be set to valid values or all set to 0\n"), i,
+ stream->num, (int)width, (int)height, (int)depth,
+ (int)colors);
+ free(data);
+ return;
+ }
+ image_length = READ_U32_BE(data+j);
+ j += 4;
+ /*This one should match exactly.*/
+ if(image_length != (size_t)data_sz-j) {+ oi_warn(_("WARNING: Invalid image data size in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "%lu bytes when %i are available\n"), i, stream->num,
+ (long)image_length, data_sz-j);
+ free(data);
+ return;
+ }
+ is_url = 0;
+ if(mime_type_length == 10
+ && oi_strncasecmp((const char*)data+8, "image/jpeg",
+ mime_type_length) == 0) {+ if(!is_jpeg(data+j, image_length)) {+ oi_warn(_("WARNING: Invalid image data in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "mime type is %.*s but image does not appear to be "
+ "JPEG\n"), i, stream->num, mime_type_length, data+8);
+ free(data);
+ return;
+ }
+ }
+ else if(mime_type_length == 9
+ && oi_strncasecmp((const char *)data+8, "image/png",
+ mime_type_length) == 0) {+ if(!is_png(data+j, image_length)) {+ oi_warn(_("WARNING: Invalid image data in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "mime type is %.*s but image does not appear to be "
+ "PNG\n"), i, stream->num, mime_type_length, data+8);
+ free(data);
+ return;
+ }
+ }
+ else if(mime_type_length == 9
+ && oi_strncasecmp((const char *)data+8, "image/gif",
+ mime_type_length) == 0) {+ if(!is_gif(data+j, image_length)) {+ oi_warn(_("WARNING: Invalid image data in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "mime type is %.*s but image does not appear to be "
+ "PNG\n"), i, stream->num, mime_type_length, data+8);
+ free(data);
+ return;
+ }
+ }
+ else if(mime_type_length == 3
+ && strncmp((const char *)data+8, "-->", mime_type_length) == 0) {+ is_url = 1;
+ /*TODO: validate URL.*/
+ }
+ else if(mime_type_length > 0 && (mime_type_length != 6 ||
+ oi_strncasecmp((const char *)data+8, "image/",
+ mime_type_length) != 0)) {+ oi_warn(_("WARNING: Unknown mime type in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "\"%.*s\" may not be well-supported\n"), i, stream->num,
+ mime_type_length, data+8);
+ }
+ /*TODO: Extract width/height/depth/colors from image and compare to
+ encoded values. See code in opusenc.c*/
+ if(picture_type == 1
+ && (width != 0 && (width != 32 || height != 32))) {+ oi_warn(_("WARNING: Invalid picture in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "picture of type 1 (32x32 icon) MUST be a 32x32 PNG, but "
+ "the image has dimensions %ux%u\n"), i, stream->num,
+ (unsigned)width, (unsigned)height);
+ free(data);
+ return;
+ }
+ if(picture_type == 1 && !is_url && !is_png(data+j, image_length)) {+ oi_warn(_("WARNING: Invalid picture in "+ "METADATA_BLOCK_PICTURE comment %d (stream %d): "
+ "picture of type 1 (32x32 icon) MUST be a 32x32 PNG, but "
+ "the image does not appear to be a PNG\n"), i, stream->num);
+ free(data);
+ return;
+ }
+ /*Print the contents of the block using the same format as the
+ SPECIFICATION argument to opusenc/flac/etc. (except without an image
+ filename, since we don't know the original).*/
+ oi_info("\t%.*s%u|%.*s|%.*s|%ux%ux%u",+ sep+1-comment, comment, (unsigned)picture_type,
+ mime_type_length, data+8,
+ description_length, data+12+mime_type_length,
+ (unsigned)width, (unsigned)height, (unsigned)depth);
+ if(colors) {+ oi_info("/%u", (unsigned)colors);+ }
+ if(is_url) {+ oi_info("|%.*s\n", image_length, data+j);+ }
+ else {+ oi_info("|<%u bytes of image data>\n",(unsigned)image_length);+ }
+ free(data);
+ return;
+ }
+
if(!broken) { oi_info("\t%s\n", comment);}
@@ -375,6 +683,7 @@
stream->isnew = 1;
stream->isillegal = invalid;
stream->constraint_violated = constraint;
+ stream->seen_file_icons = 0;
{int res;
--- a/src/opusinfo.h
+++ b/src/opusinfo.h
@@ -24,6 +24,7 @@
int isnew;
long seqno;
int lostseq;
+ int seen_file_icons;
int start;
int end;