metdata: more logging and code cleanups

Sprinkle more debug log statements into the code. Move some repeaded string
constant into header files and use sizeof instead of manually counted bytes. Add
comments.

1 files changed, 29 insertions, 31 deletions

diff --git a/ext/metadata/metadataparsejpeg.c b/ext/metadata/metadataparsejpeg.c
index 8e90b5c7..0fe52017 100644
--- a/ext/metadata/metadataparsejpeg.c
+++ b/ext/metadata/metadataparsejpeg.c
@@ -82,9 +82,12 @@
 
 #include "metadataparsejpeg.h"
 #include "metadataparseutil.h"
+#include "metadataexif.h"
+#include "metadataxmp.h"
 
 #ifdef HAVE_IPTC
 #include <libiptcdata/iptc-jpeg.h>
+#include "metadataiptc.h"
 #endif
 
 /*
@@ -226,9 +229,7 @@ metadataparse_jpeg_parse (JpegParseData * jpeg_data, guint8 * buf,
     guint32 * bufsize, const guint32 offset, guint8 ** next_start,
     guint32 * next_size)
 {
-
   int ret = META_PARSING_DONE;
-  guint8 mark[2] = { 0x00, 0x00 };
   const guint8 *step_buf = buf;
 
   /* step_buf holds where buf starts. this const value will be passed to
@@ -240,6 +241,7 @@ metadataparse_jpeg_parse (JpegParseData * jpeg_data, guint8 * buf,
   *next_start = buf;
 
   if (jpeg_data->state == JPEG_PARSE_NULL) {
+    guint8 mark[2];
 
     /* only the first time this function is called it will verify the stream
        type to be sure it is a JPEG */
@@ -259,9 +261,7 @@ metadataparse_jpeg_parse (JpegParseData * jpeg_data, guint8 * buf,
       ret = META_PARSING_ERROR;
       goto done;
     }
-
     jpeg_data->state = JPEG_PARSE_READING;
-
   }
 
   while (ret == META_PARSING_DONE) {
@@ -309,9 +309,8 @@ metadataparse_jpeg_parse (JpegParseData * jpeg_data, guint8 * buf,
   }
 
 done:
-
+  GST_INFO ("finishing: %d", ret);
   return ret;
-
 }
 
 /*
@@ -389,12 +388,6 @@ metadataparse_jpeg_reading (JpegParseData * jpeg_data, guint8 ** buf,
   guint16 chunk_size = 0;
 
   static const char JfifHeader[] = "JFIF";
-  static const unsigned char ExifHeader[] =
-      { 0x45, 0x78, 0x69, 0x66, 0x00, 0x00 };
-#ifdef HAVE_IPTC
-  static const char PhotoshopHeader[] = "Photoshop 3.0";
-#endif
-  static const char XmpHeader[] = "http://ns.adobe.com/xap/1.0/";
 
   *next_start = *buf;
 
@@ -407,12 +400,14 @@ metadataparse_jpeg_reading (JpegParseData * jpeg_data, guint8 ** buf,
   mark[0] = READ (*buf, *bufsize);
   mark[1] = READ (*buf, *bufsize);
 
+  GST_DEBUG ("parsing JPEG marker : 0x%02x%02x", mark[0], mark[1]);
+
   if (mark[0] == 0xFF) {
-    if (mark[1] == 0xD9) {      /* end of image */
+    if (mark[1] == 0xD9) {      /* EOI - end of image */
       ret = META_PARSING_DONE;
       jpeg_data->state = JPEG_PARSE_DONE;
       goto done;
-    } else if (mark[1] == 0xDA) {
+    } else if (mark[1] == 0xDA) {       /* SOS - start of scan */
       /* start of scan image, lets not look behind of this */
       ret = META_PARSING_DONE;
       jpeg_data->state = JPEG_PARSE_DONE;
@@ -428,30 +423,34 @@ metadataparse_jpeg_reading (JpegParseData * jpeg_data, guint8 ** buf,
     chunk_size = READ (*buf, *bufsize) << 8;
     chunk_size += READ (*buf, *bufsize);
 
-    if (mark[1] == 0xE0) {      /* may be JFIF */
+    if (mark[1] == 0xE0) {      /* APP0 - may be JFIF */
 
-      if (chunk_size >= 16) {
+      /* FIXME: whats the 14 ? according to
+       * http://en.wikipedia.org/wiki/JFIF#JFIF_segment_format
+       * its the jfif segment without thumbnails
+       */
+      if (chunk_size >= 14 + 2) {
         if (*bufsize < 14) {
           *next_size = (*buf - *next_start) + 14;
           ret = META_PARSING_NEED_MORE_DATA;
           goto done;
         }
 
-        if (0 == memcmp (JfifHeader, *buf, 5)) {
+        if (0 == memcmp (JfifHeader, *buf, sizeof (JfifHeader))) {
           jpeg_data->jfif_found = TRUE;
         }
       }
 
-    } else if (mark[1] == 0xE1) {       /* may be it is Exif or XMP */
+    } else if (mark[1] == 0xE1) {       /* APP1 - may be it is Exif or XMP */
 
-      if (chunk_size >= 8) {    /* size2 'EXIF' 0x00 0x00 */
-        if (*bufsize < 6) {
-          *next_size = (*buf - *next_start) + 6;
+      if (chunk_size >= sizeof (EXIF_HEADER) + 2) {
+        if (*bufsize < sizeof (EXIF_HEADER)) {
+          *next_size = (*buf - *next_start) + sizeof (EXIF_HEADER);
           ret = META_PARSING_NEED_MORE_DATA;
           goto done;
         }
 
-        if (0 == memcmp (ExifHeader, *buf, 6)) {
+        if (0 == memcmp (EXIF_HEADER, *buf, sizeof (EXIF_HEADER))) {
           MetadataChunk chunk;
 
           if (!jpeg_data->parse_only) {
@@ -502,14 +501,14 @@ metadataparse_jpeg_reading (JpegParseData * jpeg_data, guint8 ** buf,
             goto done;
           }
         }
-        if (chunk_size >= 31) { /* size2 "http://ns.adobe.com/xap/1.0/" */
-          if (*bufsize < 29) {
-            *next_size = (*buf - *next_start) + 29;
+        if (chunk_size >= sizeof (XMP_HEADER) + 2) {
+          if (*bufsize < sizeof (XMP_HEADER)) {
+            *next_size = (*buf - *next_start) + sizeof (XMP_HEADER);
             ret = META_PARSING_NEED_MORE_DATA;
             goto done;
           }
 
-          if (0 == memcmp (XmpHeader, *buf, 29)) {
+          if (0 == memcmp (XMP_HEADER, *buf, sizeof (XMP_HEADER))) {
 
             if (!jpeg_data->parse_only) {
 
@@ -527,9 +526,9 @@ metadataparse_jpeg_reading (JpegParseData * jpeg_data, guint8 ** buf,
 
             /* if adapter has been provided, prepare to hold chunk */
             if (jpeg_data->xmp_adapter) {
-              *buf += 29;
-              *bufsize -= 29;
-              jpeg_data->read = chunk_size - 2 - 29;
+              *buf += sizeof (XMP_HEADER);
+              *bufsize -= sizeof (XMP_HEADER);
+              jpeg_data->read = chunk_size - 2 - sizeof (XMP_HEADER);
               jpeg_data->state = JPEG_PARSE_XMP;
               ret = META_PARSING_DONE;
               goto done;
@@ -550,8 +549,7 @@ metadataparse_jpeg_reading (JpegParseData * jpeg_data, guint8 ** buf,
           goto done;
         }
 
-
-        if (0 == memcmp (PhotoshopHeader, *buf, 14)) {
+        if (0 == memcmp (PHOTOSHOP_HEADER, *buf, sizeof (PHOTOSHOP_HEADER))) {
 
           if (!jpeg_data->parse_only) {