1 files changed, 54 insertions, 22 deletions

diff --git a/firmware/id3.c b/firmware/id3.c
index 184bdb5725..a0dda92eb9 100644
--- a/firmware/id3.c
+++ b/firmware/id3.c
@@ -400,8 +400,6 @@ static int parseuser( struct mp3entry* entry, char* tag, int bufferpos )
     int desc_len = strlen(tag);
     int value_len = 0;
 
-    /* Note: for ID3v2.4, parse_replaygain will not overwrite replaygain
-       values already parsed from RVA2 tags */
     if ((tag - entry->id3v2buf + desc_len + 2) < bufferpos) {
         /* At least part of the value was read, so we can safely try to
          * parse it
@@ -411,37 +409,71 @@ static int parseuser( struct mp3entry* entry, char* tag, int bufferpos )
             bufferpos - (tag - entry->id3v2buf));
     }
 
-    if (value_len) {
-        bufferpos = tag - entry->id3v2buf + value_len;
-    } else {
-        bufferpos = tag - entry->id3v2buf;
-    }
-
-    return bufferpos;
+    return tag - entry->id3v2buf + value_len;
 }
 
 /* parse RVA2 binary data and convert to replaygain information. */
 static int parserva2( struct mp3entry* entry, char* tag, int bufferpos )
 {
-    char* value = NULL;
     int desc_len = strlen(tag);
+    int end_pos = tag - entry->id3v2buf + desc_len + 5;
     int value_len = 0;
+    unsigned char* value = tag + desc_len + 1;
 
-    /* Only parse RVA2 replaygain tags if tag version == 2.4 */
-    if (entry->id3version == ID3_VER_2_4 &&
-        (tag - entry->id3v2buf + desc_len + 2) < bufferpos) {
-        value = tag + desc_len + 1;
-        value_len = parse_replaygain_rva(tag, value, entry, tag,
-            bufferpos - (tag - entry->id3v2buf));
-    }
+    /* Only parse RVA2 replaygain tags if tag version == 2.4 and channel
+     * type is master volume.
+     */
+    if (entry->id3version == ID3_VER_2_4 && end_pos < bufferpos 
+            && *value++ == 1) {
+        long gain = 0;
+        long peak = 0;
+        long peakbits;
+        long peakbytes;
+        bool album = false;
+
+        /* The RVA2 specification is unclear on some things (id string and
+         * peak volume), but this matches how Quod Libet use them.
+         */
+            
+        gain = (int16_t) ((value[0] << 8) | value[1]);
+        value += 2;
+        peakbits = *value++;
+        peakbytes = (peakbits + 7) / 8;
+    
+        /* Only use the topmost 24 bits for peak volume */
+        if (peakbytes > 3) {
+            peakbytes = 3;
+        }
 
-    if (value_len) {
-        bufferpos = tag - entry->id3v2buf + value_len;
-    } else {
-        bufferpos = tag - entry->id3v2buf;
+        /* Make sure the peak bits were read */
+        if (end_pos + peakbytes < bufferpos) {
+            long shift = ((8 - (peakbits & 7)) & 7) + (3 - peakbytes) * 8;
+
+            for ( ; peakbytes; peakbytes--) {
+                peak <<= 8;
+                peak += *value++;
+            }
+    
+            peak <<= shift;
+    
+            if (peakbits > 24) {
+                peak += *value >> (8 - shift);
+            }
+        }
+    
+        if (strcasecmp(tag, "album") == 0) {
+            album = true;
+        } else if (strcasecmp(tag, "track") != 0) {
+            gain = 0;
+        }
+            
+        if (gain) {
+            value_len = parse_replaygain_int(album, gain, peak * 2, entry, 
+                tag, sizeof(entry->id3v2buf) - (tag - entry->id3v2buf));
+        }
     }
 
-    return bufferpos;
+    return tag - entry->id3v2buf + value_len;
 }
 #endif