metadata: mp3: Support unsync embedded jpeg album art

Support parsing alubm art from id3 metadata with "unsynchronisation scheme":
https://id3.org/id3v2.3.0#The_unsynchronisation_scheme

Change-Id: I1e2ca4ae0aa967f7e80142a04c9a7d99e38e68b2

apps/buffering.c

@@ -867,7 +867,7 @@ static int load_image(int fd, const char *path,
 #ifdef HAVE_JPEG
     if (aa != NULL) {
         lseek(fd, aa->pos, SEEK_SET);
-        rc = clip_jpeg_fd(fd, aa->size, bmp, (int)max_size, format, NULL);
+        rc = clip_jpeg_fd(fd, aa->type, aa->size, bmp, (int)max_size, format, NULL);
     }
     else if (strcmp(path + strlen(path) - 4, ".bmp"))
         rc = read_jpeg_fd(fd, bmp, (int)max_size, format, NULL);

apps/playback.c

@@ -1922,7 +1922,7 @@ static int audio_load_albumart(struct track_info *infop,
         /* We can only decode jpeg for embedded AA */
         if (global_settings.album_art != AA_OFF &&
             hid < 0 && hid != ERR_BUFFER_FULL &&
-            track_id3->has_embedded_albumart && track_id3->albumart.type == AA_TYPE_JPG)
+            track_id3->has_embedded_albumart && (track_id3->albumart.type & AA_CLEAR_FLAGS_MASK) == AA_TYPE_JPG)
         {
             if (is_current_track)
                 clear_last_folder_album_art();

apps/recorder/jpeg_load.c

@@ -26,7 +26,7 @@
 * KIND, either express or implied.
 *
 ****************************************************************************/
-
+#include "embedded_metadata.h"
 #include "plugin.h"
 #include "debug.h"
 #include "jpeg_load.h"
@@ -79,6 +79,9 @@ struct jpeg
     int fd;
     int buf_left;
     int buf_index;
+
+    int (*read_buf)(struct jpeg* p_jpeg, size_t count);
+    void* custom_param;
 #endif
     unsigned long len;
     unsigned long int bitbuf;
@@ -872,11 +875,21 @@ INLINE void jpeg_putc(struct jpeg* p_jpeg)
     p_jpeg->data--;
 }
 #else
+
+static int read_buf(struct jpeg* p_jpeg, size_t count)
+{
+    return read(p_jpeg->fd, p_jpeg->buf, count);
+}
+
+static int read_buf_id3_unsync(struct jpeg* p_jpeg, size_t count)
+{
+    count = read(p_jpeg->fd, p_jpeg->buf, count);
+    return id3_unsynchronize(p_jpeg->buf, count, (bool*) &p_jpeg->custom_param);
+}
+
 INLINE void fill_buf(struct jpeg* p_jpeg)
 {
-        p_jpeg->buf_left = read(p_jpeg->fd, p_jpeg->buf,
-                                (p_jpeg->len >= JPEG_READ_BUF_SIZE)?
-                                     JPEG_READ_BUF_SIZE : p_jpeg->len);
+        p_jpeg->buf_left = p_jpeg->read_buf(p_jpeg, MIN(JPEG_READ_BUF_SIZE, p_jpeg->len));
         p_jpeg->buf_index = 0;
         if (p_jpeg->buf_left > 0)
             p_jpeg->len -= p_jpeg->buf_left;
@@ -1958,7 +1971,7 @@ int clip_jpeg_file(const char* filename,
         return fd * 10 - 1;
     }
     lseek(fd, offset, SEEK_SET);
-    ret = clip_jpeg_fd(fd, jpeg_size, bm, maxsize, format, cformat);
+    ret = clip_jpeg_fd(fd, 0, jpeg_size, bm, maxsize, format, cformat);
     close(fd);
     return ret;
 }
@@ -2007,7 +2020,7 @@ int get_jpeg_dim_mem(unsigned char *data, unsigned long len,
 
 int decode_jpeg_mem(unsigned char *data,
 #else
-int clip_jpeg_fd(int fd,
+int clip_jpeg_fd(int fd, int flags,
 #endif
                  unsigned long len,
                  struct bitmap *bm,
@@ -2038,6 +2051,14 @@ int clip_jpeg_fd(int fd,
     p_jpeg->fd = fd;
     if (p_jpeg->len == 0)
         p_jpeg->len = filesize(p_jpeg->fd);
+
+    p_jpeg->read_buf = read_buf;
+
+    if (flags & AA_FLAG_ID3_UNSYNC)
+    {
+        p_jpeg->read_buf = read_buf_id3_unsync;
+        p_jpeg->custom_param = false;
+    }
 #endif
     status = process_markers(p_jpeg);
 #ifndef JPEG_FROM_MEM
@@ -2225,7 +2246,7 @@ int read_jpeg_fd(int fd,
                  int format,
                  const struct custom_format *cformat)
 {
-    return clip_jpeg_fd(fd, 0, bm, maxsize, format, cformat);
+    return clip_jpeg_fd(fd, 0, 0, bm, maxsize, format, cformat);
 }
 #endif
 

apps/recorder/jpeg_load.h

@@ -67,7 +67,7 @@ int clip_jpeg_file(const char* filename,
  * read embedded jpeg files as above. Needs an open file descripter, and
  * assumes the caller has lseek()'d to the start of the jpeg blob
  **/
-int clip_jpeg_fd(int fd,
+int clip_jpeg_fd(int fd, int flags,
                  unsigned long jpeg_size,
                  struct bitmap *bm,
                  int maxsize,

lib/rbcodec/metadata/embedded_metadata.h

@@ -0,0 +1,23 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2024 Roman Artiukhin
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include <stdbool.h>
+
+int id3_unsynchronize(char* tag, int len, bool *ff_found);

lib/rbcodec/metadata/id3tags.c

@@ -45,6 +45,7 @@
 #include "mp3data.h"
 #include "metadata_common.h"
 #include "metadata_parsers.h"
+#include "embedded_metadata.h"
 #include "misc.h"
 
 static unsigned long unsync(unsigned long b0,
@@ -161,7 +162,8 @@ struct tag_resolver {
 
 static bool global_ff_found;
 
-static int unsynchronize(char* tag, int len, bool *ff_found)
+#define unsynchronize id3_unsynchronize
+int id3_unsynchronize(char* tag, int len, bool *ff_found)
 {
     int i;
     unsigned char c;
@@ -299,9 +301,7 @@ static int parsealbumart( struct mp3entry* entry, char* tag, int bufferpos )
     if(entry->has_embedded_albumart)
         return bufferpos;
 
-    /* we currently don't support unsynchronizing albumart */
-    if (entry->albumart.type == AA_TYPE_UNSYNC)
-        return bufferpos;
+    bool unsync = entry->albumart.type == AA_FLAG_ID3_UNSYNC;
 
     entry->albumart.type = AA_TYPE_UNKNOWN;
 
@@ -353,6 +353,10 @@ static int parsealbumart( struct mp3entry* entry, char* tag, int bufferpos )
         /* fixup offset&size for image data */
         entry->albumart.pos  += tag - start;
         entry->albumart.size -= tag - start;
+        if (unsync)
+        {
+            entry->albumart.type |= AA_FLAG_ID3_UNSYNC;
+        }
         /* check for malformed tag with no picture data */
         entry->has_embedded_albumart = (entry->albumart.size != 0);
     }
@@ -1142,14 +1146,11 @@ retry_with_limit:
                     ((tr->tag_length == 4 && !memcmp( header, "APIC", 4)) ||
                      (tr->tag_length == 3 && !memcmp( header, "PIC" , 3))))
                 {
-                    if (unsynch || (global_unsynch && version <= ID3_VER_2_3))
-                        entry->albumart.type = AA_TYPE_UNSYNC;
-                    else
-                    {
-                        entry->albumart.pos = lseek(fd, 0, SEEK_CUR) - framelen;
-                        entry->albumart.size = totframelen;
-                        entry->albumart.type = AA_TYPE_UNKNOWN;
-                    }
+                    entry->albumart.pos = lseek(fd, 0, SEEK_CUR) - framelen;
+                    entry->albumart.size = totframelen;
+                    entry->albumart.type = (unsynch || (global_unsynch && version <= ID3_VER_2_3))
+                                           ? AA_FLAG_ID3_UNSYNC
+                                           : AA_TYPE_UNKNOWN;
                 }
 #endif
                 if( tr->ppFunc )

lib/rbcodec/metadata/metadata.h

@@ -196,13 +196,17 @@ enum {
     ID3_VER_2_4
 };
 
+#define AA_FLAGS_SHIFT 4
+#define AA_CLEAR_FLAGS_MASK ~(-1 << AA_FLAGS_SHIFT)
+
 #ifdef HAVE_ALBUMART
 enum mp3_aa_type {
-    AA_TYPE_UNSYNC = -1,
     AA_TYPE_UNKNOWN,
     AA_TYPE_BMP,
     AA_TYPE_PNG,
     AA_TYPE_JPG,
+
+    AA_FLAG_ID3_UNSYNC = 1 << (AA_FLAGS_SHIFT + 0),
 };
 
 struct mp3_albumart {