Fix FS8069, because Nico_P made it easy

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15840 a1c6a512-1295-4272-9138-f99709370657

apps/buffering.c

@@ -657,6 +657,7 @@ static bool buffer_handle(int handle_id)
         /* finished buffering the file */
         close(h->fd);
         h->fd = -1;
+        call_buffering_callbacks(EVENT_HANDLE_FINISHED, h->id);
     }
 
     return true;
@@ -1138,6 +1139,58 @@ ssize_t bufgetdata(int handle_id, size_t size, void **data)
     return size;
 }
 
+ssize_t bufgettail(int handle_id, size_t size, void **data)
+{
+    size_t tidx;
+
+    const struct memory_handle *h;
+    
+    h = find_handle(handle_id);
+
+    if (!h)
+        return ERR_HANDLE_NOT_FOUND;
+
+    if (h->filerem)
+        return ERR_HANDLE_NOT_DONE;
+
+    /* We don't support tail requests of > guardbuf_size, for simplicity */
+    if (size > GUARD_BUFSIZE)
+        return ERR_INVALID_VALUE;
+
+    tidx = RINGBUF_SUB(h->widx, size);
+
+    if (tidx + size > buffer_len)
+    {
+        size_t copy_n = tidx + size - buffer_len;
+        memcpy(guard_buffer, (unsigned char *)buffer, copy_n);
+    }
+
+    *data = &buffer[tidx];
+    return size;
+}
+
+ssize_t bufcuttail(int handle_id, size_t size)
+{
+    struct memory_handle *h;
+    
+    h = find_handle(handle_id);
+
+    if (!h)
+        return ERR_HANDLE_NOT_FOUND;
+
+    if (h->filerem)
+        return ERR_HANDLE_NOT_DONE;
+
+    if (h->available < size)
+        size = h->available;
+
+    h->available -= size;
+    h->filesize -= size;
+    h->widx = RINGBUF_SUB(h->widx, size);
+    return size;
+}
+
+
 /*
 SECONDARY EXPORTED FUNCTIONS
 ============================

apps/buffering.h

@@ -41,6 +41,7 @@ enum callback_event {
     EVENT_HANDLE_REBUFFER,
     EVENT_HANDLE_CLOSED,
     EVENT_HANDLE_MOVED,
+    EVENT_HANDLE_FINISHED,
 };
 
 /* Error return values */
@@ -48,6 +49,7 @@ enum callback_event {
 #define ERR_BUFFER_FULL         -2
 #define ERR_INVALID_VALUE       -3
 #define ERR_FILE_ERROR          -4
+#define ERR_HANDLE_NOT_DONE     -5
 
 
 /* Initialise the buffering subsystem */
@@ -68,9 +70,12 @@ bool buffering_reset(char *buf, size_t buflen);
  * bufadvance: Move handle reading index, relatively to current position
  * bufread   : Copy data from a handle to a buffer
  * bufgetdata: Obtain a pointer for linear access to a "size" amount of data
+ * bufgettail: Out-of-band get the last size bytes of a handle.
+ * bufcuttail: Out-of-band remove the trailing 'size' bytes of a handle.
  *
  * NOTE: bufread and bufgetdata will block the caller until the requested
  * amount of data is ready (unless EOF is reached).
+ * NOTE: Tail operations are only legal when the end of the file is buffered.
  ****************************************************************************/
 
 #define BUF_MAX_HANDLES         256
@@ -82,6 +87,8 @@ int bufseek(int handle_id, size_t newpos);
 int bufadvance(int handle_id, off_t offset);
 ssize_t bufread(int handle_id, size_t size, void *dest);
 ssize_t bufgetdata(int handle_id, size_t size, void **data);
+ssize_t bufgettail(int handle_id, size_t size, void **data);
+ssize_t bufcuttail(int handle_id, size_t size);
 
 
 /***************************************************************************

apps/metadata.c

@@ -30,6 +30,9 @@
 
 #if CONFIG_CODEC == SWCODEC
 
+/* For trailing tag stripping */
+#include "buffering.h"
+
 #include "metadata/metadata_common.h"
 #include "metadata/metadata_parsers.h"
 
@@ -322,3 +325,42 @@ bool get_metadata(struct mp3entry* id3, int fd, const char* trackname)
     return true;
 }
 
+void strip_tags(int handle_id)
+{
+    int i;
+    static const unsigned char tag[] = "TAG";
+    static const unsigned char apetag[] = "APETAGEX";    
+    size_t len, version;
+    unsigned char *tail;
+
+    if (bufgettail(handle_id, 128, (void **)&tail) != 128)
+        return;
+
+    for(i = 0;i < 3;i++)
+        if(tail[i] != tag[i])
+            goto strip_ape_tag;
+
+    /* Skip id3v1 tag */
+    logf("Cutting off ID3v1 tag");
+    bufcuttail(handle_id, 128);
+
+strip_ape_tag:
+    /* Check for APE tag (look for the APE tag footer) */
+
+    if (bufgettail(handle_id, 32, (void **)&tail) != 32)
+        return;
+
+    for(i = 0;i < 8;i++)
+        if(tail[i] != apetag[i])
+            return;
+
+    /* Read the version and length from the footer */
+    version = tail[8] | (tail[9] << 8) | (tail[10] << 16) | (tail[11] << 24);
+    len = tail[12] | (tail[13] << 8) | (tail[14] << 16) | (tail[15] << 24);
+    if (version == 2000)
+        len += 32; /* APEv2 has a 32 byte header */
+
+    /* Skip APE tag */
+    logf("Cutting off APE tag (%ldB)", len);
+    bufcuttail(handle_id, len);
+}

apps/metadata.h

@@ -24,6 +24,7 @@
 
 unsigned int probe_file_format(const char *filename);
 bool get_metadata(struct mp3entry* id3, int fd, const char* trackname);
+void strip_tags(int handle_id);
 
 #endif
 

apps/playback.c

@@ -1485,6 +1485,10 @@ static void buffering_audio_callback(enum callback_event ev, int value)
             queue_send(&audio_queue, Q_AUDIO_FLUSH, 0);
             break;
 
+        case EVENT_HANDLE_FINISHED:
+            strip_tags(value);
+            break;
+
         default:
             break;
     }