1 files changed, 215 insertions, 0 deletions

diff --git a/lib/rbcodec/metadata/ogg.c b/lib/rbcodec/metadata/ogg.c
new file mode 100644
index 0000000000..3a3cb29998
--- /dev/null
+++ b/lib/rbcodec/metadata/ogg.c
@@ -0,0 +1,215 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 Dave Chapman
+ *
+ * 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 <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <inttypes.h>
+
+#include "system.h"
+#include "metadata.h"
+#include "metadata_common.h"
+#include "metadata_parsers.h"
+#include "logf.h"
+
+/* A simple parser to read vital metadata from an Ogg Vorbis file. 
+ * Can also handle parsing Ogg Speex files for metadata. Returns
+ * false if metadata needed by the codec couldn't be read.
+ */
+bool get_ogg_metadata(int fd, struct mp3entry* id3)
+{
+    /* An Ogg File is split into pages, each starting with the string 
+     * "OggS". Each page has a timestamp (in PCM samples) referred to as
+     * the "granule position".
+     *
+     * An Ogg Vorbis has the following structure:
+     * 1) Identification header (containing samplerate, numchannels, etc)
+     * 2) Comment header - containing the Vorbis Comments
+     * 3) Setup header - containing codec setup information
+     * 4) Many audio packets...
+     *
+     * An Ogg Speex has the following structure:
+     * 1) Identification header (containing samplerate, numchannels, etc)
+     *    Described in this page: (http://www.speex.org/manual2/node7.html)
+     * 2) Comment header - containing the Vorbis Comments
+     * 3) Many audio packets.
+     */
+
+    /* Use the path name of the id3 structure as a temporary buffer. */
+    unsigned char* buf = (unsigned char *)id3->path;
+    long comment_size;
+    long remaining = 0;
+    long last_serial = 0;
+    long serial, r;
+    int segments, header_size;
+    int i;
+    bool eof = false;
+
+    /* 92 bytes is enough for both Vorbis and Speex headers */
+    if ((lseek(fd, 0, SEEK_SET) < 0) || (read(fd, buf, 92) < 92))
+    {
+        return false;
+    }
+    
+    /* All Ogg streams start with OggS */
+    if (memcmp(buf, "OggS", 4) != 0)
+    {
+        return false;
+    }
+
+    /* Check for format magic and then get metadata */
+    if (memcmp(&buf[29], "vorbis", 6) == 0)
+    {
+        id3->codectype = AFMT_OGG_VORBIS;
+        id3->frequency = get_long_le(&buf[40]);
+        id3->vbr = true;
+
+        /* Comments are in second Ogg page (byte 58 onwards for Vorbis) */
+        if (lseek(fd, 58, SEEK_SET) < 0)
+        {
+            return false;
+        }
+    }
+    else if (memcmp(&buf[28], "Speex   ", 8) == 0)
+    {
+        id3->codectype = AFMT_SPEEX;
+        id3->frequency = get_slong(&buf[64]);
+        id3->vbr = get_long_le(&buf[88]);
+
+        header_size = get_long_le(&buf[60]);
+
+        /* Comments are in second Ogg page (byte 108 onwards for Speex) */
+        if (lseek(fd, 28 + header_size, SEEK_SET) < 0)
+        {
+            return false;
+        }
+    }
+    else
+    {
+        /* Unsupported format, try to print the marker, catches Ogg/FLAC at least */
+        DEBUGF("Usupported format in Ogg stream: %16s\n", &buf[28]);
+        return false;
+    }
+
+    id3->filesize = filesize(fd);
+    
+    /* We need to ensure the serial number from this page is the same as the
+     * one from the last page (since we only support a single bitstream).
+     */
+    serial = get_long_le(&buf[14]);
+    comment_size = read_vorbis_tags(fd, id3, remaining);
+
+    /* We now need to search for the last page in the file - identified by 
+     * by ('O','g','g','S',0) and retrieve totalsamples.
+     */
+
+    /* A page is always < 64 kB */
+    if (lseek(fd, -(MIN(64 * 1024, id3->filesize)), SEEK_END) < 0)
+    {
+        return false;
+    }
+
+    remaining = 0;
+
+    while (!eof) 
+    {
+        r = read(fd, &buf[remaining], MAX_PATH - remaining);
+        
+        if (r <= 0) 
+        {
+            eof = true;
+        } 
+        else 
+        {
+            remaining += r;
+        }
+        
+        /* Inefficient (but simple) search */
+        i = 0;
+        
+        while (i < (remaining - 3)) 
+        {
+            if ((buf[i] == 'O') && (memcmp(&buf[i], "OggS", 4) == 0))
+            {
+                if (i < (remaining - 17)) 
+                {
+                    /* Note that this only reads the low 32 bits of a
+                     * 64 bit value.
+                     */
+                     id3->samples = get_long_le(&buf[i + 6]);
+                     last_serial = get_long_le(&buf[i + 14]);
+
+                    /* If this page is very small the beginning of the next
+                     * header could be in buffer. Jump near end of this header
+                     * and continue */
+                    i += 27;
+                } 
+                else 
+                {
+                    break;
+                }
+            } 
+            else 
+            {
+                i++;
+            }
+        }
+
+        if (i < remaining) 
+        {
+            /* Move the remaining bytes to start of buffer.
+             * Reuse var 'segments' as it is no longer needed */
+            segments = 0;
+            while (i < remaining)
+            {
+                buf[segments++] = buf[i++];
+            }
+            remaining = segments;
+        }
+        else
+        {
+            /* Discard the rest of the buffer */
+            remaining = 0;
+        }
+    }
+
+    /* This file has mutiple vorbis bitstreams (or is corrupt). */
+    /* FIXME we should display an error here. */
+    if (serial != last_serial)
+    {
+        logf("serialno mismatch");
+        logf("%ld", serial);
+        logf("%ld", last_serial);
+        return false;
+    }
+
+    id3->length = ((int64_t) id3->samples * 1000) / id3->frequency;
+    if (id3->length <= 0)
+    {
+        logf("ogg length invalid!");
+        return false;
+    }
+    
+    id3->bitrate = (((int64_t) id3->filesize - comment_size) * 8) / id3->length;
+    
+    return true;
+}
+