1 files changed, 75 insertions, 22 deletions

diff --git a/app/src/main/java/github/daneren2005/dsub/util/tags/OggFile.java b/app/src/main/java/github/daneren2005/dsub/util/tags/OggFile.java
index d0b31671..0383c68a 100644
--- a/app/src/main/java/github/daneren2005/dsub/util/tags/OggFile.java
+++ b/app/src/main/java/github/daneren2005/dsub/util/tags/OggFile.java
@@ -23,10 +23,11 @@ import java.io.RandomAccessFile;
 import java.util.HashMap;
 
 
-public class OggFile extends Common {
+public class OggFile extends Common implements PageInfo.PageParser {
 
-	private static final int OGG_PAGE_SIZE    = 27;  // Static size of an OGG Page
-	private static final int OGG_TYPE_COMMENT = 3;   // ID of 'VorbisComment's
+	private static final int OGG_PAGE_SIZE           = 27;  // Static size of an OGG Page
+	private static final int OGG_TYPE_IDENTIFICATION = 1;   // Identification header
+	private static final int OGG_TYPE_COMMENT        = 3;   // ID of 'VorbisComment's
 	
 	public OggFile() {
 	}
@@ -34,24 +35,46 @@ public class OggFile extends Common {
 	public HashMap getTags(RandomAccessFile s) throws IOException {
 		long offset = 0;
 		int  retry  = 64;
+		boolean need_tags = true;
+		boolean need_id = true;
+
 		HashMap tags = new HashMap();
+		HashMap identification = new HashMap();
 		
 		for( ; retry > 0 ; retry-- ) {
-			long res[] = parse_ogg_page(s, offset);
-			if(res[2] == OGG_TYPE_COMMENT) {
-				tags = parse_ogg_vorbis_comment(s, offset+res[0], res[1]);
+			PageInfo pi = parse_stream_page(s, offset);
+			if(pi.type == OGG_TYPE_IDENTIFICATION) {
+				identification = parse_ogg_vorbis_identification(s, offset+pi.header_len, pi.payload_len);
+				need_id = false;
+			} else if(pi.type == OGG_TYPE_COMMENT) {
+				tags = parse_ogg_vorbis_comment(s, offset+pi.header_len, pi.payload_len);
+				need_tags = false;
+			}
+			offset += pi.header_len + pi.payload_len;
+			if (need_tags == false && need_id == false) {
 				break;
 			}
-			offset += res[0] + res[1];
 		}
+
+		// Calculate duration in seconds
+		// Note that this calculation is WRONG: We would have to get the last
+		// packet to calculate the real length - but this is goot enough.
+		if (identification.containsKey("bitrate_nominal")) {
+			int br_nom = (Integer)identification.get("bitrate_nominal") / 8;
+			long file_length = s.length();
+			if (file_length > 0 && br_nom > 0) {
+				tags.put("duration", (int)(file_length/br_nom));
+			}
+		}
+
 		return tags;
 	}
 	
 	
-	/* Parses the ogg page at offset 'offset' and returns
-	** [header_size, payload_size, type]
-	*/
-	private long[] parse_ogg_page(RandomAccessFile s, long offset) throws IOException {
+	/**
+	 * Parses the ogg page at offset 'offset'
+	 */
+	public PageInfo parse_stream_page(RandomAccessFile s, long offset) throws IOException {
 		long[] result   = new long[3];               // [header_size, payload_size]
 		byte[] p_header = new byte[OGG_PAGE_SIZE];   // buffer for the page header 
 		byte[] scratch;
@@ -78,18 +101,18 @@ public class OggFile extends Common {
 				psize += b2u(scratch[i]); 
 			}
 		}
-		
-		// populate result array
-		result[0] = (s.getFilePointer() - offset);
-		result[1] = psize;
-		result[2] = -1;
-		
+
+		PageInfo pi    = new PageInfo();
+		pi.header_len  = (s.getFilePointer() - offset);
+		pi.payload_len = psize;
+		pi.type        = -1;
+
 		/* next byte is most likely the type -> pre-read */
 		if(psize >= 1 && s.read(p_header, 0, 1) == 1) {
-			result[2] = b2u(p_header[0]);
+			pi.type = b2u(p_header[0]);
 		}
-		
-		return result;
+
+		return pi;
 	}
 	
 	/* In 'vorbiscomment' field is prefixed with \3vorbis in OGG files
@@ -108,7 +131,37 @@ public class OggFile extends Common {
 		if( (new String(pfx, 0, pfx_len)).equals("\3vorbis") == false )
 			xdie("Damaged packet found!");
 		
-		return parse_vorbis_comment(s, offset+pfx_len, pl_len-pfx_len);
+		return parse_vorbis_comment(s, this, offset+pfx_len, pl_len-pfx_len);
 	}
-	
+
+	/*
+	 ** Returns a hashma with parsed vorbis identification header data
+	 **/
+	private HashMap parse_ogg_vorbis_identification(RandomAccessFile s, long offset, long pl_len) throws IOException {
+		/* Structure:
+		 * 7 bytes of \1vorbis
+		 * 4 bytes version
+		 * 1 byte channels
+		 * 4 bytes sampling rate
+		 * 4 bytes bitrate max
+		 * 4 bytes bitrate nominal
+		 * 4 bytes bitrate min
+		 **/
+		HashMap id_hash = new HashMap();
+		byte[] buff = new byte[28];
+
+		if(pl_len >= buff.length) {
+			s.seek(offset);
+			s.read(buff);
+			id_hash.put("version"         , b2le32(buff, 7));
+			id_hash.put("channels"        , b2u(buff[11]));
+			id_hash.put("sampling_rate"   , b2le32(buff, 12));
+			id_hash.put("bitrate_minimal" , b2le32(buff, 16));
+			id_hash.put("bitrate_nominal" , b2le32(buff, 20));
+			id_hash.put("bitrate_maximal" , b2le32(buff, 24));
+		}
+
+		return id_hash;
+	}
+
 };