From 2f61f9c58a8fb3f345fc74b105c66908e360f436 Mon Sep 17 00:00:00 2001
From: snakemeat <snakemeat@51a99a44-fe44-0410-b1ba-c3e57ba2b86b>
Date: Tue, 16 Nov 2010 02:47:10 +0000
Subject: [PATCH] PS2 VGS - Add simple loop searching.  Not sure if I need to
 subtract 0x30 bytes header?

git-svn-id: https://vgmstream.svn.sourceforge.net/svnroot/vgmstream@880 51a99a44-fe44-0410-b1ba-c3e57ba2b86b
---
 src/meta/ps2_vgs.c | 73 +++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 63 insertions(+), 10 deletions(-)

diff --git a/src/meta/ps2_vgs.c b/src/meta/ps2_vgs.c
index 1a63cb04..8deadab7 100644
--- a/src/meta/ps2_vgs.c
+++ b/src/meta/ps2_vgs.c
@@ -5,8 +5,15 @@
 VGMSTREAM * init_vgmstream_ps2_vgs(STREAMFILE *streamFile) {
     VGMSTREAM * vgmstream = NULL;
     char filename[260];
-    off_t start_offset;
-    int loop_flag = 0;
+    
+	size_t fileLength;
+	off_t readOffset = 0;
+	off_t start_offset;
+	off_t loop_start_offset;
+	off_t loop_end_offset;
+
+	uint8_t	testBuffer[0x10];
+	int loop_flag = 0;
 	int channel_count;
 
     /* check extension, case insensitive */
@@ -14,28 +21,74 @@ VGMSTREAM * init_vgmstream_ps2_vgs(STREAMFILE *streamFile) {
     if (strcasecmp("vgs",filename_extension(filename))) goto fail;
 
     /* check header */
-
-	/* Look if there's more than 1 one file... */
     if (read_32bitBE(0x00,streamFile) != 0x56475300)
         goto fail;
 
-	loop_flag = 0;
+	// get file length
+	fileLength = get_streamfile_size(streamFile);	
+
+	// Find loop start
+	do {
+		readOffset += (off_t)read_streamfile(testBuffer, readOffset, 0x10, streamFile); 
+		
+		// Loop Start ...
+		if(testBuffer[0x01] == 0x06) 
+		{
+			loop_start_offset = readOffset - 0x10;	
+			break;
+		}
+
+	} while (streamFile->get_offset(streamFile)<((int32_t)fileLength));
+
+	// start at last line of file and move up
+	readOffset = (int32_t)fileLength - 0x10;
+	
+	// Find loop end
+	do {
+		readOffset -= (off_t)read_streamfile(testBuffer, readOffset, 0x10, streamFile); 
+		
+		// Loop End ...
+		if((testBuffer[0x01]==0x03) && (testBuffer[0x03]!=0x77)) 
+		{
+			loop_end_offset = readOffset +  0x20;
+			break;
+		}
+	} while (readOffset > 0);
+
+	// setup loops
+	if (loop_start_offset > 0)
+	{
+		loop_flag = 1;
+		
+		// if we have a start loop, use EOF if end loop is not found
+		if (loop_end_offset == 0)
+		{
+			loop_end_offset = (int32_t)fileLength - 0x10;
+		}
+	}
+	else
+	{
+		loop_flag = 0;
+	}
+
     channel_count = 2;
     
 	/* build the VGMSTREAM */
     vgmstream = allocate_vgmstream(channel_count,loop_flag);
     if (!vgmstream) goto fail;
 
-	/* fill in the vital statistics */
+	/* fill in the vital statistics */	
 	start_offset = 0x30;
 	vgmstream->channels = channel_count;
     vgmstream->sample_rate = read_32bitBE(0x10,streamFile);
     vgmstream->coding_type = coding_PSX;
 	vgmstream->num_samples = ((get_streamfile_size(streamFile)-0x30)/16/channel_count*28);
- //   if (loop_flag) {
- //       vgmstream->loop_start_sample = 0;
- //       vgmstream->loop_end_sample = (read_32bitLE(0x08,streamFile))/channel_count/32*28;
-	//}
+ 
+	if (loop_flag) 
+	{
+		vgmstream->loop_start_sample = loop_start_offset/16/channel_count*28;
+		vgmstream->loop_end_sample = loop_end_offset/16/channel_count*28;
+	}
 
     vgmstream->layout_type = layout_interleave;
     vgmstream->interleave_block_size = read_32bitBE(0x04,streamFile)*0x1000;