From ef7d4785e0ce824b06f4e098292c94ca2ea641a6 Mon Sep 17 00:00:00 2001
From: wforums <webmaster@wforums.net>
Date: Sun, 22 Jun 2014 09:39:17 +0200
Subject: [PATCH 1/2] Fix for mp4

Fixed the wrong subtitles on the given iphone sample by splitting up the
sample into multiple atoms (if present) instead of just one. Tested
change with a second (already working) sample, nothing broke there.
---
 src/gpacmp4/mp4.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/gpacmp4/mp4.c b/src/gpacmp4/mp4.c
index 8fade90a..fcb48fe5 100644
--- a/src/gpacmp4/mp4.c
+++ b/src/gpacmp4/mp4.c
@@ -292,12 +292,35 @@ int processmp4 (char *file)
 					pts_set=1;
 				set_fts();
 
+				// Change by Willem
+
 				// Apparently the first 4 bytes are the sample length, and then comes 'cdat', and then the data itself
-				if (sample->dataLength>8 && strncmp (sample->data+4, "cdat", 4)==0)
+				/*if (sample->dataLength>8 && strncmp (sample->data+4, "cdat", 4)==0)
 				{
-					// dump (256,( unsigned char *) sample->data+8,sample->dataLength-8,0, 1);				
+					//dump (256,( unsigned char *) sample->data+8,sample->dataLength-8,0, 1);	
 					process608((const unsigned char *)sample->data + 8, sample->dataLength - 8, &context_cc608_field_1);
+				}*/
+				
+				// Based on https://developer.apple.com/library/prerelease/mac/documentation/QuickTime/QTFF/QTFFChap3/qtff3.html#//apple_ref/doc/uid/TP40000939-CH205-SW87
+				// An atom consists of the Atom size, Atom Type and the data.
+				// First 4 bytes are length in bytes of this atom
+				// byte 5-8 are the atom type. Should be either cdat or cdt2
+				// byte 9-x are actual data.
+				// This means a sample can contain multiple atoms!
+				if (sample->dataLength > 8 && strncmp(sample->data + 4, "cdat", 4) == 0){ // The format of the closed captioning sample data is a sequence of one or more atoms, one of which must be a 'cdat' atom.
+					int atomStart = 0;
+					// process Atom by Atom
+					while (atomStart < sample->dataLength){
+						unsigned int atomLength = (unsigned char)sample->data[atomStart] << 24 | (unsigned char)sample->data[atomStart + 1] << 16 | (unsigned char)sample->data[atomStart + 2] << 8 | (unsigned char)sample->data[atomStart + 3];
+						if (atomLength > 8 && (strncmp(sample->data + atomStart + 4, "cdat", 4) == 0 || strncmp(sample->data + atomStart + 4, "cdt2", 4) == 0)){
+							dump(256, (unsigned char *)sample->data +atomStart+ 8, atomLength - 8, 0, 1);
+							process608((const unsigned char *)sample->data + atomStart + 8, atomLength - 8, &context_cc608_field_1);
+						}
+						atomStart += atomLength;
+					}
 				}
+
+				// End of change
 				int progress = (int) ((k*100) / num_samples);
 				if (last_reported_progress != progress)
 				{

From 86ef6d521e09fb862bb1c1f80d2045485d1d74bc Mon Sep 17 00:00:00 2001
From: wforums <webmaster@wforums.net>
Date: Sun, 22 Jun 2014 11:57:06 +0200
Subject: [PATCH 2/2] Added a description of fix in changes.txt

---
 docs/CHANGES.TXT | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/docs/CHANGES.TXT b/docs/CHANGES.TXT
index b3167f3c..7172a8cf 100644
--- a/docs/CHANGES.TXT
+++ b/docs/CHANGES.TXT
@@ -7,6 +7,8 @@ version of CCExtractor.
 
 - Added a huge dictionary submitted by Matt Stockard.
 - Added DVB subtitles decoder, spupng in output
+- Added support for cdt2 media atoms in QT video files. Now multiple atoms in
+ a single sample sequence are supported.
 
 0.69
 ----