From 21888f54d77d5a039f68cbe6e7746a11b4b26832 Mon Sep 17 00:00:00 2001
From: nareix <hi.nareix@gmail.com>
Date: Fri, 18 Mar 2016 20:11:54 +0800
Subject: [PATCH] add track.go

---
 demuxer.go | 34 ++++++++++++++++++++++++++++++++++
 track.go   |  7 +++++++
 2 files changed, 41 insertions(+)

diff --git a/demuxer.go b/demuxer.go
index c1d0984..bf4b5c6 100644
--- a/demuxer.go
+++ b/demuxer.go
@@ -109,6 +109,40 @@ func (self *Track) setSampleIndex(index int) (err error) {
 		return
 	}
 
+	start = 0
+	found = false
+	self.ptsEntryIndex = 0
+	for self.ptsEntryIndex < len(self.sample.TimeToSample.Entries) {
+		n := self.sample.TimeToSample.Entries[self.ptsEntryIndex].Count
+		if index >= start && index < start+n {
+			self.sampleIndexInPtsEntry = index-start
+			break
+		}
+		start += n
+		self.ptsEntryIndex++
+	}
+	if !found {
+		err = io.EOF
+		return
+	}
+
+	start = 0
+	found = false
+	self.dtsEntryIndex = 0
+	for self.dtsEntryIndex < len(self.sample.CompositionOffset.Entries) {
+		n := self.sample.CompositionOffset.Entries[self.dtsEntryIndex].Count
+		if index >= start && index < start+n {
+			self.sampleIndexInDtsEntry = index-start
+			break
+		}
+		start += n
+		self.dtsEntryIndex++
+	}
+	if !found {
+		err = io.EOF
+		return
+	}
+
 	self.sampleIndex = index
 	return
 }
diff --git a/track.go b/track.go
index e4bb9b9..b68e0e1 100644
--- a/track.go
+++ b/track.go
@@ -20,6 +20,13 @@ type Track struct {
 
 	sample *atom.SampleTable
 	sampleIndex int
+
+	ptsEntryIndex int
+	sampleIndexInPtsEntry int
+
+	dtsEntryIndex int
+	sampleIndexInDtsEntry int
+
 	chunkGroupIndex int
 	chunkIndex int
 	sampleIndexInChunk int