From c7acbfd90148c751fe2093308d14540eff9b0fe5 Mon Sep 17 00:00:00 2001
From: MaMazav <idanigra@hotmail.com>
Date: Wed, 17 Dec 2014 12:55:52 +0200
Subject: [PATCH] Support EPH and SOP markers.

---
 src/core/jpx.js | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/src/core/jpx.js b/src/core/jpx.js
index c7e1fd48c..c665689b9 100644
--- a/src/core/jpx.js
+++ b/src/core/jpx.js
@@ -324,12 +324,6 @@ var JpxImage = (function JpxImageClosure() {
                 cod.precinctsSizes = precinctsSizes;
               }
               var unsupported = [];
-              if (cod.sopMarkerUsed) {
-                unsupported.push('sopMarkerUsed');
-              }
-              if (cod.ephMarkerUsed) {
-                unsupported.push('ephMarkerUsed');
-              }
               if (cod.selectiveArithmeticCodingBypass) {
                 unsupported.push('selectiveArithmeticCodingBypass');
               }
@@ -816,6 +810,21 @@ var JpxImage = (function JpxImageClosure() {
       bufferSize -= count;
       return (buffer >>> bufferSize) & ((1 << count) - 1);
     }
+    function skipMarkerIfEqual(value) {
+      if (data[offset + position - 1] === 0xFF &&
+          data[offset + position] === value) {
+        skipBytes(1);
+        return true;
+      } else if (data[offset + position] === 0xFF &&
+                 data[offset + position + 1] === value) {
+        skipBytes(2);
+        return true;
+      }
+      return false;
+    }
+    function skipBytes(count) {
+      position += count;
+    }
     function alignToByte() {
       bufferSize = 0;
       if (skipNextBit) {
@@ -843,9 +852,15 @@ var JpxImage = (function JpxImageClosure() {
     }
     var tileIndex = context.currentTile.index;
     var tile = context.tiles[tileIndex];
+    var sopMarkerUsed = context.COD.sopMarkerUsed;
+    var ephMarkerUsed = context.COD.ephMarkerUsed;
     var packetsIterator = tile.packetsIterator;
     while (position < dataLength) {
       alignToByte();
+      if (sopMarkerUsed && skipMarkerIfEqual(0x91)) {
+        // Skip also marker segment length and packet sequence ID
+        skipBytes(4);
+      }
       if (!readBits(1)) {
         continue;
       }
@@ -928,6 +943,9 @@ var JpxImage = (function JpxImageClosure() {
         });
       }
       alignToByte();
+      if (ephMarkerUsed) {
+        skipMarkerIfEqual(0x92);
+      }
       while (queue.length > 0) {
         var packetItem = queue.shift();
         codeblock = packetItem.codeblock;