From 0073e3c6184aff0ade0fcf30d0a727a7a74d5c1a Mon Sep 17 00:00:00 2001
From: sbarman <sbarman@L3CWZ5T.(none)>
Date: Tue, 21 Jun 2011 13:34:35 -0700
Subject: [PATCH] initial impl of ASCII85 Decoding
---
pdf.js | 112 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 112 insertions(+)
diff --git a/pdf.js b/pdf.js
index fff135816..dfb47ea16 100644
--- a/pdf.js
+++ b/pdf.js
@@ -750,6 +750,116 @@ var DecryptStream = (function() {
return constructor;
})();
+var Ascii85Stream = (function() {
+ function constructor(str) {
+ this.str = str;
+ this.dict = str.dict;
+ this.eof = false;
+ this.pos = 0;
+ this.bufferLength = 0;
+ this.buffer = new Uint8Array(4);
+ }
+ constructor.prototype = {
+ getByte: function() {
+ if (this.pos >= this.bufferLength)
+ this.readBlock();
+ return this.buffer[this.pos++];
+ },
+ getBytes: function(n) {
+ var i, bytes;
+ bytes = new Uint8Array(n);
+ for (i = 0; i < n; ++i) {
+ if (this.pos >= this.bufferLength)
+ this.readBlock();
+ if (this.eof)
+ break;
+ bytes[i] = this.buffer[this.pos++];
+ }
+ return bytes;
+ },
+ getChar : function() {
+ return String.fromCharCode(this.getByte());
+ },
+ lookChar : function() {
+ if (this.pos >= this.bufferLength)
+ this.readRow();
+ return String.fromCharCode(this.currentRow[this.pos]);
+ },
+ skip : function(n) {
+ var i;
+ if (!n) {
+ n = 1;
+ }
+ while (n > this.bufferLength - this.pos) {
+ n -= this.bufferLength - this.pos;
+ this.readBlock();
+ if (this.bufferLength === 0) break;
+ }
+ this.pos += n;
+ },
+ readBlock: function() {
+ if (this.eof) {
+ this.bufferLength = 0;
+ this.buffer = [];
+ this.pos = 0;
+ return;
+ }
+
+ const tildaCode = "~".charCodeAt(0);
+ const zCode = "z".charCodeAt(0);
+ var str = this.str;
+
+ var c = str.getByte();
+ while (Lexer.isSpace(String.fromCharCode(c)))
+ c = str.getByte();
+ if (!c || c === tildaCode) {
+ this.eof = true;
+ return;
+ }
+
+ var buffer = this.buffer;
+ // special code for z
+ if (c == zCode) {
+ buffer[0] = 0;
+ buffer[1] = 0;
+ buffer[2] = 0;
+ buffer[3] = 0;
+ this.bufferLength = 4;
+ } else {
+ var input = new Uint8Array(5);
+ input[0] = c;
+ for (var i = 1; i < 5; ++i){
+ c = str.getByte();
+ while (Lexer.isSpace(String.fromCharCode(c)))
+ c = str.getByte();
+
+ input[i] = c;
+
+ if (!c || c == tildaCode)
+ break;
+ }
+ this.bufferLength = i - 1;
+ // partial ending;
+ if (i < 5) {
+ for (++i; i < 5; ++i)
+ input[i] = 0x21 + 84;
+ this.eof = true;
+ }
+ var t = 0;
+ for (var i = 0; i < 5; ++i)
+ t = t * 85 + (input[i] - 0x21);
+
+ for (var i = 3; i >= 0; --i){
+ buffer[i] = t & 0xFF;
+ t >>= 8;
+ }
+ }
+ }
+ };
+
+ return constructor;
+})();
+
var Name = (function() {
function constructor(name) {
this.name = name;
@@ -1354,6 +1464,8 @@ var Parser = (function() {
} else if (name == "DCTDecode") {
var bytes = stream.getBytes(length);
return new JpegStream(bytes, stream.dict);
+ } else if (name == "ASCII85Decode") {
+ return new Ascii85Stream(stream);
} else {
error("filter '" + name + "' not supported yet");
}