473,795 Members | 2,929 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

GZipStream compressed file is larger than source file

Hi,

I am using GZipStream to compress a simple text file approx 24MB in
size. I am finding that the destination "compressed " file is several
MB larger than the source file (31MB). The code is as follows:

Dim sourcefile As FileStream = File.OpenRead(i nFileName)
Dim destFile As FileStream = File.Open(outFi lename,
FileMode.Create , FileAccess.Writ e)

Dim compStream As New GZipStream(dest File,
CompressionMode .Compress)

Dim myByte As Integer = sourcefile.Read Byte()
While myByte <-1
compStream.Writ eByte(CType(myB yte, Byte))
myByte = sourcefile.Read Byte()
End While

Any ideas why the compressed file actually ends up larger than the
source?

Thanks,

Matt

Jun 23 '07 #1
1 2150
Note, I have experienced the same result when using other files types,
eg: pdf and doc. I even tried using a DeflateStream instead of
GzipStream, and still the destination files are consistently larger
than the source files...

Jun 23 '07 #2

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

0
2196
by: Craig Buchanan | last post by:
when i try to open a file that has been compressed with GZipStream (source from microsoft's 101 Samples for Visual Studio 2005), i get an "invalid archive" message from winzip, zipgenius and xp's compressed folder app. using DeflateStream resulted in the same error. am i missing something simple? thanks, Craig Buchanan
1
3307
by: KJ | last post by:
I am using the System.Compression.GZipStream class, and I noticed that in certain cases, the resultant compressed file is actually larger than the original. This is almost a constant when compressing already-compressed formats such as jpeg. Another less-consistent example of this behavior is found in the case of compressing TIFFs, wherein some files end up greatly compressed (the larger ones up to 93% compression ratio) and others end up...
1
3638
by: hakan.thornqvist | last post by:
I am using GZipStream for compression, and the size and contents of the compressed byte array differs from time to time, using the same source. byte uncompressed = Enc.GetBytes(xmlNode.OuterXml); byte compressed = compress(uncompressed); private byte compress(byte uncompressed) { MemoryStream ms = new MemoryStream();
1
10208
by: sedwick | last post by:
I'm using .NET 2.0.50727 in VS 2005 Pro, ENU Service Pack 1 (KB926601). I've been experimenting with the System.IO.Compression classes GZipStream and DeflateStream, and I found it interesting to note that they'll create different-sized compressed files depending on the procedure you use to take in the source file's data. With one, almost every file I feed them for compression ends up significantly bigger. That code is below, almost verbatim...
6
7455
by: =?Utf-8?B?QkRSaWNoYXJkc29u?= | last post by:
Hi, I have been using the new GZipStream classes, and have been experiencing problems when attemping to decompress files, which from experience, seem to be failing when the original file size exceeds something like 64 MB. For example, when I attempt to decompress a text file of size 1.18 MB to its original size of 106 MB, I receive the following error message: System.IO.IOException: Insufficient system resources exist to complete the
4
3459
by: Arnie | last post by:
Folks, The GZipStream class in .NET is throwing an exception during an OS unseal/power up (first boot experience). The .NET system is fully up as other apps seem to run fine.
2
2949
by: DR | last post by:
Why is its substantialy slower to load 50GB of gzipped file (20GB gzipped file) then loading 50GB unzipped data? im using System.IO.Compression.GZipStream and its not maxing out the cpu while loading the gzip data! Im using the default buffer of the stream that i open on the 20GB gzipped file and pass it into the GZipStream ctor. then System.IO.Compression.GZipStream takes an hour! when just loading 50GB file of data takes a few minutes!
5
2950
by: DR | last post by:
Why is its substantialy slower to load 50GB of gzipped file (20GB gzipped file) then loading 50GB unzipped data? im using System.IO.Compression.GZipStream and its not maxing out the cpu while loading the gzip data! Im using the default buffer of the stream that i open on the 20GB gzipped file and pass it into the GZipStream ctor. then System.IO.Compression.GZipStream takes an hour! when just loading 50GB file of data takes a few minutes!
11
7593
by: mach77 | last post by:
When using a GZipStream, is there any way to know how many compressed bytes were written? For example: // "buffer" is data from a text file // "offset" is 0 // "count" is 100 stream.Write(buffer, offset, count);
0
9673
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...
0
9522
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it. First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
1
10167
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
0
10003
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
0
9046
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own.... Now, this would greatly impact the work of software developers. The idea...
1
7544
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...
0
5440
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
0
5566
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
3
2922
bsmnconsultancy
by: bsmnconsultancy | last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.