Solved

Any little change in the video file results in change of file size, correct?

Posted on 2013-01-29
9
481 Views
Last Modified: 2013-01-30
Dear experts

I should create a WinForm C# application which works with video files. The files are keep both in FTP server and locally on HDDs. When a user want to watch a video file first I check on HDD and if the file is missing, or it is different then I should start download. The question is – how to determine if a video file is different than the others /both files are with same names/? For now I plan to use their size FileBytes, is this enough for 99.99 of the cases?

 The video files will be played in TV, so there will be a case where the movie is created with for example Adobe Premiere, then it is modified very little and save again – is this mean that the file’s result size (bytes)  will be different than the previous file?
0
Comment
Question by:dvplayltd
  • 5
  • 3
9 Comments
 
LVL 5

Expert Comment

by:msallam
ID: 38830467
The MD5 hash is unique for all file types.

You can try if it is feasible in your case.
0
 

Author Comment

by:dvplayltd
ID: 38830550
Well, this is not my question, my question is with video edition softwares like Adobe Premiere and exc. - are thay always make video files with different size, but as you start to talk about this – fine.

 I guess I can easy make a MD5 has to my local file, but is there a command to FTP server to create MD5 hash and to return it to me ? I need to work with all FTP servers both under Windows and Linyx .
0
 
LVL 16

Accepted Solution

by:
AlexPace earned 500 total points
ID: 38830690
Some FTP clients and servers support integrity checking protocol-level commands like XMD5, XCRC and/or XSHA1.  These are not supported by FileZilla but others like Robo-FTP and Voyager support them.

If all the supported file types are known and you also control the server then perhaps you could use information in the file header bytes to avoid generating a fingerprint of the whole thing on both ends.
0
 

Author Comment

by:dvplayltd
ID: 38831853
We are going in other direction, let remain the question:

  When 2 video files are different with for example one letter fixed in a title in the video file /made with video editor software like Adobe Premier/ - this will result in file with different size, or it is possible both files (old and new one) to get exactly same size in bytes on HDD???
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 
LVL 16

Expert Comment

by:AlexPace
ID: 38832053
Actual file size (not size on disk) is probably good enough for 99% ... it would be rare to come up with the exact same size unless there is a concern of deliberate tampering.  If there is no money involved then what is the motivation to tamper?  A prank perhaps...  If there is money involved then use a hash.
0
 

Author Comment

by:dvplayltd
ID: 38832280
hash will require too much power from CPU, and this will be operation done all the time.

A money are not involved and nobady will have finance interest to make special dublicate, but it is quite possible the TV channel to make a new version of video file which is different with one letter shown as title on the movie, and then this change should be detected, or the customer wil watch the old version from its HDD, while there is a new version on FTP.

In short, the question is for video movies editor ...
0
 

Author Closing Comment

by:dvplayltd
ID: 38834387
10x. One friend workng in video area tell me that for my case the new and old file will be with equal size. So I should check local and FTP file with XMD5 ... Could you please recomended me most populiar protocol suported from public FTP servers? My ask is for big name in FTP servers , like IIS7 , Apache under Linyx and so on - i'm using shared FTP server hosted in data center, not some home made FTP .
0
 
LVL 16

Expert Comment

by:AlexPace
ID: 38835705
FTP directory listings usually show the last modified time.  After downloading a copy of the file you could use your app to programmatically change the last modified date on the local copy.  It would be unlikley that the file size and date would both remain the same unless someone was intentially messing with you. Integrity checking is hte only way to prevent that but even then I suspect a XCRC may run a faster on the server's CPU than an XMD5.
0
 

Author Comment

by:dvplayltd
ID: 38838208
Your last idea for last modify date is good, but I already implement XMD5 check. Because the video files will be played with playout software I  need not only to check for a new video file version, but also to make 100 % sure that there no error on FTP download/upload and this could be ensure only of XMD5 check.

Thanks for your answer and time!
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I have a Synology DS212+ NAS.  These are not only great for backup and normal NAS stuff, but also for delivering media throughout your home or LAN via DLNA.  I copied my whole audio collection from iTunes over to the box, but couldn't figure out how…
Tired of waiting for your show or movie to load?  Are buffering issues a constant problem with your internet connection?  Check this article out to see if these simple adjustments are the solution for you.
Viewers will get an overview of how to make and use Drum Racks in Ableton Live. Load new Drum Rack into empty MIDI track: Fill rack with audio samples: Re-arrange sample slots as necessary: Adjust parameters of each slot to tailor each sound a…
Viewers will learn how to create and use Simpler instruments in Ableton Live. Load new Simpler into an empty MIDI track: Select a sample and drop it into sample window in Simpler: If sample is not pitched at C3, adjust tuning with Transpose para…

910 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

21 Experts available now in Live!

Get 1:1 Help Now