Difference between revisions of "ReNamer:Rules:Extension"

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(Created page with '== Extension Rule == [[Image:]]Sometimes a file has a missing or a wrong extension. This rule attaches the specified extension to the base file name. The parameters are as follo...')
 
(Extension Rule: Moved binary signatures into a separate section)
 
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{{Go|up=ReNamer:Rules|prev=ReNamer:Rules:Rearrange|next=ReNamer:Rules:Strip}}
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== Extension Rule ==
 
== Extension Rule ==
[[Image:]]Sometimes a file has a missing or a wrong extension. This rule attaches the specified extension to the base file name.
 
  
The parameters are as follows:
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<center>[[Image:ExtensionsRule.png]]</center>
  
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This rule allows you to attach a new extension. It is useful when the extension of a file is missing (or if the file has a wrong extension). There is an option to find the correct extension based on the file's structure.
  
{| class="prettytable"
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The parameters are as follows:
| <center>'''Parameter'''</center>
 
| <center>'''Details'''</center>
 
  
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{| class="wikitable"
 
|-
 
|-
| New extension
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! Parameter
| Simply adds the new extension to the file name.
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! Details
 
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|-
* ReNamer does ''not'' add a dot between the file name and the extension. So if the dot is missing in the file name, just enter a dot ''before'' the extension in this box. For example, instead of entering just '''pdf''', enter '''.pdf'''.
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| New extension  
 
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| New extension that has to be added to the filename.  
  
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|-
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| Append to the original filename
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| If this option is selected, the new extension will be placed after the old extension.
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If it is deselected (default option) the new extension will replace the old one.
  
 
|-
 
|-
| Append to the original filename
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| Detect using binary signature
| &nbsp;If this option is deselected, the new extension will replace the old extension. (This can be used if the file has a wrong extension, for example.)
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| Try to detect a correct file extension using built-in [[#Binary signatures|Binary signatures]] of commonly used files.
 
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|}
If the option is selected, the new extension is just added (This can be used when the file does not have any extension at all).
 
  
|-
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=== Binary signatures ===
| Detect using binary signature
 
| Sometimes the extension of a file is missing. At other times it is wrong (e.g. some downloaded files get the '''aspx '''extension, although they may be '''zip '''or '''pdf'''.)
 
  
One way to identify the file extension is by trial-and-error: Attach different extensions and try to open the file with its associated application. This is very tedious.
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Sometimes the extension of a file is missing. At other times it is simply wrong, e.g. some downloaded files get the '''aspx''' extension, although they may ''actually'' be '''zip '''or '''pdf''' files. One way to identify the file extension is by trial-and-error: Attach different extensions and try to open the file with its associated application. This is very tedious.  
  
A far more efficient way is to compare the file's ''digital signature ''with the signatures of known file types and identify the file's type. This is done internally within ReNamer, so you do not have to know what a “digital signature” means, or the actual value of the signature for the given file.
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A far more efficient way is to compare the file's ''digital signature'' with the signatures of known file types and identify the file's type. This is done internally within ReNamer, so you do not have to know what a ''digital signature'' means, or the actual value of the signature for the given file.  
  
Note that several extensions have overlapping digital signatures. Thus, once a digital signature is calculated for a file, ReNamer has to guess its extension. But compared to the trial-and-error method, we have to deal with far fewer extensions here.
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Note that each extension has a range of signatures, and these ranges overlap. This means a given file's signature may match with the signature of several different extensions. In such cases, ReNamer shows the New filename with all matching extensions. For example, "<tt>fileName.wma|wmv|asf</tt>". ReNamer also pops up an error window (because the combined extension is invalid). Just read the suggested extensions and then try them out one by one. This method is still better compared to making wild guesses, because ReNamer suggests only 2-3 extensions.
  
For better results, [http://www.den4b.com/forum/viewtopic.php?id=550 use ReNamer with TrID], a specialized utility for identifying the file's real extension.
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For more accurate results, use [[ReNamer:Scripts:TrID|ReNamer with TrID library]], a specialized utility for identifying the file's real extension. Be aware that even TrID often suggests multiple extensions, and you may still have to try them out.
  
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[[Category:ReNamer]]

Latest revision as of 16:08, 11 November 2015

Extension Rule

ExtensionsRule.png

This rule allows you to attach a new extension. It is useful when the extension of a file is missing (or if the file has a wrong extension). There is an option to find the correct extension based on the file's structure.

The parameters are as follows:

Parameter Details
New extension New extension that has to be added to the filename.
Append to the original filename If this option is selected, the new extension will be placed after the old extension.

If it is deselected (default option) the new extension will replace the old one.

Detect using binary signature Try to detect a correct file extension using built-in Binary signatures of commonly used files.

Binary signatures

Sometimes the extension of a file is missing. At other times it is simply wrong, e.g. some downloaded files get the aspx extension, although they may actually be zip or pdf files. One way to identify the file extension is by trial-and-error: Attach different extensions and try to open the file with its associated application. This is very tedious.

A far more efficient way is to compare the file's digital signature with the signatures of known file types and identify the file's type. This is done internally within ReNamer, so you do not have to know what a digital signature means, or the actual value of the signature for the given file.

Note that each extension has a range of signatures, and these ranges overlap. This means a given file's signature may match with the signature of several different extensions. In such cases, ReNamer shows the New filename with all matching extensions. For example, "fileName.wma|wmv|asf". ReNamer also pops up an error window (because the combined extension is invalid). Just read the suggested extensions and then try them out one by one. This method is still better compared to making wild guesses, because ReNamer suggests only 2-3 extensions.

For more accurate results, use ReNamer with TrID library, a specialized utility for identifying the file's real extension. Be aware that even TrID often suggests multiple extensions, and you may still have to try them out.