Agent and yDec

Note that since the release of Agent v1.91 Forté Agent decodes yENC files directly and transparently. This addendum applies only to earlier versions of Agent, and by extension, to non-yEnc-enabled clients, such as Outlook Express. It is probable that this page will not be included in future revisions of the WarezFAQ, as the material is obsolete.

From the author’s site at:

http://www.yenc.org/ydec.htm

Modified for inclusion into the WarezFAQ.

(Also information gleaned from "El Smeggo’s" pdf on this subject.)

Usage of yDec

Download the yDec.zip (link on the site above) and extract the yDec.exe to any working directory. (Example: c:\ydec)
Use the function "File - Save as" in your newsreader to store a message which contains yEncoded binaries into the same directory.
It is helpful to use the .TXT file extension. (Example: msg1.txt - Directory: c:\ydec)
Open a command-line window (or DOS-Window)
Change to the temporary directory: (Example: cd c:\ydec)
Start the decoder: ydec msg1.txt
You can also store ten messages (msg1.txt, msg2.txt, ... msg10.txt) and use a wildcard as parameter: ydec *.txt
yDec writes the extracted files into the same directory.
Remove the stored message-text-files (Or keep them as backup).
Store the decoded binaries to another directory.

- or-

Create a simple batch file- named, for example, decode.bat - and include these lines:

ydec *.txt /a
del *.dec
end

Then run the batch file to decode whatever files you have in that folder that need decoding.

yDec can also be used with 'Drag and Drop' on Windows: You can simply click ONE stored message file and drag it to the yDec.exe. You can also create a shortcut for yDec on your desktop and drag a message file to that icon. The decoded binaries will still be stored at the location where the message file comes from! Dont try to drag multiple messages to yDec. It does not work.

Special cases

Corrupt messages (size error):
If yDec detects yEncoded attachments which are corrupt and have a wrong size then it still stores the attachment - but it extends the filename with the (size=#####) label.
NEVER repost or forward such corrupt binaries !
Corrupt messages (crc error):
If yDec detects yEncoded attachments which are corrupt and have a wrong CRC then it still stores the attachment - but it extends the filename with the (crc=abcdef) label.
NEVER repost or forward such corrupt binaries !

Multipart handling

If you receive a multipart message which is yEncoded then you have two choices:

You save each message (File - Save as) as an individual file to the temporary decoder directory (part1.txt, part2.txt, .. part69.txt)
Then you instruct yDec to decode all messages with a wildcard-command. Example: ydec part*.txt
You tell your newsreader to combine all the parts and store them as ONE big file to the decoder directory (bigfile.txt).
Then you instruct yDec to decode this big file. Example: ydec bigfile.txt

If the decoding can be completed without problems then the binary is written to the directory and an empty file with such a filename: orid-filename.ext(123456).dec are created. You can use the written file and remove the 'dec' file.

Missing parts

If yDec detects multipart messages then it instantly creates the FULL file - even if parts are missing. If (for example) the file: music.mp3 comes in 10 parts and the yDecoder finds one of them (not necessarily the first one) then it creates two temporary files:

music.mp3(1234567).tmp - and - music.mp3(1234567).dec

(The number is the size of the file). The first file is the temporary file which contains already the first part (and the rest is filled with 0xFF - decimal 255 - numbers). The second file is the information which bytes are still missed! As long as the extension of filename is (1234567).tmp as long the file is not yet complete! Perhaps some parts were corrupt - or simply not there.

If you are missing parts then you can get them later - and store them to your decoder directory. Then start yDec again on these new parts. The decoder will _automatically_ detect that additional parts are there - and insert them into the temporary file. As soon as the file gets complete the DEC file is empty and the TMP filename is changed to the real filename.

You should _never_ edit the DEC-file manually. This will simply cause problems.

Possible problem: If someone reposts a different binary under the identical name with the identical size then the decoder might fail!
If someone reposts the identical binary but in different part sizes then yDec is able to fill whatever is still necessary.

Duplicate filenames

If yDec is decoding a binary and its filename is already used - because there is still another file with that name - then it does NOT overwrite the old file. It issues a warning. Be sure to remove decoded files (and the message-files) after a job is done.

Debug display

If you want to see all the details of the running decoder then you can use the command line switch /a:

yDec msg1.txt /a	Decodes the message and shows all output in the DOS window
yDec *.txt /a	Decodes all the files with the extension *.txt
yDec *.txt /a \| more	Decodes everything and permits paging in the results
yDec *.txt /a > log.txt edit log.txt	Decodes everything and writes the progress to the log file. The EDIT command allows you to review the results.

Saving with Agent:

agent-ydec-1

To use yDec with Agent you must have Agent save the downloaded files/segments as Text. Multiple files and segments can be downloaded and saved into one text file if necessary. Once you have downloaded the files you wanted, highlight the ones you want to save as shown above. Note the two posting methods, in the first post there are three individual segments, due to the poster allowing the posting program to put the "yEnc" after the file name, and in the second post that was moved ahead of the file count, so that Agent combined the segments in the view. In either case you can simply save them without bothering to join segments in Agent.

Click on the “File” menu, and select the option “Save Messages As” option. agent-ydec-2 The browser will allow you to “Save In” – select the yDec folder and make sure you give the file a name ending with “.txt”. Check the "Save raw unformatted message” box, and the “No fields (body only)” box. When you click the “Save” button all the files you selected will be saved into this one big text file. yDec will both combine segments and separate posts into individual files when it runs.

The decoded zips/rars/mp3’s or whatever, will be in the folder with yDec. You must then move them elsewhere. agent-ydec-3 As you can see from the screenshot the two unrelated files were extracted from the "somestuff.txt" file and separated into individual files. The original "txt" file remains, and may be deleted manually, if the files had all their segments and decoded properly as these two did.