Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1
    Join Date
    Aug 2010
    Posts
    1,866
    News Credit
    119
    Mentioned
    0 Post(s)


    GUIDE: How to Repair an Archive with PAR2 Files

    Usenet is far superior in terms of storage and speed. You can usually download an 8GB file in 2 hours or less depending on your ISP's speed. Another added bonus is that for paid premium subscribers file retention is generally three years or more. This is great what with the unreliable nature of bittorrent and digital lockers.

    But with this superior platform there is the potential of files missing "segments". (Think of the RAR file being a wall and the segments being the bricks that make up the wall.) This is because, unlike digital lockers, usenet servers share all posts amongst each other; there is no centralize location. A missing segment can be a headache since it can prevent an archive from decompressing.

    That's where PAR2 files come in. If you download files from usenet they most likely will come with several PAR2 files. These files are basically an insurance: if a segment is missing these PAR2 files can patch the segment and allow the archive to decompress properly.

    The process is pretty painless and only requires one program. Uploaders use this program to create the PAR2 files, and end users can use it to repair broken files. Here is how you can repair a broken archive downloaded from usenet.

    Requirements:
    MultiPar
    Archive with PAR2 files (labeled like ".vol000+004.par2", ".vol004+007", etc.)


    1. Start MultiPar. In the bottom left corner of the program is a button labeled Open. Click this and navigate to where you downloaded the files. Choose the .PAR2 file and click Open.
    2. MultiPar will now verify your PAR2 files, and then it will scan your RAR files. Once it's done it should tell you how many more blocks are needed. Fear not! If you have all the PAR2 then the Repair button should be clickable. Click it.
    3. QuickPar will now repair the archive and you should be good to go!


    NOTE: Some usenet downloaders (SABnzbd, etc.) automatically have repair options enabled. The problem is that these programs delete the repair PAR2 files even if they unsuccessfully repair the files. It is best to disable automatic repairs using these program and do it manually.
    Last edited by Q2; 08-22-2014 at 12:14 PM.

  2. #2
    Join Date
    Mar 2011
    Location
    United States of America
    Posts
    2,361
    News Credit
    0
    Mentioned
    28 Post(s)


    I just encountered a scenario with one of l8wrtr's edits where the repair function didn't accomplish anything. I am still very new at this, so the following hypothesis as to why might be wrong, but I am guessing it had to do with the fact that the RAR file segments were split into 200MB segments instead of 50 MB segments, per the details in your uploading to usenet guide.
    Projects Completed:
    Matrix Revolutions - The Epic Edition
    The Two Towers Rebuilt

    Projects truly In the Works:
    Star Trek (2009): Gem Edition

    Projects kinda sorta conceptually In The Works:
    Riddick: The Chronicles
    Star Wars: Return Of The Jedi
    Who Watches The Watchmen

  3. #3
    Join Date
    Dec 2008
    Location
    Somewhere But Not Here
    Posts
    4,673
    News Credit
    50
    Mentioned
    76 Post(s)


    Quote Originally Posted by geminigod View Post
    I just encountered a scenario with one of l8wrtr's edits where the repair function didn't accomplish anything. I am still very new at this, so the following hypothesis as to why might be wrong, but I am guessing it had to do with the fact that the RAR file segments were split into 200MB segments instead of 50 MB segments, per the details in your uploading to usenet guide.
    I do 200MB segments too when working with larger files. I think I said 50MB for 1000MB or less. Don't remember though.
    Completed Fanedits: See IFDB Page

  4. #4
    Join Date
    Jan 2011
    Location
    In the ghetto
    Posts
    11,210
    News Credit
    61
    Mentioned
    146 Post(s)


    I personally found that when using 200MB files to upload to Usenet I was getting more corrupted files. It may be because of my internet connection, but when I do 50MB I'll get maybe only 1 corrupted file at most. It still sucks to have that corrupted file but 1 part missing is better than 19 parts missing.
    Go then, there are other worlds than these.

  5. #5
    Join Date
    Dec 2008
    Location
    Somewhere But Not Here
    Posts
    4,673
    News Credit
    50
    Mentioned
    76 Post(s)


    I've never had that many parts missing. I think at most was two segments in two separate RAR files. I just re-uploaded those missing segments and all was good.
    Completed Fanedits: See IFDB Page

  6. #6
    Join Date
    Mar 2011
    Location
    United States of America
    Posts
    2,361
    News Credit
    0
    Mentioned
    28 Post(s)


    I think this may shed some light on the matter.

    http://www.binaries4all.com/optimizing/

    I am still not 100% certain that size of rar file doesn't matter. It seems logical that larger file sizes might have increased chance of data loss or corruption as they bounce around servers. The largest example used on that link is ~50MB (ideally 49.92MB).

    I'll try to recap the math here:
    yenc line (which is the actual binary coding language) = 128 characters.
    max allowed lines per segment = 5000 lines
    So 1 segment = 128*5000 = 640,000 bytes

    RAR files should be a multiple of this. So theoretically we could do a RAR file that is 310 segments * 640,000 bytes = 198,400,000 bytes.

    Then in multiPAR we set the PAR2 block size to equal the segment size of 640,000 bytes so that repair is optimized.
    Last edited by geminigod; 08-03-2012 at 12:15 AM.
    Projects Completed:
    Matrix Revolutions - The Epic Edition
    The Two Towers Rebuilt

    Projects truly In the Works:
    Star Trek (2009): Gem Edition

    Projects kinda sorta conceptually In The Works:
    Riddick: The Chronicles
    Star Wars: Return Of The Jedi
    Who Watches The Watchmen

  7. #7
    Join Date
    Mar 2011
    Location
    United States of America
    Posts
    2,361
    News Credit
    0
    Mentioned
    28 Post(s)


    1 out of 1 members like this post.
    Case and point, Q2, I just finished downloading your BD of episode 2 using SABnzbd. Repair took forever. Ultimately it failed against SFV verification saying it was 2 repair blocks short. Your file sizes were 204,800 KB. Repair took forever. 10 PAR2 repair files were created.

    20 gigs and $2 later, I'm not sure what to do now as far as whether this download is salvageable or not. Same issue I had with L8wrtr's Episode 1 BD.

    EDIT: Success. When all was said and done after my newsreader failed to repair, I clicked on the small par2 index file (as multiple guides have indicated) and multipar app examined the download. It stated that 2 slices/articles/segments or whatever the fuck you want to call them were missing. It also said that the large par2 repair files were "useless". Clicking the repair button did nothing. So I exited multipar, read this: http://www.slyck.com/Newsgroups_Guide_PAR_PAR2_Files, and then clicked on one of the large par2 repair files that my newsreader had put together. That opened multipar back up and suddenly it was magically fixed. {Head scratch... shrug... WTF}
    Last edited by geminigod; 08-03-2012 at 01:05 AM.
    Projects Completed:
    Matrix Revolutions - The Epic Edition
    The Two Towers Rebuilt

    Projects truly In the Works:
    Star Trek (2009): Gem Edition

    Projects kinda sorta conceptually In The Works:
    Riddick: The Chronicles
    Star Wars: Return Of The Jedi
    Who Watches The Watchmen

  8. #8
    Join Date
    Dec 2008
    Location
    Somewhere But Not Here
    Posts
    4,673
    News Credit
    50
    Mentioned
    76 Post(s)


    Good to know Gemini. Thanks for sharing!
    Completed Fanedits: See IFDB Page

  9. #9
    Join Date
    Dec 2011
    Location
    Massachusetts, USA
    Posts
    163
    News Credit
    0
    Mentioned
    2 Post(s)


    I'm having an issue that could hopefully be helped. The CRC check fails in SABnzbd and I also get the following errors when using WinRAR.

    ! BD25.part023.rar: Packed data CRC failed in \BDMV\STREAM\00005.m2ts. The volume is corrupt
    ! BD25.part102.rar: CRC failed in \BDMV\STREAM\00005.m2ts. The file is corrupt

    I've tried using QuickPAR, but it says the files are not in need of repair. Same with MultiPAR. I could use some help. Thanks.

  10. #10
    Join Date
    Oct 2011
    Posts
    568
    News Credit
    0
    Mentioned
    1 Post(s)


    Quote Originally Posted by Dethryl View Post
    I'm having an issue that could hopefully be helped. The CRC check fails in SABnzbd and I also get the following errors when using WinRAR.

    ! BD25.part023.rar: Packed data CRC failed in \BDMV\STREAM\00005.m2ts. The volume is corrupt
    ! BD25.part102.rar: CRC failed in \BDMV\STREAM\00005.m2ts. The file is corrupt

    I've tried using QuickPAR, but it says the files are not in need of repair. Same with MultiPAR. I could use some help. Thanks.
    That sounds like there was corruption before the faneditor uploaded the file. I would contact them directly and see if they have a fix.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Fanedit.org is not affiliated with Fanedit.info

Visitors to Fanedit.org are advised that all fanedits contained within the pages of the websites are believed to be fanedits and/or preservation projects of films from personal collections which fall under the Copyright Act of 1976, 17 U.S.C. § 107, which states: Notwithstanding the provisions of sections 106 and 106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include— 1. the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; 2. the nature of the copyrighted work; 3. the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and 4. the effect of the use upon the potential market for or value of the copyrighted work. Since fanedits contained here are mainly created out of criticisms, research, and are completely nonprofit, we here at Fanedit.org believe that they fall under the requirements of the Copyright Act of 1976, 17 U.S.C. § 107. However, no claims, promises or guarantees about the accuracy, completeness, or adequacy of the information are made. Visitors are encouraged to review the official version of all documents upon which they plan to download as well as to make completely sure they own a legitimate, original copy of anything they may wish to download. The safest course is always to get permission from the copyright owner before using copyrighted material. Fanedit.org cannot give this permission. Legal Disclaimer Regarding Links to Other Sites - Some of the linked sites are not under the control of Fanedit.org. Therefore, Fanedit.org makes no representations concerning their content, and are not responsible for their content. That Fanedit.org has provided a link to a site is not an endorsement, or an indication of affiliation with the owners or publishers of any fanedits and all related materials. There are risks in using any information, services or fanedits found on the Internet via any outside links; and Fanedit.org cautions you to make sure that you completely understand these risks before retrieving, using, relying upon, or downloading anything via the Internet. Legal Disclaimer Regarding Members, Fanedits and Links. Fanedit.org reserves the right to refuse services at any time. Notification that Information Provided by You is Public Information Any information provided by you to Fanedit.org, including but not limited to feedback, questions, comments, suggestions, download links, etc., etc., are considered non-confidential since it is a public website; moreover, such information is a public record subject to public inspection pursuant to law. Fanedit.org has no obligation of any kind with respect to such information and cannot be held responsible for the decisions nor the actions of any individuals of the entire Internet community at large. By downloading any fanedit, the downloader assumes all responsibilities thereof as well as all the consequences that may incur. CONSIDER YOURSELF WARNED!