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  1. Member
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    Hi.
    I am using v1.9.11.

    It most often annoyingly does not observe frame accuracy at start (where I have cut a portion) and saves few earlier frames also.

    It never loses frames, just adds in some extra (only at start).

    For me this is a very annoying as it kills the purpose of accurate video editing and presentation.

    Is there any setting to tell it to keep frame accuracy to a specified number of frames?

    Thanks for help.
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  2. It's not possible for long GOP (group of picture) formats, using direct stream copy .

    The reason is because of the way long GOP compression works. Not every frame is encoded individually complete. Some rely on information from other frames . Only "I" frames are complete , so called "keyframes", and they define GOP boundaries. B and P frames rely on information from other frames. This is why you can only "cut on keyframes" or the boundaries between GOPS . The explanation for "adds frames" according your observation, is because it jumps to the nearest keyframe

    If you had an all I-frame format (ie. intraframe, not interframe) e.g. DV-AVI, uncomrpessed, cineform - then yes you can cut any frame with accuracy using direct stream copy

    Or if you use a "smart rendering" editor, you can cut anywhere with frame accuracy, because the few frames within that affected GOP are re-encoded e.g. videoredo, solveigmm video splitter, tmpgenc smart renderer

    vdub can smart render for xvid/divx
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  3. Originally Posted by poisondeathray View Post
    vdub can smart render for xvid/divx
    VirtualDub -> Video -> Smart Rendering. Configure Xvid/Divx with similar settings as the source video.
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  4. Member
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    Thanks. That was useful information. The concept is more clear now.

    Btw, the Avidemux you had earlier advised me can do much more accurate frame editing, altho it sometimes warns that cutting is not on I-frames. But it is much more obedient than Vdub
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    Don't blame Virtualdub. It was never designed primarily for the kind of editing you want to do with your specific type of encoded video.
    Last edited by sanlyn; 19th Mar 2014 at 07:24.
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  6. VirtualDub has keyframe buttons on the navigation bar for jumping between keyframes. They're not always where you want them to be but at least you should be able to see where the edits will actually happen. Although the keyframe buttons don't always seem to navigate accurately.... ie the video being displayed isn't necessarily correct.... even when editing Xvid encoded video.

    I'm sure it wasn't always this way..... is there a setting I'm missing? For example, the first screenshot is VirtualDub displaying frame number 1751. Then, after using the keyframe buttons to move back and forth a bit, VirtualDub displays a different frame as 1751. The video in question is an AVI, encoded by AutoGK.
    VirtualDubMod does the same. Maybe it's a decoding problem or the way the video was encoded? I haven't thought about it much until now. Maybe I should try a different version of ffdshow (I don't have Xvid installed so I assume ffdshow is decoding).

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  7. Originally Posted by hello_hello View Post
    For example, the first screenshot is VirtualDub displaying frame number 1751. Then, after using the keyframe buttons to move back and forth a bit, VirtualDub displays a different frame as 1751.
    If I remember correctly, it's a problem with open GOPs combined with unpacked b-frame sequences ("virutaldub hack" in Xvid).
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    I get the information about VDub. But sure, VDub has given me great services as far as avi files are concerned and I am keeping it. Its just that Avidemux can do so much more apparently.

    Thanks to everyone.
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  9. Originally Posted by seymoria View Post
    Its just that Avidemux can do so much more apparently.
    And it is much buggier once you go beyond simple AVI cuts.
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    Originally Posted by seymoria View Post
    I get the information about VDub. But sure, VDub has given me great services as far as avi files are concerned and I am keeping it. Its just that Avidemux can do so much more apparently.
    I doubt it, if you take the time to learn everything that Virtualdub can do. The Avidemux vs Virtualdub argument falls in the same category as PC vs Mac and Democrat vs Republican. I have Avidemux on my computer but I can't remember the last time that I even used it since I can do almost everything that I need to do with Virtualdub.
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  11. I'd agree, they fall in the same category. I have VirtualDub, VirtualDubMod and Avidemux installed, but aside from the occasional remux or video splitting, I rarely use any of them.
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  12. Originally Posted by seymoria View Post
    Hi.
    I am using v1.9.11.

    It most often annoyingly does not observe frame accuracy at start (where I have cut a portion) and saves few earlier frames also.

    It never loses frames, just adds in some extra (only at start).

    For me this is a very annoying as it kills the purpose of accurate video editing and presentation.

    Is there any setting to tell it to keep frame accuracy to a specified number of frames?
    If you want to be able to cut your video with guaranteed frame accuracy, convert the file into a high quality intraframe format like Canopus HQ or Cineform HD first (converters and codecs for both available for free online)
    That way you can cut with guaranteed frame accuracy in Virtualdub.....

    To convert to Canopus HQ you'll need to register an account with Grass Valley (free) and then download their AVCHD2HQ converter and HQ codec pack (you must be on Windows 7 or a Mac)
    Or, download the Cineform Codec from GoPro....

    If you insist on sticking with your long GOP original files, you will either have to cut with iframe accuracy only, or, as already suggested, use an editor that allows smart rendering.
    It's your choice.......
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  13. Member
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    Hi.
    Thanks all for the great pieces of advice as above. I see that for proper editing / frame accuracy, I have the following three options available :

    Option-1 : I should edit on keyframes (I-frames) only.
    This is the least complicated option and can be used with the freeware I already have (VirtualDub and Avidemux).
    My queries :
    (a) Can I use VirtualDub to properly identify I-frames so that I know where the cut will be made? As pointed out by hello_hello in above post, I-frame identification seems unreliable in VirtualDub as it shows two different I-frames with the same number at different instances.
    (b) For other than avi files which cannot be handled by VirtuallDub (mp4 files) I will have to use Avidemux. Please guide me how I can see the I-frames in Avidemux to see where the cuts will be made.

    Option-2 : I convert my files to a format with higher frame accuracy :
    I can download the freeware AVCHD2HQ converter and HQ codecs from Canopus HQ and then use my VirtualDub.
    My queries :
    (a) I would like to keep my files in a commonly used format like avi or mp4 as I have to watch them in my LaCie multimedia device on my TV and I doubt it can handle less common formats like Canopus.
    (b) I need something that is fast in its encoding algorithm as I have close to 4 TB of video files to edit. If paid software have faster encoding then I would prefer them.

    Option-3 : I use non freeware (paid) video editors that have smart rendering feature.
    These include videoredo, solveigmm, and tmpgenc. I can try out trial versions of these at first.
    My queries :
    (a) Is there a selection preference from these three?
    (b) My own criteria is something that can handle all major formats, wmv, avi and mp4. (I also have few mk4 and f4v).
    (c) The other criteria, again, is something that is fast in encoding algorithm as I have a large number of video files to edit.

    Thank you to all helpful members.
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  14. Originally Posted by seymoria View Post

    (a) Can I use VirtualDub to properly identify I-frames so that I know where the cut will be made? As pointed out by hello_hello in above post, I-frame identification seems unreliable in VirtualDub as it shows two different I-frames with the same number at different instances.
    Sometimes. It depends if the vdub hack is used, if b-frames are used in the video. Non IDR keyframes (there are IDR keyframes and non IDR keyframes) are not handled well in vdub or avidemux



    (b) For other than avi files which cannot be handled by VirtuallDub (mp4 files) I will have to use Avidemux. Please guide me how I can see the I-frames in Avidemux to see where the cuts will be made.
    It tells you in the status bar what type of frame, I, B, P. When you seek by the "<<"">>" buttons in the GUI, it should navigate by I frames. I gave these instructions already in your other thread. The problem is it doesn't distinguish between IDR keyframes and non IDR keyframes - that's why you can get "garbage" on the cuts, like green squares.

    You can think of IDR keyframes like "True" keyframes that completely limit a "traditional" GOP. Nothing in that GOP references outside of IDR delimiters. But non IDR keyframes are not true keyframes - there can be references outside - so that's why you get garbage on the cuts (incomplete data)

    Option-2 : I convert my files to a format with higher frame accuracy :
    I can download the freeware AVCHD2HQ converter and HQ codecs from Canopus HQ and then use my VirtualDub.
    My queries :
    (a) I would like to keep my files in a commonly used format like avi or mp4 as I have to watch them in my LaCie multimedia device on my TV and I doubt it can handle less common formats like Canopus.
    (b) I need something that is fast in its encoding algorithm as I have close to 4 TB of video files to edit. If paid software have faster encoding then I would prefer them.
    Note those suggestions mean re-encoding (the entire file) twice, not direct stream copy. If you were going to do that, I would use avisynth to make the cuts (you can index the files with frame accuracy), and re-encode once. Unless you use a lossless codec during the 1st re-encode, you will loss quality twice, not once

    Option-3 : I use non freeware (paid) video editors that have smart rendering feature.
    These include videoredo, solveigmm, and tmpgenc. I can try out trial versions of these at first.
    My queries :
    (a) Is there a selection preference from these three?
    (b) My own criteria is something that can handle all major formats, wmv, avi and mp4. (I also have few mk4 and f4v).
    (c) The other criteria, again, is something that is fast in encoding algorithm as I have a large number of video files to edit.
    Everyone has their preference. Some don't like the GUI or layout of one, but prefer another. Try out the free trials
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  15. Member
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    [QUOTE=poisondeathray;2300815]
    Originally Posted by seymoria View Post

    Option-3 : I use non freeware (paid) video editors that have smart rendering feature.
    These include videoredo, solveigmm, and tmpgenc. I can try out trial versions of these at first.
    My queries :
    (a) Is there a selection preference from these three?
    (b) My own criteria is something that can handle all major formats, wmv, avi and mp4. (I also have few mk4 and f4v).
    (c) The other criteria, again, is something that is fast in encoding algorithm as I have a large number of video files to edit.
    Everyone has their preference. Some don't like the GUI or layout of one, but prefer another. Try out the free trials
    Thanks for your detailed advice.

    I just installed VideoRedo trial and found that it cannot handle avi nor wmv files. So I am uninstalling it.

    Please guide me to the following :

    1) One that can handle the three major formats (mp4, avi and wmv; all these form the bulk of my video data). I also have few mkv and f4v.
    2) One that has faster encoding abilities. I was not impressed by VideoRedo.

    Kind Regards.
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  16. Only solveig. I dont think tmpgenc supports wmv. f4v might have to be remuxed to mp4, not sure if it's natively supported . Look at their webpages to see supported formats

    Encoding speed is limited by your computer . Smart rendering is pretty fast, only a few frames are re-encoded
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    Just downloaded the trial of solveigMM video splitter. Groping around to find my way through it. The GUI looks nice and simple though.

    Can you give some tips to do following simple actions :

    1) To mark start and end points for removing portions from a video.
    2) Option for Direct Stream Copy (without re-encoding).
    3) Saving the resulting file.

    I guess if I use Solveig itself for the editing, I do not need to use smart rendering since I am not using VirtualDub or Avidemux anymore.

    Also, I could not find how to use the Smart rendering feature in solveig. The menus or help doesn't mention it.

    Thank you for your help.
    Last edited by seymoria; 9th Feb 2014 at 13:32.
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  18. Originally Posted by seymoria View Post
    Just downloaded the trial of solveigMM video splitter. Groping around to find my way through it. The GUI looks nice and simple though.

    Can you give some tips to do following simple actions :

    1) To mark start and end points for removing portions from a video.
    2) Option for Direct Stream Copy (without re-encoding).
    3) Saving the resulting file.

    I guess if I use Solveig itself for the editing, I do not need to use smart rendering since I am not using VirtualDub or Avidemux anymore.

    Also, I could not find how to use the Smart rendering feature in solveig. The menus or help doesn't mention it.

    Thank you for your help.



    I'm pretty sure the basic instructions are in the manual. Go watch the video tutorials, it's easy to use

    To enable smart rendering, checkmark control=> frame accuracy (smart mode) . This is direct stream copy, except for those few frames around a cutsite

    Direct stream copy without smart rendering is functionally the same as avidemux, vdub. It's only GOP accurate. Uncheckmark frame accuracy if you want GOP accuracy, not frame accuracy (absolutely no re-encoding)

    Just slide the markers , Push M to add a new marker, or right click on the timeline and the options will be there
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  19. Member
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    Originally Posted by poisondeathray View Post
    To enable smart rendering, checkmark control=> frame accuracy (smart mode) . This is direct stream copy, except for those few frames around a cutsite

    Direct stream copy without smart rendering is functionally the same as avidemux, vdub. It's only GOP accurate. Uncheckmark frame accuracy if you want GOP accuracy, not frame accuracy (absolutely no re-encoding)

    Control>frame accuracy (smart mode). This option is greyed out (not available) for any file I tried. Why is this? I am very keen to use this option so please help me activate it.

    Thanks.
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  20. I don't know , maybe it's not activated in the demo version? (which would be stupid, what's the point of a demo then....)
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  21. Member
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    Thanks anyways. You have been a great help.
    I will try to ask any other member in a new thread in this forum.
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  22. Regardless of frame type, if you just want frame-accurate editing, try AviUtl.
    Completely free, but has a moderate learning curve
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  23. Member
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    VideoReDo TV Suite is mostly used for TV capture. MPEG2, MP4, TS, M2TS files. I believe it now supports mkv. IMO, it's the best program for that task and worth the $100 since none of the other programs advertised to edit TV capture do it as well as VideoReDo. It has a feature called Quick Stream Fix that can usually fix an MPEG2 file that is out of sync.

    For just about everything else, Virtualdub is my editor of choice. It can open just about any file with the help of input plugins and encode to just about any file type with the help of the external encoder feature using command line encoders. It can do Smart Render and you can do transitions like fade in and fade out using filters in Blend mode and using the curve editor. There are a few users on this site that can help with most issues concerning Virtualdub and there is an unofficial Virtualdub forum that has experts (including the creator of Virtualdub) to help with just about anything.

    http://forums.virtualdub.org/

    I would at least use the latest official build version 1.10.4 or one of the experimental versions like VirtualDub-1.10.5-test3

    Keep in mind that MP4 is meant to be the finished product and trying to do too many cuts at one time can crash even VideoReDo. Trying to seek back and forth can be pretty difficult for any program. One program that I found that works pretty well for making single cuts is Free Video Dub but it is very buggy if trying to make more than one cut at a time.
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