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| ihope |
| Posted: Jul 17 2014, 08:46 AM |
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Newbie
Group: Members
Posts: 8
Member No.: 38155
Joined: 16-July 14
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Hello,
I have a question about cropping in virtual dub and aspect ratio of the final video.
I have a PAL Video (720*576) (SAR : 1,25 / PAR : 1,33 /DAR : 4/3 = 1,33) i want to convert in mp4 file.
If I crop this video (10 pixel bottom and top and 6 pixels left and right) how virtual dub will manage the aspect ratio?
I mean :
- The SAR of my video change : 700 * 564 (SAR : 1,24)
- The PAR of my video don't change (The pixel ratio in final is always 1,33)
=> So the DAR of my video change : DAR = PAR * SAR = 1,33 * 1,24 = 1,65
Does Virtual Dub will manage this correctly?
If VirtualDub don't correct this the risk is the player base the display on DAR and will show the video in 4/3 so this will be not correct !!!!!!!! |
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| malky |
| Posted: Jul 17 2014, 10:34 AM |
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Advanced Member
Group: Members
Posts: 290
Member No.: 22386
Joined: 6-November 07
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If the source is 720x576 and is cropped 10+10 from top/bottom and 6+6 left/right, surely it's now 708x556 - you say it's 700x564?
I think after cropping, if it's resized back to the original size and since mp4 uses square pixels, the new sar times the new par (1:1) the dar is back to 4:3. |
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| ihope |
| Posted: Jul 17 2014, 11:31 AM |
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Newbie
Group: Members
Posts: 8
Member No.: 38155
Joined: 16-July 14
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I would encode in H264.
=> I want delete 10 pixels left right and 6 top/bottom (mistake in my post).
I want just crop no resize (will affct the image ...)
I just want vdub crop the pixels and correct the DAR for the video display correctly by player in case DAR is used (or perhaps all players are using PAR?, i don't know) ... |
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| dloneranger |
| Posted: Jul 17 2014, 12:33 PM |
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Moderator
Group: Moderators
Posts: 2366
Member No.: 22158
Joined: 26-September 07
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dar and par are not set by virtualdub - any settings related to those are in the codecs's settings (or codecs and muxer if using external encoders)
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All FccHandlers Stuff inc. Installers for acm codecs AAC, AC3, LameMp3 |
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| ihope |
| Posted: Jul 17 2014, 02:43 PM |
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Newbie
Group: Members
Posts: 8
Member No.: 38155
Joined: 16-July 14
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Virtual dub don't send the aspect ratio to the codec? |
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| dloneranger |
| Posted: Jul 17 2014, 04:14 PM |
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Moderator
Group: Moderators
Posts: 2366
Member No.: 22158
Joined: 26-September 07
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There's no way to do it
Each codec (and/or muxer) has it's own way of setting it, and many can't at all
The same way that virtualdub doesn't send the 'quality' to an encoder - you have to set it in the encoder itself
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MultiAdjust JoinWav WavNormalize FFMPeg Input Plugin v1827 UnSharpMask
Windows7/8 Codec Chooser
All FccHandlers Stuff inc. Installers for acm codecs AAC, AC3, LameMp3 |
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