cut video and save as direct stream copy

[supercain]

Hi,

i want to cut off parts of a video but without recoding. I use virtualdub for that but i have found it has a glitch because it doesnt cut exactly at the time frame i want, but always keeps some seconds before and no matter what i do i just cant cut that part off unless i recode. Is there any other program that can do that but do it right?

Thank you.

[filmboss80]

An issue discussed a thousand times. Obviously, you are using a compressed video with a long GOP structure. Unless you use smart rendering, you can only cut on I-frames, not P or B frames.

[supercain]

Well, sorry for not being around in any of the thousand times this issue was discussed... anyway, could you please tell me if smart render is possible in virtualdub?

[aedipuss]

what format? smart rendering is only possible on very few types of video with specific editors. mainly variants of mpeg-2, and DVavi.

[supercain]

The format is avi.

[manono]

Assuming it's XviD or DivX AVI then, yes, smart rendering is available for you. It'll reencode the rest of the GOP where you make the cut and direct stream the rest.

[Gavino]

could you please tell me if smart render is possible in virtualdub?

Strangely enough, this is described in the section on 'Smart rendering' in the VirtualDub help file.
Might be worth a read...

[supercain]

Nothing strange, i was using virtualdubmod, i assumed it had the same options. The video is avi but was made with mpeg (recorded with bandicam) and i already tried smart rendering but seems like it wont work. I get an error.

Isnt there any alternative for virtualdub? besides i dont want to render, i want direct stream copy because its much faster and there is no quality loss. There must be a way to cut off that part without recoding.

[jagabo]

VirtualDub's smart rendering will probably work if you install an old build of ffdshow and enable its VFW MPEG1 decoder and use its MPEG1 encoder. But recent builds of ffdshow have dropped most of the encoders so you'll have to search for an old build. I don't know exactly when the other encoders were dropped:

https://www.videohelp.com/tools/ffdshow/old-versions#download

One of the comments says rev3029 was the last build with all the encoders.

[supercain]

But smart rendering will take almost as much time as encoding, wont it?

[jagabo]

But smart rendering will take almost as much time as encoding, wont it?

No. Only cut GOPs are re-rendered.

[supercain]

Thanks. So i should get ffdshow rev3029, right?

[jagabo]

I just installed rev3029 and was able to smart trim the sample at bandicam.com. But I had to use AviFrate to change the frame rate of the source to 30000/1000.

[supercain]

I downloaded ffdshow but im unsure on what kind of installation to choose. I dont want my codecs or so to break or something. Should i choose the option that says use ffdshow to decode for all the codecs?

[jagabo]

For your purposes here you can disable all the audio and video codecs except "MPEG in AVI" in the VFW section.

[supercain]

I had already installed without checking any of the options. Should i reinstall it or can i set it up again even after having installed it?

[jagabo]

Just select Start -> All Programs -> ffdshow -> VFW Configuration. Go to the Decoder tab, select Decoder in the left pane, then scroll down to enable "MPEG in AVI" in the right pane. You can disable any other codecs that you want there. If they're giving you problems you can disable the DirectShow video and audio decoders if you want via Start -> All Programs -> ffdshow -> Video Decoder Configuration, and Start -> All Programs -> ffdshow -> Audio Decoder Configuration.

[supercain]

Hi,

i opened the program and went to the decoder tab, then decoder options but i cant find were to enable mpeg in avi.

where is it on the screen?

Thank you.

[jairovital]

where is it on the screen?

You are on "Decoder options". Click on "Codecs".

[supercain]

Thank you, i found the option. I selected libavcodec and then i opened my file in virtualdub, i cut off the part i dont need, selected smart rendering and the bandicam mpeg codec for the compression and i still get this error:

unable to initialize the output video codec. Check that the video codec is compatible with the output video frame size and that the settings are correct or try a different one.

By the way, im using the virtualdub i already had, the 1.9.11 version. I didnt choose to install it when i installed ffdshow since i already had virtualdub.

Thank you.

[jagabo]

unable to initialize the output video codec. Check that the video codec is compatible with the output video frame size and that the settings are correct or try a different one.

Did you select ffdshow as the encoder and set it to MPEG 1, one of the single pass modes?

[supercain]

Right now i have it like this



but i still get an error.. By the way, im choosing full processing mode. Should i choose something else?

Thank you.

[jagabo]

The sample clip I downloaded from bandicam.com had the frame rate set as 30000000 / 1000000. That was probably causing a numeric overflow in VirtualDub or ffdshow's frame rate calculations. I used AviFrate to change it to 30000 / 1000 to eliminate that problem.

What's the frame size of the video you're working with? Maybe ffdshow has different frame size limitations. Stick with mod 16 whenever possible.

Yes, you should be using Full Processing mode and Smart Rendering.

[supercain]

The video has a bitrate of 4519 and a frame rate of 30fps. Size is 1920x1080. I just want to cut off the undesired parts but keeping the same quality and not spend time in recoding it. Thank you for your help.

[supercain]

Hello? please help with this...

[Cauptain]

Tested some cuts on "Bandicam download sample" using VD Direct Stream Copy and no have any problems.



Claudio

[jairovital]

Hello? please help with this...

The same, here. I could smart render using Bandicam sample and ffdshow-MPEG1 encoder, with fine results.

Which is exactly your drama?

[supercain]

My problem is that i cant smart render. I have the same settings as in the picture of the post by jagabo. I get an error that says:

Unable to initialize the output video codec. Check that the video codec is compatible with the output video frame size and that the settings are correct or try a different one.

Sometimes i get also this one:

Cannot initialize smart rendering. The selected video codec is able to compress the video but cannot match the same compressed format.


i recorded my video using bandicam mpeg codec at 60% of quality. The video has a bitrate of 4519 and a frame rate of 30fps. Size is 1920x1080.Maybe you need to try out with my video to see better. Let me know if i should uploaded somewhere so you can see it.

Thanks.

[jairovital]

Unable to initialize the output video codec. Check that the video codec is compatible with the output video frame size and that the settings are correct or try a different one.

Like this?


It's because you are doing exactly what was said not to do. Pick another encoder, not BandMJPEG or other "decoder only" codec. Pick ffdshow (inside Vdub video compression window) and set it to MPEG1 as encoder (clicking Configure at the referred window).

As jagabo already said at #21.

[jairovital]

Let me know if i should uploaded somewhere so you can see it.

Upload some small part of your video to your own MyFiles area and put here the link. I'd have a look.