Use Virtual Dub to edit / cut by frame numerically

[jagabo]

Can I make the edit then go to compression and select that as part of one operation?

Yes.

Which is a good default compression selection to make? I know we mentioned 640x480 (down from the 1280 x 720 original.)

What is your intention for the output file? Do you plan to do perform more filtering in some other program later? Then use a lossless codec. If this is your final edit use a high compression codec like x264vfw or Xvid.

I simply don't know how to do the setup yet, though I was able to go to a key frame, make the snip and do that much.

If you're going to recompress the video you don't need to cut on key frames. You can cut anywhere you want. Only when you are using Direct Stream Copy mode that you need to cut on key frames.

Also I know Hello Hello mentioned making two passes manually. Is that a relevant operation here?

It is if you are using a 2-pass encoding mode.

Elsewhere I'm getting some forum advice about simply taking my work disk off the network and removing network folders thereby getting what should be plenty of room.

Just save the video wherever you have room. VirtualDub lets you save it wherever you want.

[loninappleton]

I haven't got my space requirements fixed yet for the work disk but I'll do more today
and inspect what is available for compression.

I will build my self a guide from these answers.

[loninappleton]

In full processing mode if you don't select a compression codec (Video -> Compression...) you get uncompressed video in your output file.

For a practice I am running another Save with one of the standard available compression options which is ffdshow. I made the snip again and working from an original version of the content.

I may have a long way to go with this. The Quality remains the default at 85.
The dialog says 'Must be a multiple of 2.'

Yet I see no dialog to set a numeric value. We discussed using 640x480 (from memory.)
How is the x2 value given to FFdshow?

As to h264, yes I can download something like that but how is it installed? In the plugins or is it
an auto installer and Vdub will show it in the Compression menu?

I will at least use the reference above for h264 and begin the process of getting it.

Disk space remains a question.

[jagabo]

ffdshow. I made the snip again and working from an original version of the content.

I may have a long way to go with this. The Quality remains the default at 85.
The dialog says 'Must be a multiple of 2.'

Yet I see no dialog to set a numeric value. We discussed using 640x480 (from memory.)
How is the x2 value given to FFdshow?

That means both the frame width and height must be an integer multiple of 2. Both 640 and 480 are integer multiples of 2 (320 *2, and 240 * 2).

As to h264, yes I can download something like that but how is it installed? In the plugins or is it
an auto installer and Vdub will show it in the Compression menu?

All codecs that VirtualDub can use are system installed VFW codecs. They do not go in VirtualDub's folders. x264vfw comes with its own installer.

Disk space remains a question.

Disk space probably won't be an issue if you use compression. If you use a bitrate lower than that of your source the video will be smaller than the source, not a gigantic hundreds of GB file.

[loninappleton]

I have seen the screen shot above of the h264 codec. Looks like that is a separate program
in which to put the values. I have look back at the ffdshow screen shot as well

With just the defaults mentioned above, the encode did complete-- but at 16 Gb. It looks pretty sharp yet.
I will use Media Info to look at the details.

Other techniques are needed to get it down to the desired 1.67 or Gb.

Are there options to specify the size and the program calculates what needs to be done?

Regardless I'm glad I got something to look at. I would add other ornaments to the tree with a
volume increase previously described for example. But at some point I want to run my audio leveling tools.

I'll complete the install of the h264 program.

[jagabo]

I have seen the screen shot above of the h264 codec. Looks like that is a separate program
in which to put the values.

If you're talking about the dialog in post #83 of this thread, that's x264vfw's configuration dialog. If you install x264vfw, select it in VirtualDub, and press the Configure button you will get that dialog.

With just the defaults mentioned above, the encode did complete-- but at 16 Gb.

You used ffdshow's MJPEG encoder. That's not a very high compression codec.

Other techniques are needed to get it down to the desired 1.67 or Gb.

You need a high compression codec.

Are there options to specify the size and the program calculates what needs to be done?

You use a bitrate calculator to determine what bitrate will give you the size you want. Then specify that bitrate in the codec.

[loninappleton]

Which are the high compression codecs in or for Virtual Dub then? I seem to be asking for minute details
but one thing at a time.

I was looking at your steps provided--

In VirtualDub:

1) File -> Open Video File.
2) Video -> Full Processing Mode
3) Video -> Filters... -> Add. Select Resize filter. Set the size you want.
4) Video -> Compression... Select codec and configure it.
5) File -> Save as AVI.



I need a high compression codec, suggest a sample please. This would be the h264 or other.

I need a resize filter (again this seems like two different things but...) Which one of those might I try?

I'll look at your calculator info as well. It's late now. I'll resume tomorrow.

[jagabo]

Which are the high compression codecs in or for Virtual Dub then?

x264vfw.

I need a resize filter (again this seems like two different things but...) Which one of those might I try?

Use the Resize filter built into VirtualDub. This is for resizing the frame, not the file size.





In the Filter Mode pulldown are several options. In general the ones at the top are the least sharp, at the bottom most sharp.

[loninappleton]

Again , thanks for the visuals. Maybe others are just started as well.

I have the h264vfw codec installed.

I will navigate to the resize option. 1280x720 would then resize to 640x360 (?)


Today I'm just going to do a practice on the original (not editing) and resize and get the data from it with whatever the defaults are in the h264 codec. I hope this does not confuse me too much.
I think I can just dump the one that is 16Gb.


The h264 config says it will change the Bitrate to 800. Media Info tells me my original is 2997. That's a big jump downwards. Does this need adjustment?

[loninappleton]

I have another one running. That will take a couple hours according to the estimate.

In order

Select h264 from Compression list
Select Video Filter Resize to 640 360 ( when adding 640, 360 auto completes.)

Audio > Volume +149.6 %

Snip 11 minutes off beginning and I did not use the key frame but a simple visual edit.

h264 gave some hints which I didn't catch until the content was processing.
Recall it is set for 800 bitrate default. It said some frames might drop but can be fixed in three steps:

In h264 Configure:

Enable Virtual Dub Hack (a checkbox near bottom)
Enable File Output mode
Enable zero latency.


Are there presets available for this which are known or is each setup from scratch?

[jagabo]

I will navigate to the resize option. 1280x720 would then resize to 640x360 (?)

Use whatever size you want. 640x360 will keep the correct aspect ratio.

The h264 config says it will change the Bitrate to 800. Media Info tells me my original is 2997. That's a big jump downwards. Does this need adjustment?

Use a bitrate calculator to determine what bitrate will deliver the size you want.

I have another one running. That will take a couple hours according to the estimate.

Why don't you work with a 1 minute clip until you know what you're doing? You'll get much faster feedback. Each experiment will only take a few minutes rather than hours.

Select h264 from Compression list
Select Video Filter Resize to 640 360 ( when adding 640, 360 auto completes.)

Audio > Volume +149.6 %

Snip 11 minutes off beginning and I did not use the key frame but a simple visual edit.

h264 gave some hints which I didn't catch until the content was processing.
Recall it is set for 800 bitrate default. It said some frames might drop but can be fixed in three steps:

In h264 Configure:

Enable Virtual Dub Hack (a checkbox near bottom)
Enable File Output mode
Enable zero latency.

AVI isn't really a great container for h.264 video. Some settings can cause problems for some programs. Any one of those three options will take care of the problem that was indicated. All three are in the configuration dialog. The VirtualDub Hack is probably your best option there.

Are there presets available for this which are known or is each setup from scratch?

I don't think so.

[loninappleton]

Using a small clip is a good suggestion.

I have a long path to chart though. Sound was way off. Could this be due to those frames being dropped described in the 'hint' which h264 shows?

I can try the Hack as a start and see if the sound sync improves. Perhaps there is something in Virtual Dub for this--

Asking it another way: What should the right setting be in the audio tab of Vdub? I selected full stream for that as well. From my Media Info (shown above for the original) , should that have a specific setting to be in sync?

Vdub > Options > Sync to audio is prechecked

Interleave shows where a delay can be set.

Advise about whether any of this is a correct path forward.

[jagabo]

Sound was way off. Could this be due to those frames being dropped described in the 'hint' which h264 shows?

Yes.

I can try the Hack as a start and see if the sound sync improves. Perhaps there is something in Virtual Dub for this--

No. It's a problem with h.264 in AVI.

(audio) Interleave shows where a delay can be set.

If the hack for h.264 in AVI doesn't fully fix the audio sync problem that is where you will fix it.

[loninappleton]

Ok I'll push on with it adding operations as I go:

Hack first

then the audio delay (one way or the other-- I think the sound was behind the video.)
I can do the delay by using VLC which can adjust the audio to video on the fly then record that
number.

[jagabo]

If you're happy with the video after reencoding, you can remux the audio with a different delay in VirtualDub. That will be very fast and will not reencode anything.

File -> Open Video File (new video file with A/V sync problem)
Video -> Direct Stream Copy
Audio -> Interleaving... set audio delay
File -> Save as AVI

[loninappleton]

Today I downloaded the Bitrate calculator.

Some errors might have occurred from my not following the steps correctly. Today I used the seven step procedure with the original content (no editing) applying all that I could and will post the Media Info.

V-dub >Open file
Audio > Full processing
Audio > compression > used the available Microsoft ADPCM 48k 4 bit Stereo
Video > Full processing
Video > Filter > Resize > 640x 360
Video > Compression > H264 > Hack
Save as new item

Playback visually showed a delay needed of 300 ms (as close as I could peg it.)

With these settings size is dramatically reduced-- perhaps too far at 540 mb un-edited.
I have yet to use the Range option mentioned for editing and want to try that.


MediaInfo log will follow.

[jagabo]

Playback visually showed a delay needed of 300 ms (as close as I could peg it.)

Check to see if your source has an audio delay/advance.

With these settings size is dramatically reduced-- perhaps too far at 540 mb un-edited.

Once again, use a bitrate calculator to deterimine what bitrate will give the file size you want.

[loninappleton]

I will start with the calculator tomorrow. It feels a little bit like progress at least. There are so many options in Virtual dub I appreciate the assistance in sorting through it all.

Unfortunately in these communications there are inevitable false starts-- like my not knowing which Virtual Dub is which etc.

[loninappleton]

Just one question today about audio delays which I'm trying to correct in Virtual Dub.
Virtual Dub > Audio > Interleave preloads a default of 500 ms 'before the video starts. Should this be zeroed or how does it effect the sound sync?

Also on Interleave: Will it accept positive and negative values depending on if the audio is ahead or behind the video?

[manono]

Virtual Dub > Audio > Interleave preloads a default of 500 ms 'before the video starts. Should this be zeroed...

No, as it has nothing to do with the delay.

Will it accept positive and negative values...

Yes.

[loninappleton]

Just now I'm wondering if errors in my attempts have crept in and given erratic results.

The goal is to control as many variables as I can.

Example: you said that the h264 does not work well with AVI. I have seen that. Various samples produce one thing right but not another-- usually audio sync way off. I was getting dizzy yesterday just trying to figure out which way the audio was off. Analysis programs like Media Info tell nothing about such things. What is an alternative to the h264 even if not as much size compression is available?

Also the original is 25 frames per second. Not the default 24 (plus a fraction) shown in the
h264 codec. Could this be why my audio always goes off? And I have seen a completed attempt where I get no video at all when a delay is set.

This seems like trying to bend the h264 into working with AVI. Perhaps just a more stable
codec suite would work better.

For all this, I'm still trying to stabilize operation number one.

I have the 2.1Gb AVI

I want to snip an intro. I want to change the audio to a levelled style. That program works with a WAV only.

Snip first or demux and run the audio leveller?

If snip first, cut on keyframe or not?

[loninappleton]

I have been continuing to think about this problem of audio synchronization during a Virtual dub
processing routine to a smaller size.

The original screen cap is 25 fps. Conversion tools exist for Pal to NTSC. Might not this
be a first step to get Virtual Dub or other software more compatible with this AVI, Group of Pictures or otherwise?

I recall that Virtual Dub has some 25 fps options but do not know if they apply. Simply put,
Virtual dub has not been able to keep my audio in sync in any operation.


If a new topic is needed please advise.

[jagabo]

Since I haven't seen you captures I have no idea what's wrong. I suspect you dropped frames during capture because x264 is too slow. And that is the cause of your loss of audio sync. And the reason your captured video isn't a perfect 25 fps.

[loninappleton]

It's possible that the tool used to do the capture is the culprit.

I may just have to 'cut bait' on the task and stop thinking about it.

What besides the Media Info could you look at as an attachment? A clip? That's what the thread was originally about and for that I can say it was a success.

However passing clips around may violate the rules.

[manono]

What besides the Media Info could you look at as an attachment?

He already told you.

A clip?

Yes, a short 10-second or so piece directly from the source.

However passing clips around may violate the rules.

It won't. Fair Use allows for the sharing of short video clips without the permission of the copyright holder.

[loninappleton]

Always good to meet another Fair Use advocate.

Yes, I can find a short clip-- actually a bit of a PSA from the source.

Will work on making that the right length.

[loninappleton]

My first clip

This is from the original Part One (of two) original size 2.11 Gb.
Direct stream stream copy edit

[loninappleton]

The part two seems to have been 'dropped.' someway. I'll retrieve it. It looked like it went through.