avi to mpeg adventure using ffmpeg in linux text mode

[poisondeathray]

576 +46 +66 = 688 . I think it must be adding the padding after -target pal-dvd

[FulciLives]

DVD Resolutions are:

NTSC
720x480 or 704x480

PAL
720x576 or 704x576

There are other resolutions that can be used but these are the standard resolutions. Almost every commercial DVD uses 720x480 NTSC or 720x576 PAL

[FulciLives]

According to FitCD a resolution of 544x256 (assuming this is 1:1 pixel resolution) should be resized to 720x496 with a padding of 40 (on the top) and 40 (on the bottom). This will make a 16x9 720x576 PAL DVD compliant image with the correct aspect ratio.

Again FitCD is simply a tool to help one see how to properly resize a source for a destination type, or in this case, from AVI to PAL DVD.

*** EDIT ***
Your MediaInfo output on the source says the aspect ratio is 2.125 and that is what I'm getting in FitCD when I enter 544x256 using 1:1 pixel resolution so yeah my numbers above are correct.

Unfortunately it isn't going to look pretty because your resolution is fairly low (in the original). You might be better off making this a 4:3 WS PAL DVD instead of a 16x9 WS PAL DVD but only if the intended TV is a 4:3 TV

Resizing to 720x368 and padding the top 104 and the bottom 104 will give you a 4:3 WS PAL DVD but again this only makes sense if watching it on a 4:3 TV

[doru001]

688 is to high. 688 > 576

I'm thinking something went wrong with your padding

Yes, you are right, I did not see the Height in the output of mediainfo. Thank you for telling me. The trouble is that I can not guess how does ffmpeg choose the height as function of my parameters. For example:

-s 720x466 -padtop 2 -padright 0 -padbottom 2 -padleft 0

and

-s 720x464 -padtop 2 -padright 0 -padbottom 2 -padleft 0

both choose a height of 580.

[doru001]

According to FitCD a resolution of 544x256 (assuming this is 1:1 pixel resolution) should be resized to 720x496 with a padding of 40 (on the top) and 40 (on the bottom). This will make a 16x9 720x576 PAL DVD compliant image with the correct aspect ratio.

Again FitCD is simply a tool to help one see how to properly resize a source for a destination type, or in this case, from AVI to PAL DVD.

*** EDIT ***
Your MediaInfo output on the source says the aspect ratio is 2.125 and that is what I'm getting in FitCD when I enter 544x256 using 1:1 pixel resolution so yeah my numbers above are correct.

Unfortunately it isn't going to look pretty because your resolution is fairly low (in the original). You might be better off making this a 4:3 WS PAL DVD instead of a 16x9 WS PAL DVD but only if the intended TV is a 4:3 TV

Resizing to 720x368 and padding the top 104 and the bottom 104 will give you a 4:3 WS PAL DVD but again this only makes sense if watching it on a 4:3 TV

Thank you for your help. However, with 720x496 and a padding of 40 top and 40 bottom I get 720x656, and with 720x496 and a padding of 20 top and 20 bottom I get 720x616. It simply does not make any sense. Values are jumping any way they like.

[doru001]

576 +46 +66 = 688 . I think it must be adding the padding after -target pal-dvd

Then I can't use padding at all. Could be a big bug in my old version?

[FulciLives]

Thank you for your help. However, with 720x496 and a padding of 40 top and 40 bottom I get 720x656, and with 720x496 and a padding of 20 top and 20 bottom I get 720x616. It simply does not make any sense. Values are jumping any way they like.

576 + 40 + 40 = 656

So whatever ffmpeg commands you are using it seems to be adding the padding after resizing to 720x576
What you want is something that resizes 544x256 to 720x496 and then pads 40 on top/bottom to make it 720x576
But whatever you are doing ... it isn't working that way.
I don't know ffmpeg commands and I'm not about to learn so ... good luck.

[doru001]

I'm using now:

ffmpeg -i file.avi -target pal-dvd -s 720x464 -padtop 56 -padright 0 -padbottom 56 -padleft 0 -acodec ac3 -ab 448000 -mbd 2 -qscale 1.0 -aspect 16:9 file.mpg

As you see, I moved -target before -s, and now it is fine. Probably -target overrides -s if it is placed after it. Thank you poisondeathray for your idea about -target and FulciLives for your support. I suspect that the original movie is not actually 16/9, so I used my eye-based found 464 height, which I can only hope that will look fine on my tv (which is wide). I'll keep you in touch with the result.

[doru001]

So whatever ffmpeg commands you are using it seems to be adding the padding after resizing to 720x576
What you want is something that resizes 544x256 to 720x496 and then pads 40 on top/bottom to make it 720x576
But whatever you are doing ... it isn't working that way.
I don't know ffmpeg commands and I'm not about to learn so ... good luck.

-target imposes some presets, and if you want to modify some of those presets then you must do it after -target. Of course, I did not bother to read the man and I heavily relied on intracube, such that I did not know a thing of what I was doing there.

[intracube]

As you see, I moved -target before -s, and now it is fine. Probably -target overrides -s if it is placed after it. Thank you poisondeathray for your idea about -target and FulciLives for your support. I suspect that the original movie is not actually 16/9, so I used my eye-based found 464 height, which I can only hope that will look fine on my tv (which is wide). I'll keep you in touch with the result.

Sorry, I've been busy this afternoon - forgot to check in on this thread.

Glad you've got it sorted. There doesn't seem to be any logic to why the position of -target makes a difference here. If it's a bug, it could well have been fixed in later versions of ffmpeg.

and I heavily relied on intracube

uh oh - and I was having to give suggestions for this older version of ffmpeg blindly

But with regard to the scaling and padding, putting -target before those options doesn't make any sense. But, if it works...

EDIT: actually, it does make sense. If -target:
- always uses the original videos dimensions as a basis for calculating the re-scaling needed to make the resolution DVD compliant
- ignores any changes in frame size by using the -s and pad parameters
- applies what it thinks is the right scaling correction - but does this wherever it's placed in the argument list

That would explain what we're seeing.

[FulciLives]

I'm using now:

ffmpeg -i file.avi -target pal-dvd -s 720x464 -padtop 56 -padright 0 -padbottom 56 -padleft 0 -acodec ac3 -ab 448000 -mbd 2 -qscale 1.0 -aspect 16:9 file.mpg

As you see, I moved -target before -s, and now it is fine. Probably -target overrides -s if it is placed after it. Thank you poisondeathray for your idea about -target and FulciLives for your support. I suspect that the original movie is not actually 16/9, so I used my eye-based found 464 height, which I can only hope that will look fine on my tv (which is wide). I'll keep you in touch with the result.

If the aspect ratio is correct on the original AVI then my resizing numbers are correct.

However I have seen AVI files with an incorrect aspect ratio. For instance something that should be perfectly round (like the tire of a car) won't be and that's because the person who made the AVI managed to **** up the aspect ratio. In which case you have to eyeball it when resizing to fix their aspect ratio mistake.

However if the aspect ratio on the original IS correct (and things that should be perfectly circular are in fact perfect circles) then you have to keep it the same aspect ratio when resizing or you end up changing the aspect ratio.

I mention circular objects because that's one of the best ways to tell if the aspect ratio is off or not. Look for car tires or clocks (most are perfectly round) or the sun or anything like that which may be in the video.

Also don't get confused over 16x9 WS anamorphic enhancement and the real aspect ratio. For instance the original video, at 544x256, has an aspect ratio of 2.125:1 and my resizing numbers will keep the aspect ratio at 2.125 but make it 16x9 WS anamorphic enhanced.

Here's an example of what I'm talking about:

The following image is 544x256 and has an aspect ratio of 2.125 and is taken from an XviD AVI file


Now when you take this and convert it to PAL DVD with 16x9 WS anamorphic enhancement you get the following image:


Please note that the 2nd image is 720x576 but is stretched. That's 16x9 WS anamorphic enhancement. Now when this gets played back on a 16x9 WS TV then the image gets stretched out to the proper aspect ratio and becomes the following:



That last image is the same as the second one, but stretched out from 720x576 to 1024x576 and this is what a DVD player does when displaying a 16x9 WS anamorphic enhanced DVD. It's basically a trick to get more resolution out of the DVD spec. Of course in this case it doesn't look ultra sharp because the original source of the DVD was a low resolution video at 544x256

- John "FulciLives" Coleman

[intracube]

Just a quick update - the problem with ffmpeg and the -target option has been fixed in the last few months.

Not sure exactly when it was fixed; 0.11.1 has the problem, but a newly compiled version of ffmpeg from a current snapshot of the source code doesn't.

So I didn't actually need to submit a bug report yesterday. I was accidentally running the older version of ffmpeg instead of the up-to-date self-compiled version - and thought the bug was still present...

[doru001]

I mention circular objects because that's one of the best ways to tell if the aspect ratio is off or not. Look for car tires or clocks (most are perfectly round) or the sun or anything like that which may be in the video.

Also don't get confused over 16x9 WS anamorphic enhancement and the real aspect ratio. For instance the original video, at 544x256, has an aspect ratio of 2.125:1 and my resizing numbers will keep the aspect ratio at 2.125 but make it 16x9 WS anamorphic enhanced.

Here's an example of what I'm talking about:

Thank you, I finally understand what you say. Moreover, I can see the video correctly on a 4:3 computer monitor but probably it would be distorted on the WS TV, so I have to use your data.

The original scale is correct. I did use round objects to eye scale the video, indeed they are the best.

Indeed, the original has a low resolution. It has been compressed to fit a CD.

I'll post here the results.

[doru001]

Just a quick update - the problem with ffmpeg and the -target option has been fixed in the last few months.

Not sure exactly when it was fixed; 0.11.1 has the problem, but a newly compiled version of ffmpeg from a current snapshot of the source code doesn't.

So I didn't actually need to submit a bug report yesterday. I was accidentally running the older version of ffmpeg instead of the up-to-date self-compiled version - and thought the bug was still present...

It is a bug. Why would anybody want -target to cancel previous options?! Also, the manual did not mention -s as being set by -target, so it was a ride.

[doru001]

Short summary: -target after -s cancelled -s. Because of padding, the resulting image was too tall. Being too tall, it looked blurred.

Horizontal red lines on fast motion: they are also visible in the original video, but are very faint. mencoder without yadif sharpened the video, including the horizontal lines. This again made ffmpeg image look blurred, by contrast. mencoder with yadif fainted them back again. I don't know why.

Video formatting is not a walk in a park, but I start to like it. Thank you all for your great help.

PS: intracube: Why do you add -mbd 2 in ffmpeg? How did you get to this option?

[FulciLives]

One last comment I want to make about 16x9 WS anamorphic enhancement.

This is done so the image looks better on a 16x9 WS TV but the DVD player will resize the image to fit a 4:3 TV or a 16:9 TV so it will work and look proper either way. That is why you have to tell the DVD player what type of TV it is plugged into (in the set-up menu).

So in short you should always encode 16x9 WS anamorphic when you have a widescreen source UNLESS you never ever expect to watch it on anything BUT a 4:3 TV but if you ever then get a 16x9 TV you will curse yourself for not having made 16x9 WS DVD's LOL

OK just wanted to make sure that was clear!

[intracube]

It is a bug. Why would anybody want -target to cancel previous options?! Also, the manual did not mention -s as being set by -target, so it was a ride.

There are two separate bugs here:

1. With old versions of ffmpeg (like your version - 0.5.9) placing the -target option after -s and pad causes the image size to end up wrong (too tall in your case). As you've found, putting it before the -s and pad options is a workaround.

2. in more recent versions of ffmpeg, -target caused a different problem with the -vf (Video Filters). The source video would be resized (non-interlace aware scaling) before the video filters - for interlaced video, this caused the pixels of the odd/even interlaced scan lines to merge into each other and stopped de-interlacing filters like yadif from working. (Putting -target before/after the -vf filters didn't make any difference.)

Both these problems appear to be fixed. The old pad options no longer exist - they've been integrated into the -vf video filters. The second bug has only recently been fixed. You will need to wait for the next stable version of ffmpeg (after 0.11.1) or compile your own from source.

If you haven't read about ffmpeg's Video Filters - they're a relatively new feature and give a lot more control over the video. In addition to scaling, cropping and padding, there are now controls for colour correction, sharpening, and also higher quality de-interlacing with yadif, etc.

As I mentioned, some of the old options like padleft, padtop, etc have been moved to the video filters. To re-size and pad an image:

in older versions of ffmpeg:
-s 720x464 -padtop 56 -padright 0 -padbottom 56 -padleft 0

in newer versions of ffmpeg, to do exactly the same thing using the video filters:
-vf scale=720:464,pad=720:576:0:56

Each filter option is now in a comma separated list. Any number of filters can be listed together in this way.

Also, in older versions of ffmpeg there was only one option for de-interlacing (-deinterlace), and this gave poor results compared to de-interlace filters like yadif:

*right click and open image in new tab or window and make sure zoom is at 100% (1:1px)
**text should read "ffmpeg used to have more limited controls for adjusting the video compared to mencoder"

When the next version of ffmpeg is available (the version after 0.11.1) I'd recommend updating to it.

[doru001]

FulciLives: I have a question. I want to resize 544/256 to 1024/x. x=1024*256/544=481.8823529~=482. However, you say that I should use 496. Why?

intracube: Total disaster, of course. I needed to concatenate two input files, and my old ffmpeg does not do that. It multiplexes the input files, one video and one audio, or something like that (the man is incomplete). I went hunting for PPA's. Then I finally understood why is my ffmpeg so outdated. It has been a fork. The big boss went one way, the group of programmers another (http://askubuntu.com/questions/32189/what-are-the-implications-of-the-ffmpeg-libav-fork-for-users). This happened with disk writing utilities, too (http://ubuntuforums.org/showthread.php?t=1677034). This is bad, because the big boss controls the official distribution and makes life difficult to those who need the good version. So I went to the outcast ffmpeg (http://ffmpeg.org/download.html, https://launchpad.net/~jon-severinsson/+archive/ffmpeg). Of course, I rely on your example for the new version.

About deinterlacing, I would understand that image if I would have learned about it already. However, I do not need it now, I believe. mediainfo was supposed to discover it, right? Interesting enough, mediainfo does not say that output file is PAL. Does PAL result from a set of parameters reported by mediainfo?

[FulciLives]

FulciLives: I have a question. I want to resize 544/256 to 1024/x. x=1024*256/544=481.8823529~=482. However, you say that I should use 496. Why?

If you recall I made an XviD AVI with a resolution of 544x256 so that I had a file similar to the one you were working with. I think I even uploaded it here (see my post about this on page 1 of this thread) to give you the same file (in case you needed to play around with ffmpeg or HCenc and needed a similar source but one that was short and therefore could be encoded quickly ... my file is only a 53 second clip).

Anyway when I load this into FitCD it says to resize it to 720x496 (see FitCD image below)



FitCD has been around for years and it don't lie

Your confusion probably stems from the fact that DivX/XviD AVI files use 1:1 pixels (square pixels) whereas DVD uses rectangular pixels which obviously aren't 1:1 pixels NOT to mention that NTSC DVD and PAL DVD get resized differently. I mean 720x480 can be 4:3 for NTSC but for PAL it is 720x576 yet both are 4:3 ratios. Also 16x9 can fit in the same window but again they get resized differently. For instance PAL 16x9 at 720x576 gets stretched out to 1024x576 whereas NTSC 16x9 at 720x480 gets stretched out to roughtly 853x480

Anyway that is why tools like FitCD exist. It makes it fool proof to get your resizing correct.

[intracube]

Total disaster, of course. I needed to concatenate two input files, and my old ffmpeg does not do that. It multiplexes the input files, one video and one audio, or something like that (the man is incomplete).

The syntax to join several files together in recent versions of ffmpeg (on Linux):

ffmpeg -i concat:input1.mp4\|input2.mp4\|input3.mp4

...followed by the rest of the encoding parameters
*the resolution and framerate of the input files must match or concat won't work.
- the backslashes might not be needed on other operating systems

Then I finally understood why is my ffmpeg so outdated. It has been a fork. The big boss went one way, the group of programmers another (http://askubuntu.com/questions/32189/what-are-the-implications-of-the-ffmpeg-libav-fork-for-users). This happened with disk writing utilities, too (http://ubuntuforums.org/showthread.php?t=1677034). This is bad, because the big boss controls the official distribution and makes life difficult to those who need the good version. So I went to the outcast ffmpeg (http://ffmpeg.org/download.html)

^That's the official version. The forked version is http://libav.org/ I haven't used libav. I don't know how different the syntax is compared to ffmpeg.

About deinterlacing, I would understand that image if I would have learned about it already. However, I do not need it now, I believe. mediainfo was supposed to discover it, right?

An interlaced video could have been encoded as progressive and mediainfo will say it's progressive - even though it's actually interlaced. The only way to tell for sure is to use your eyes.

Interesting enough, mediainfo does not say that output file is PAL. Does PAL result from a set of parameters reported by mediainfo?

I'm not sure why your encoded files aren't reported as PAL - my DVD encoding tests all say PAL. I don't know where mediainfo gets this information from. Are you sure your video is 720x576 and 25fps?

Digital video shouldn't be called PAL as it refers to the analogue tv signal, but it's sometimes used as identification for 25fps video.

[intracube]

FulciLives: I have a question. I want to resize 544/256 to 1024/x. x=1024*256/544=481.8823529~=482. However, you say that I should use 496. Why?

Why do you want to resize to 1024x482?? The DVD resolution should be 720x576 (or 704x576).

As to the reason for 496px instead of 482 - some video codecs need the resolution to be mod16. 496 is mod16, 482 isn't.

I don't know why FitCD chooses 496 over 480 though.

If you posted some stills from your source video, we might be able to suggest what the aspect ratio should be.

[doru001]

*the resolution and framerate of the input files must match or concat won't work.

Thanks, I did not know that. And it is not clearly stated in the documentation.

^That's the official version.

Well, not for Ubuntu.

I haven't used libav. I don't know how different the syntax is compared to ffmpeg.

It is the old version, which I used until now. No filters etc. And more than two times slower, in my case.

An interlaced video could have been encoded as progressive and mediainfo will say it's progressive - even though it's actually interlaced. The only way to tell for sure is to use your eyes.

There is idet in ffmpeg. How should I use it?

I'm not sure why your encoded files aren't reported as PAL - my DVD encoding tests all say PAL. I don't know where mediainfo gets this information from. Are you sure your video is 720x576 and 25fps?

You are right, I had the wrong vertical size, 688.

[doru001]

Why do you want to resize to 1024x482?? The DVD resolution should be 720x576 (or 704x576).

That is just a calculation.

As to the reason for 496px instead of 482 - some video codecs need the resolution to be mod16. 496 is mod16, 482 isn't.

This makes sense.

If you posted some stills from your source video, we might be able to suggest what the aspect ratio should be.

How can I capture them?

[doru001]

Your confusion probably stems from the fact that DivX/XviD AVI files use 1:1 pixels (square pixels) whereas DVD uses rectangular pixels which obviously aren't 1:1 pixels NOT to mention that NTSC DVD and PAL DVD get resized differently. I mean 720x480 can be 4:3 for NTSC but for PAL it is 720x576 yet both are 4:3 ratios. Also 16x9 can fit in the same window but again they get resized differently. For instance PAL 16x9 at 720x576 gets stretched out to 1024x576 whereas NTSC 16x9 at 720x480 gets stretched out to roughtly 853x480

Anyway that is why tools like FitCD exist. It makes it fool proof to get your resizing correct.

I know about these now, I read http://en.wikipedia.org/wiki/Pixel_aspect_ratio.

[poisondeathray]

If you posted some stills from your source video, we might be able to suggest what the aspect ratio should be.

How can I capture them?

Why don't you post sample of the video? A few seconds . This will also help to clear up the interlace issue and non standard dimensions
-t is duration
-s is start time

eg.
ffmpeg -i input.avi -vcodec copy -acodec copy -t 00:00:20 output.avi

[doru001]

Why don't you post sample of the video? A few seconds . This will also help to clear up the interlace issue and non standard dimensions
-t is duration
-s is start time

eg.
ffmpeg -i input.avi -vcodec copy -acodec copy -t 00:00:20 output.avi

I am not sure that this would be legal.

It is -ss, -s is size (new resolution).

I believe that the computed resolution is correct, and I chose the best of two samples: one with yadif, the other without yadif. The best is the one without yadif.

[FulciLives]

Keep the clip around 30 seconds ... maybe 60 seconds tops ... and that is A-OK despite the source. Even if it is copyrighted it would fall under 'fair use'

[doru001]

The image I see on the dvdplayer is cropped on the left and right margins. Is is cropped a lot for 702:482 and less (I believe) for 720:496. Maybe I should add another 16 to 496?

[FulciLives]

This is what we call TV OVERSCAN

http://en.wikipedia.org/wiki/Overscan

If you have a modern TV like some sort of flat panel LCD or Plasma etc. then you might be able to turn it off but if it is an older tube type TV or some sort of rear projection then you cannot.

[doru001]

This is what we call TV OVERSCAN

http://en.wikipedia.org/wiki/Overscan

If you have a modern TV like some sort of flat panel LCD or Plasma etc. then you might be able to turn it off but if it is an older tube type TV or some sort of rear projection then you cannot.

It is an LCD but how can I turn it off? (I'll read the wikipedia, too, thanks four your answer.)
OK, so I turn it off from TV.
Or else, maybe I should pad the image on the left and right sides, too, with some unknown amount.