IMAGE to VIDEO problems

[brutoloco]

Once JPG images (I didin't tried other formats) are being processed to any video, the colors are changed, lowers a bit of gamma and some stuff. I tried to correct it with filters, but finally I couldn't. My head burned thinking about the problem is about gamma correction. I didin't found any filter solution. But seems related to it.


I discovered that other programs doesn't make any change to the images to the video. For example, I tried Virtualdub, and did not change any color/contrast/gamma/brightness of the image once they are converted to video.

VirtualDub: VIDEO FRAME ≅ ORIGINAL IMAGE

Avidemux: VIDEO FRAME ≠ ORIGINAL IMAGE

It's not easy to notify the difference if you are not looking for it.

For reproduce this bug, make a short video with a bunch of numbered images, once the video is open. Open in any player, like vlc or mpch, and click "next frame" and copy the first frame. Then compare it with the first image. Copy the first image to any isolated folder with the frame taken from the video. Open it and chage one to other with right left arrows.

I hope this would be solved, I found very useful the tool about converting images to video.

Also, there is Another Problem with this function:

The maximum number of images is 99999. Which is a low number if we are trying to encode an entire film, for example. There is a workaround doing in parts, and then mixing them.


This is my first post. Used this program long time ago. And I very appreciate it.

Thanks you

[eumagga0x2a]

First of all, please use the latest 2.7.7 nightly, some color conversion issues resulting in colors being slightly off with the "Qt" renderer as used for filter preview have been solved post-release.

This would not address the luminosity range problem between JPEG (0-255) vs MPEG (16-235) you noticed, however. You can automatically stretch the range by adding the "Contrast" video filter and enabling the MPEG->PC option. Anyway, this is a known issue, on my todo list.

What purpose should exporting each frame of an entire movie as JPEG images serve? Maybe exporting only keyframes would make more sense? I guess, both should be achievable with a bit of python scripting. Will look into it later.

The maximum number needs to be bound (with 99999, we are already beyond the limits of the worst possible filesystem – FAT32 – so it doesn't matter really), but each digit reduces the number of characters available for the actual name.

[brutoloco]

First of all, please use the latest 2.7.7 nightly, some color conversion issues resulting in colors being slightly off with the "Qt" renderer as used for filter preview have been solved post-release.

This would not address the luminosity range problem between JPEG (0-255) vs MPEG (16-235) you noticed, however. You can automatically stretch the range by adding the "Contrast" video filter and enabling the MPEG->PC option. Anyway, this is a known issue, on my todo list.

What purpose should exporting each frame of an entire movie as JPEG images serve? Maybe exporting only keyframes would make more sense? I guess, both should be achievable with a bit of python scripting. Will look into it later.

Hi,

I did what you said, the last nightly 2.7.7 apply the same distortion to the video. The MPEG->PC filter makes something like double the same distortion. So I deducted that the opposite PC->MPEG would be a solution. I applied inversed parameters in Contrast filter, that the button "PC->MPEG" applies , and the result looks very similar to the original image. But is not exactly the same. Adjusting this parameter could be a workaround. Nice to know it. Would not have discovered it if you didn't said that.

I found another encoder program called Hybrid which doesn't apply any distorion, and doesn't have a limit on the number of images converted to video. Anyway this program (Hybrid) is something like a frankenstein monster, have a lot of bugs and crashes a lot. Still prefer to use Avidemux if were possible in the future, for the same task.

The maximum number needs to be bound (with 99999, we are already beyond the limits of the worst possible filesystem – FAT32 – so it doesn't matter really), but each digit reduces the number of characters available for the actual name.

I don't think I understand your response. If I put the first image 000000.jpg of something that is like a film of 1 hour finishing in 130000.jpg, it would add images until 099999.jpg. But It doesn't notice it to the user, if anyone don't check the ending, wouldn't notice it. Maybe if possible to add the rest of images after, but I didin't tried it.

Maybe you ask why I'm doing this. It's about remaster videos, which seems more useful to apply filter and encode to images.

Bye


[EDIT: I found that, in Hybrid when if you choose Avisynth instead of VapourSynth, using x264 codec, it does apply the same contrast+light distortion. May be this a hint]