9
votes
Is there any AI upscale tool for videos?
There's a few options I've seen listed at
https://sites.google.com/view/aiupscalingtutorials/ai-upscaling:
(in no particular order)
1. ESRGAN
An open source AI upscaler (super sampler) based on a ...
- 342
8
votes
Accepted
What's the difference between "visually lossless" and real lossless and what does this mean for future encodes?
Technically lossless, or real lossless, means that when the output is decoded by a conformant decoder, the result is mathematically identical to the input.
Visually lossless is a non-rigorous term ...
- 33.8k
4
votes
Accepted
What deinterlacing filter should I use to encode/compress a PAL MPEG-2 576i 25fps raw file?
I don't agree that the other answer is a good idea in general, because "-vf yadif" will drop half the frames, thus resulting in a poor substitute of the original footage. Here is the thing: 576i25 ...
- 275
4
votes
Video compression- how to prioritize one area over another?
This is an interesting question, but I don't think that you will find a good solution without changing your inputs (the video elements you are using). I'm not aware of any software that allows you to ...
- 71
4
votes
Accepted
Camera flash produces unwanted artifacts on the video
This is actually a collateral effect of the concept of rolling shutter. Most video devices do not expose all the frame area at once. They expose starting from one side and (up or down) and move from ...
- 1,212
4
votes
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Producing small H.264 files with Adobe Media Encoder vs ffmpeg/libx264
Adobe licenses its H.264 encoder from Mainconcept, which doesn't do that well at low bitrates. x264 is pretty much the frontier when it comes at low size output for a given quality target, or quality ...
- 33.8k
4
votes
Accepted
What does the tag "-tag:v hvc1" means?
The FFMpeg document gave the idea of using the tag option with a FourCC code, and H.265/HEVC Video Encoding Guide gave the idea of Final Cut and Apple stuff compatibility. The hvc1 is defined to ...
- 847
3
votes
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Are JPEG compression and H.264 intraframe compression the same process?
This is a complex topic, so best to link and excerpt
From https://sonnati.wordpress.com/2010/10/19/h-264-for-image-compression/
H.264 contains a number of new features that allow it to compress
...
- 33.8k
3
votes
Accepted
Does increasing the framerate while not changing the content affects compression quality?
This depends on the specific encoder, and the compression standard, by itself, may not have anything to say about it.
x264, which encodes to H.264, takes frame duration, into account, in its ...
- 33.8k
3
votes
Archiving raw video
The way you have worded the question makes it difficult to answer. I keep all mine in default format, because disk space is so cheap. I have a bunch of 2 terabyte drives to store it on.
If you want ...
- 2,315
3
votes
Reencoding H.264 to H.264 made it 40% larger
You are using a quality based variable bitrate compression factor on something that already has artifacts. That means it is going to attempt to preserve the video exactly as it is, artifacts included ...
- 19.4k
3
votes
How does the h.264 encoder determine where to put i-frames?
This is a complex topic, with the exact algorithm unique to each encoder.
Below is a pseudocode explanation from a x264 developer. B-frames aren't accounted for, but basic logic should be similar.
...
- 33.8k
3
votes
Compressing of DSLR video
Theoretically
Current DSLRs use H.264 compression for their video. Optimizing an already compressed image without losing quality is something commonly done for GIF, PNG or JPEG still images, and while ...
- 803
3
votes
3
votes
What's the difference between "visually lossless" and real lossless and what does this mean for future encodes?
In addition to "visually lossless", there's the concept of "visually almost lossless":
"Visually almost lossless" is usually established by static side-by-side viewing. ...
- 131
3
votes
Software that captures and compresses simultaneously
Most consumer video recording software I know compresses on capture. Mpeg and others can be configured for lower quality if you want greater compression, but unless you are recording a plain black ...
- 2,315
3
votes
Accepted
Is video output in YUY2 color space lossless if the input is sRGB?
It's a bit of a semantics game. The YUY2 video mode is not "compressed," but it won't result in a bit-exact copy of RGB input. The luminance is full resolution in that mode, but the ...
- 486
3
votes
Accepted
Video artifact removal and restoration - How can it be done? (Really?)
If I understand you correctly, then most of the restoration goals will be impossible to be reached. While my knowledge of existing videos tools is not extensive, I am still pretty sure such a software ...
- 1,421
2
votes
Trading off resolution vs quality
Decreasing the size a little won't help much, decreasing it a bit more induces a fair bit of aliasing (unless it smooths it also) butchering the quality without much gained.
Cutting the size 50% will ...
- 869
2
votes
Compressing of DSLR video
Without affecting quality, and presuming your CPU and GPU are fast enough, utilizing the x265 / HVEC encoding library may be the best option. This can be done with Handbrake or FFmpeg, it can be a ...
- 197
2
votes
Is there a way to improve quality for videos with snow/confetti/LCD in background?
Yes this feature exists, but it is not widely used yet.
Texas Instrument developped such solution, called SmartCodec, which looks to be implemented in a Samsung video surveillance system: Megapixel ...
- 163
2
votes
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Prediction and Motion Estimation
The prediction comes in when actually adding the motion estimation to both frames t and t+1. Consider a video of a ninja cutting a melon in half, but shot at a very short shutter speed, so as to ...
- 4,730
2
votes
Accepted
Please Explain the Codecs in my Example
So codecs compress and decompress videos, right?
COmpress DECompress. Yep. Just like with text encoding, e.g. ascii or unicode, but with video you take a raster (grid of pixels) and turn that into a ...
- 13.8k
2
votes
Chroma subsampling notation - rules
Yes, there are.
Let x:y:z is a chroma subsampling. Then
x = 4
So the begin of the notation is 4:.
y|x (y is a divisor of x)
So there are 3 possibilities for the first two numbers: 4:1: or 4:2: or 4:...
- 1,652
2
votes
Accepted
Different rate distortion curves for two videos encoded with same parameters in FFMPEG
The difference in the content of the two samples could explain the different performance of the codec. A given configuration of a codec might perform well for a static shot but not perform well for ...
- 2,404
2
votes
Accepted
How do I avoid objects having flickering edges when I encode a screen recording to mp4 using x264 and ffmpeg?
The parameter that seems to have the greatest impact on removing this artifact (for the type of content in the original post), while allowing higher CRF values is deblock. Using -deblock -3,-3 allowed ...
- 95
2
votes
Accepted
Lossless and lossy compression techniques
OK, MPEG is the Motion Picture Experts Group, it's a group of people who decide stuff about moving picture standards. Some of these standards are well known, such as MPEG2 which includes the standards ...
- 13.8k
2
votes
Using ffmpeg to add height (as black bars) to video file without quality loss
You'll have to manually set encoding parameters.
ffmpeg -i input.mkv -filter:v "pad=3840:2160:0:280,setsar=1" -crf 18 -preset faster -c:a copy my_output_video.mkv
The CRF option sets the tradeoff ...
- 33.8k
2
votes
Accepted
Some H.264 videos that I have seem to have excessive bitrate, is there a way to determine/find their recommended bitrate?
So how, if even possible, do I correctly determine the bitrate of a
video if it seems excessive?
There's not a "correct" way. That's why every encoder you come across presents bitrate as an option ...
- 4,544
2
votes
What's the difference between "visually lossless" and real lossless and what does this mean for future encodes?
How did they decide that?
To answer literally, I am the original author of that article and added the claim years ago that CRF ~18 is visually lossless (but not technically lossless like CRF 0). I ...
- 10.3k
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