My videos are 1920x1080 recorded with high ISO (3200) using smartphone (to get bright view, backlight scene mode). It produce a lot of noise. I try many video filter but all of them produce blur similar to when we reduce the resolution in half then increase it back again.
Is there a good video noise filter that only remove noise without producing blur?
Because if it produce blur, I would prefer to not do any filtering at all.
I have tried video filter:
nlmeans=s=30:r=3:p=1
vaguedenoiser=threshold=22:percent=100:nsteps=4
owdenoise=8:6:6
hqdn3d=100:0:50:0
bm3d=sigma=30:block=4:bstep=8:group=1:range=8:mstep=64:thmse=0:hdthr=5:estim=basic:planes=1
dctdnoiz=sigma=30:n=4
fftdnoiz=30:1:6:0.8
All produce blur, some even worse. I have to use strong setting to make the noise moderately removed. I end up halving the resolution and use remove grain then scale it up again. This is much better for me than all the above method (pp filter is used to reduce size without reducing image detail):
scale=960:540,removegrain=3:0:0:0,pp=dr/fq|8,scale=1920:1080
code example
FOR %%G IN (*.jpg) DO "ffmpeg.exe" -y -i "%%G" -vf "nlmeans=s=30:r=3:p=1" -qmin 1 -qmax 1 -q:v 1 "%%G.jpg"
Part of the image
The image:
To help with blur, I always use unsharp to sharpen the image after nlmeans. Below are the parameters I find work best on old grainy movies, or 4K transfers of old movies that create unacceptable grain. It seems to work quite well. For 4K movies, it almost makes them as good as the 1080p Blu Ray versions.
nlmeans=s=1:p=7:pc=5:r=3:p=3
unsharp=7:7:2.5
Related
I have some videos taken of a display, with the camera not perfectly oriented, so that the result shows a strong trapezoidal effect.
I know that there is a perspective filter in ffmpeg https://ffmpeg.org/ffmpeg-filters.html#perspective, but I'm too dumb to understand how it works from the docs - and I cannot find a single example.
Somebody can show me how it works?
The following example extracts a trapezoidal perspective section from an input Matroska video to an output video.
An estimated coordinate had to be inserted to complete the trapezoidal pattern (out-of-frame coordinate x2=-60,y2=469).
Input video frame was 1280x720. Pixel interpolation was specified linear, however that is the default if not specified at all. Cubic interpolation bloats the output with NO apparent improvement in video quality. Output video frame size will be of the input video's frame size.
Video output was viewable but rough quality due to sampling error.
ffmpeg -hide_banner -i input.mkv -lavfi "perspective=x0=225:y0=0:x1=715:y1=385:x2=-60:y2=469:x3=615:y3=634:interpolation=linear" output.mkv
You can also make use of ffplay (or any player which lets you access ffmpeg filters, like mpv) to preview the effect, or if you want to keystone-correct a display surface.
For example, if you have your TV above your fireplace mantle and you're sitting on the floor looking up at it, this will un-distort the image to a large extent:
ffplay video.mkv -vf 'perspective=W*.1:0:W*.9:0:-W*.1:H:W*1.1:H'
The above expands the top by 20% and compresses the bottom by 20%, cropping the top and infilling the bottom with the edge pixels.
Also handy for playing back video of a building you're standing in front of with the camera pointed up around 30 degrees.
I want to add a film grain effect using FFMPEG if possible.
Taking a nice clean computer rendered scene and filter for a gritty black and white 16mm film look. As an example something like Clerks https://www.youtube.com/watch?v=Mlfn5n-E2WE
According to Simulating TV noise Ishould be able to use the following filter
-filter_complex "geq=random(1)*255:128:128;aevalsrc=-2+random(0)"
but when I add it to my ffmpeg command
ffmpeg.exe -framerate 30 -i XYZ%05d.PNG -vf format=yuv420p -dst_range 1 -color_range 2 -c:v libxvid -vtag xvid -q:v 1 -y OUTPUT.AVI
so the command is now
ffmpeg.exe -framerate 30 -i XYZ%05d.PNG -vf format=yuv420p -dst_range 1 -color_range 2 -c:v libxvid -vtag xvid -q:v 1 -y -filter_complex "geq=random(1)*255:128:128;aevalsrc=-2+random(0)" OUTPUT.AVI
I get the message
Filtergraph 'format=yuv420p' was specified through the -vf/-af/-filter option for output stream 0:0, which is fed from a complex filtergraph.
-vf/-af/-filter and -filter_complex cannot be used together for the same stream.
How can I change my ffmpeg command line so the grain filter works? Additionally, can I add a slight blur too? The old 16mm looks more like blurred then grainy.
Thanks for any tips.
I just needed to make a film grain and wanted something "neater" than just randomizing every pixel. Here's what I came up with: FFmpeg film grain.
It starts with white noise:
Then it uses the "deflate" and "dilation" filters to cause certain features to expand out to multiple pixels:
The effect is pretty subtle but you can see that there are a few larger "blobs" of white and black in amongst the noise. This means that the features of the noise aren't just straight-up single pixels any more. Then, that image gets halved in resolution, because it was being rendered at twice the resolution of the target video.
The highest-resolution detail is now softened, and the clumps of pixels are reduced in size to be 1-2 pixels in size. So, this is the noise plane.
Then, I take the source video and do some processing on it.
Desaturate:
Filter luminance so that the closer an input pixel was to luminance level 75 (arrived at experimentally), the brighter the pixel is. If the input pixel was darker or brighter, the output pixel is uniformly darker. This creates "bands" of brightness where the luminance level is close to 75.
This is then scaled down, and this is where the level of noise is "tuned". This band selection means that we will be adding noise specifically in the areas of the frame where it will be most noticed. Not adding noise in other areas leaves more bits to encode the noise.
This scaled mask is then applied to the previously-computed noise. In this screenshot, I've removed the tuning so that the noise is easily visible:
The areas not selected by the band filter are greatly scaled down and are essentially black; the noise variation fades to nothing.
Here's what it looks like with a scaling factor of 0.32 -- pretty subtle:
I then invert this image, so that the parts with no noise are solid white, and then areas with noise pull down slightly from the white:
Finally, I pull another copy of the same source video, apply this computed image to it as an alpha channel and overlay it on black, so that the film grain dots, which are slightly less white, become slightly darker pixels.
The effect is pretty subtle, hard to see in a still like that when it's not moving, but if you tune the noise way up, you can get frames like this:
The filters "geq=random(1)*255:128:128;aevalsrc=-2+random(0)" is for white noise
For "a gritty black and white 16mm film look", you want something like instead,
-vf hue=s=0,boxblur=lr=1.2,noise=c0s=7:allf=t
The format you specified is a filter, and all filters applied on an input should be specified in a single chain, so it should be,
-vf hue=s=0,boxblur=lr=1.2,noise=c0s=7:allf=t,format=yuv420p
See filter docs at https://ffmpeg.org/ffmpeg-filters.html for descriptions and list of parameters you can tweak.
I want to convert a 1080p to 720p and also lower resolutions eventually.
I have been using ffmpeg for all my video processing activities so far, and would simply approach this task using the following command:
ffmpeg -i tos.mov -vf scale=-1:720 tos_0x720.mov
I understand that this will rescale my video to a new frame size having 720 pixels set as a fixed height and the width dynamically calculated.
What I am not sure about are the implications regarding the quality factors of the video when using ffmpeg this way.
Is it valid to assume that running this command will output a perfect HD 720p quality video?
What would be a benefit of using dedicated video conversion software to accomplish my goal compared to running the above command?
You can choose which scaling algorithm to use by setting the flags option in the scale filter. Some algorithms work better for up-scaling (bilinear) while others are better for down-sampling (bicubic, lanczos). Some are better for sharp graphics, others for gradual changes, some are faster and some are slower.
I think the default value for flags downsampling is bicubic, while some people recommend lanczos.
To set the flag use:
-vf scale=-1:720:flags=lanczos
Commercial video conversion software use the same algorithms. For eg. Adobe Premiere used variable-radius bicubic for Maximum Render Quality. They might help you choose one ore another depending on what you're after (speed vs. quality) and they may provide tweaks to reduce artifacts resulting from scaling.
There's a lot of literature covering the different algorithms.
I want to display the kinect color frame in wpf with full screen , but when i am trying it ,
I got only very less quality video frames.
How to do this any idea??
The Kinect camera doesn't have great resolutions. Only 640x480 and 1280x960 are supported. Forcing these images to take up the entire screen, especially if you're using a high definition monitor (1920x1080, for example), will cause the image to be stretched, which generally looks awful. It's the same problem you run into if you try to make any image larger; each pixel in the original image has to fill up more pixels in the expanded image, causing the image to look blocky.
Really, the only thing to minimize this is to make sure you're using the Kinect's maximum color stream resolution. You can do that by specifying a ColorImageFormat when you enable the ColorStream. Note that this resolution has a significantly lower number of frames per second than the 640x480 stream (12 FPS vs 30 FPS). However, it should look better in a fullscreen mode than the alternative.
sensor.ColorStream.Enable(ColorImageFormat.RgbResolution1280x960Fps12);
I'm new to Video technology, so any feedback (such as if I've underspecified the problem) would be greatly appreciated.
I need to display an animation (currently composed of about a thousand PNGs) on Windows and am trying to determine the best video codec or parameters for the job.
Video playback must be smooth at 30 fps
Output display is 1920x1080 on a secondary monitor
Quality does not matter (within limits)
Will be displaying alpha blended animation on top, so no DXVA
Must run on older hardware (Core Duo 4400 + nVidia 9800)
Currently using DirectShow to display the video.
Question:
Is it easier on the CPU to shrink the source to 1/2 size (or even 1/4) and have the CPU stretch it at run time?
Is there a video codec that is easier on the CPU than others?
Are there parameters for video codecs that mean less decompression is required? (The video will be stored on the HD, so size doesn't matter except as it impacts program performance).
So far:
- H.264 from ffmpeg defaults produces terrible tearing and some stuttering.
- Uncompressed video from VirtualDub produces massive stuttering.
There are so many different degrees of freedom to this problem, I'm flailing. Any suggestions by readers would be much appreciated. Thank you.
MJPEG should work. I used it for 1080i60 some 3 years back, and the playback was never an issue. Even encoding worked on-the-fly with a machine of quite similar performance to what you describe.
File size will be about 10MB/s for good quality video.
Shrinking the video will help, because if you are drawing the video to screen using e.g. DirectX, you can use the GPU to stretch it.