12
votes
Accepted
Big difference in the video file size after the conversion (.mov to .mp4)
Let me explain you from scratch.
MOV, MP4, AVI, MKV etc all these are just containers, It is just kind of wrapper which contains audio, video, text, metadata file together as one file. It does not ...
- 181
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 ...
- 31.4k
8
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 ...
- 330
7
votes
Can H264 achieve "equivalence" with ProRes 422?
Has anyone done or seen any tests comparing Apple ProRes 422 with high-bitrate H.264?
No, but I can tell you that x264 can get as close to lossless as you want (or even mathematically lossless, with -...
- 2,690
7
votes
Accepted
Techniques for compressing a slideshow presentation video?
x264 is the best-in-class encoder for generating H.264 video streams and you can use it via ffmpeg, a command-line tool, to encode to a small-sized file. Get a binary from here - opt for the latest ...
- 31.4k
5
votes
Accepted
Loss of quality while adding subtitle via FFmpeg
As you are hardcoding subtitles, the video (with the subtitles added) will be re-encoded.
You can use the CRF rate control method to modulate the quality of the output.
So, start with
ffmpeg -i ...
- 31.4k
5
votes
Will Compression/Format of Audio Change when Uploaded to YouTube?
Youtube generally reencodes all videos you upload to youtube to ensure compatibility across various platforms and to provide smaller versions of the videos for users with slow internet connections. So ...
- 5,392
4
votes
Video codec for simple animation?
I read up a bit and made some experiments with lossless codecs, getting decent results. I'd be interested in comments on this, especially if there are lossless or lossy alternatives that I overlooked.
...
- 231
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 ...
- 1,152
4
votes
Accepted
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 ...
- 31.4k
3
votes
Accepted
Convert 1920x1080 Video to 720x480 With Letterboxing
You can use ffmpeg, a free command-line tool, to do this:
Without letterboxing, NTSC wide pixel-aspect
ffmpeg -i input.mp4 -vf "scale=720x480,setdar=16/9" -r 30000/1001 -c:v libx264 -crf 20 -c:a aac ...
- 31.4k
3
votes
Accepted
Which measurements can I take using which programs to exploit the already low quality and save as much space as possible?
There are a few video quality metrics available for you to use, primarily SSIM and also PSNR. You can use ffmpeg to convert the video and then compare the output.
Step 1 Convert the video
ffmpeg -i ...
- 31.4k
3
votes
Accepted
x265: Is it possible to re-compress HEVC video without quality loss?
In strict mathematical terms, no.
In terms of maintaining an acceptable image quality, yes. If you use CRF 18 and a preset like ultrafast now, you should be able to get a smaller acceptable file with ...
- 31.4k
3
votes
Reduce render file size in After Effects
You need to change the encoding settings. By default, AE uses the AVI animation codec, which is very good at retaining quality but creates incredibly large files. Using an intermediary codec like ...
- 1,004
3
votes
Accepted
Recording of Lectures: Tips for compressing video with mostly still images
Modern video codecs are already very good at dealing with temporal redundancy. You probably don't need to do anything extra unless you're targetting an extremely low bitrate. You could probably go ...
- 2,690
3
votes
How to compress videos for a website?
I recommend not to host the video files on your web server, but to upload them to YouTube and only embed the YouTube link on your web page. You can even define that your videos won't show up on ...
- 797
3
votes
How to specify CRF quality settings for different encoding software
Any decent encoder can hit a target bitrate (with 2pass), but still spend the bits intelligently to achieve similar quality throughout the file. x264 2pass figures out what CRF will give the desired ...
- 2,690
3
votes
Add noise to video while maintaining compressibility
As you say, noise by definition doesn't compress well. You can try different types of noise in FCP. The Add Noise filter has several choices - Gaussian is a reasonable simulation of film grain, but ...
- 2,146
3
votes
YouTube Compression: Why?
You should upload the highest quality your tubes can afford. The current YouTube help text on uploads is misleading. It states:
Your videos will process faster if you encode into a streamable file ...
- 131
3
votes
Converting WMV to MP4
All that matters is if the MP4 looks good to you. Of course, you may be able to compress more. There is no set bitrate to use. More complex or rapidly changing visuals require greater bitrate. Most ...
- 31.4k
3
votes
Accepted
How do you dramatically reduce the size of a video while keeping the quality as much as possible?
I'm not familiar with handbrake, but this is basically a math problem.
First, you have to decide on a codec. One of the 'best' codecs in regards to quality/filesize-ratio as well as device-...
- 5,392
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
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.
...
- 31.4k
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 ...
- 2,283
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 ...
- 19.3k
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 ...
- 31.4k
3
votes
Accepted
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
...
- 31.4k
3
votes
Only top scored, non community-wiki answers of a minimum length are eligible