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35 votes
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How to downsample 4k to 1080p using ffmpeg while maintaining the quality?

The default settings for ffmpeg are very low quality, and since you don't specify any codec or quality parameters it's just using the defaults (I don't know why the devs don't fix that because it ...
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7 votes
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H.264 Max Resolution

One of the bits of information associated with a H264 stream is its level. The level informs the decoder the computational resources needed for a successful decode. Turns out that the highest level 5....
  • 30.6k
6 votes

H.264 Max Resolution

H.264/AVC is not limited for 4K in terms of max resolution as it supports DCI 4K (4092x2160) @ 60 fps at Level 5.2. For example Sony already uses XAVC which is exactly 4K AVC. For a while the max ...
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6 votes

Does 4K impact quality when filming in low light? (other parameters being equal)

There are three key factors in your cameras low light performace: 1. Lens (Aperture) The lower your f-stop, the more light gets through to the sensor, you will also have a very shallow (narrow) Depth ...
5 votes

How to downsample 4k to 1080p using ffmpeg while maintaining the quality?

Convert 4k to 1080 (no change in codec) ffmpeg -i input4kvid.mp4 -vf scale=1920:1080 -c:a copy output1080vid.mp4 Convert h.264 to h.265 (no change in resolution) ffmpeg -i input.mp4 -c:v libx265 -...
5 votes

Does 4K impact quality when filming in low light? (other parameters being equal)

Yes, if you record a video in 4K, then downsize to 1080p, the image will look much clearer than if you shot the video on a 1080p camera. You can also zoom in up to 200% and still retain the quality in ...
4 votes

Why do cinema cameras cost too much?

Look at it from a data rate point of view: a GH4 records 4K at 100 Mbps. A RED Carbon Fiber WEAPON records at 300MBps. That's 24x the data rate. Look at how very much more expensive it is to ...
4 votes
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Why does 8K have 16 times the pixels compared to 1080p?

First off, 2K is not 1440p, it is 2048 x 1080p. 4K is 4096 x 2160p. (Note that UHD = 3840 x 2160p...4K and UHD are like US and Canadian dollars--they are both dollars, but they have different values....
4 votes
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What is the origin of 4K term?

According to Wikipedia ,Digital Cinema Initiatives originated the term 2K in 2002 for a digital film format of 2048 x 1080. 2048 is commonly referred to as 2K in the digital world. It logically ...
4 votes
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.mkv file not playing in HEVC/H.265 supported player

Both files that don't play feature Opus as the audio codec. As per this site, Opus is not one of the supported audio codecs. Transcode the audio: ffmpeg -i in.mkv -c:v copy out.mkv
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3 votes
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DJI Osmo X3 vs Canon 5D Mk III for easier chroma green screen keying

The key to pulling a good key is a clean separation between key and subject. All things being equal, higher resolution will give a sharper edge between key and subject, which is good. But that's ...
3 votes
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How to make Sony Vegas Pro 13 work on a 4K display

There's apparently a hack which alters the Vegas executable to solve this problem. There's a setting of dpiAware in the application manifest which falsely tells Windows that Vegas is DPI aware and ...
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3 votes
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Downscaling 4k to 1080p in Premiere Pro, Image Zooming 2x

Changing the preference doesn't change any clip settings retroactively. But once you have set it, and then create a new project and a new sequence, and when you freshly import your 4K clip and drop ...
3 votes

How should I encode my 4K video stream?

As mentioned by @Mulvya, I think the issue is the "slow" preset. One option is encoding a compressed stream that is also lossless. For example, the x264 encoder can do this using "-preset ultrafast -...
3 votes

Why do cinema cameras cost too much?

The image processing of cinema cameras is done with fairly inexpensive FPGA chips, that doesn't explain a 50.000€ price difference between I.e. a gh4 and a arri Alexa. The FPGA chip used in blackmagic ...
3 votes
Accepted

Convert resolution 4096x2304 to 3840x2160 keeping the quality the same

Judge based on the quality rather than the bitrate value. Use CRF mode encoding and if the quality isn't what you can accept, decrease the CRF value. ffmpeg -i "%%a" -s 3840x2610 -c:v libx264 -crf 18 ...
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3 votes

Why do cinema cameras cost too much?

You are probably comparing cameras that record compressed 4k video with cameras that record uncompressed video, i.e. RAW footage. The ARRI ALEXA and RED Epic belong in the latter category. The ...
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3 votes

Do Film Makers Want 4k?

In my opinion, the market for 4k delivery is still very small, but that doesn't mean its useless. Shooting at a higher resolution than the delivery resolution allows you to recompose shots without ...
3 votes
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Is 4K good enough to choose for special footage such as weddings?

Where are you planning on exhibiting the footage? In my experience, the average consumer has a low-quality TV they bought because of the price, and they have the factory settings that look awful ...
  • 2,146
3 votes

Tips to start making a little production

The minute you said "no lighting" you violate the premise of "look as professional as it could be and not too amateur". Lighting is not only about ensuring there are enough photons to actually record ...
3 votes

Downscaling 4K YUV420 to 1080p YUV444 with ffmpeg introduces red tint

I dug further and after reading the entire topic at Personal View, I found that user willyfan suggested to add in_range=full to both first scale arguments to correct a color shift that he also ...
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3 votes

Best render settings for broadcast/4k TV

The reason for mastering out to an uncompressed / minimally lossy format is so that you have a master copy, which you can then use to make other copies, without generation loss, or having to re-render....
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3 votes

Is there a way to upscale without re-encoding?

To get from 1080p to 4K you're going to need to re-encode, but container won't matter (much), so 16bit png is overkill just for the sake of 4K. H.264 works fine. But before you spend the time to ...
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3 votes

Simulating 1080p pan shot by cropping stationary 4K fisheye footage?

Yes, you can do this successfully. I did it with an overhead 4K action camera with a fixed fisheye lens (YouTube video here). You'll want to remove the distortion in software to "square it up". Then ...
2 votes

Does 4K impact quality when filming in low light? (other parameters being equal)

Short answer: no, 4K down-scaled to 1080p is not necessarily going to give you a better result than filming with a FullHD camera. The SONY A7S is the hands-down best low-light video camera for less ...
2 votes
Accepted

Does it make sense to upgrade my set up to 4K from a (Canon) 70D set up?

It all boils down to "Do you need it" If you are shooting corp promos and your clients keep asking or are insisting on 4K then Yes you can look into it as you can justify the purchase as the work is ...
2 votes

How to capture 4K screens?

As you know there are two solutions, one using your CPU, the other a dedicated GPU. CPU Solution As of today, the CPU solution exit for 4K content, at 60 fps, using x265 or x264 codec. x264 is ...
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2 votes

Do Film Makers Want 4k?

We shot one of the first indie HD films back in the day when the prosumer HD cameras first came out. Because we were one of the first feature films to shoot in HD we secured a national theatrical ...
2 votes

Why do cinema cameras cost too much?

In addition to the points above, keep in mind that cinema cameras also have a host of features not found in cell phones and lower-end cameras, such as removable lenses, better autofocus, better bodies ...
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2 votes
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Tips to start making a little production

Story Your film needs drama. That is normally created by conflict or tension. Keep the story simple. It is better for your first film to be too simple than too ambitious. But it must have drama. Shot ...
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