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6

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 generates a lot of questions on forums everywhere). Try adding -c:v libx264 -crf 20 -preset slow to the command. -c:v libx264 tells it to use the libx264 ...


5

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.) It's simple math: when you have a straight line and you make it twice as long, the new length is 2x the original length. When you have a rectangular area ...


5

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 a 1080p time line. Why it may look better is because most sensors these days use chroma subsampling. On most consumer 1080p video camera products, the camera ...


5

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 of Field. Often this is a requirement at night, since cutting off most of your light is generally a bad idea. When looking at any camera, see what lenses are ...


4

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 purchase a CPU that's 10% or 30% faster than "normal" and you might then have some understanding of how much more expensive it is to offer 10x or 30x the performance ...


4

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 hardware for cameras capable of recording RAW footage is more expensive. Also, it hasn't been around for as long and as with every new technology, prices start ...


4

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 5.2 supports upto 9437184 luma samples per frame, which is the number of luma samples needed for a frame of size 4096x2304. So, there may be encoders that can (be ...


3

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 that freshly imported clip onto your freshly created sequence in your freshly created project, it should work as you expect. And if you right click on the clip, ...


3

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 will scale up text and icons on a HiDPI display. Vegas does not do this. So, the value should be changed from true to false. The hack tutorial alongwith link to ...


3

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 any quality loss. If you shoot a talking head in 4k but deliver in 720p, you can get a wide, medium, and closeup from the same shot. In my experience clients ...


3

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 because they don't even know that they would want to change them, let alone how that would happen. In my opinion you're wasting your time because your client ...


3

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 embededded in OBS in fact, and x264/x265 are known for being the fastest implementation of the standard H264/H265. But, you need a powerful CPU, of course, and then ...


3

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 -acodec copy D:\%%~na.mp4


2

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 that may be weather-resistant or weatherproof. They also have larger sensors which cost more, and the specs on the sensors are probably better than in low-end ...


2

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 level was 5.1 and 5.2 was introduced later. If needed new levels can be introduced as long there's the hardware to support it. For eg. the Nvidia NVEC supports ...


2

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 going to pay for it in the end. If it is just an odd job here and there that they want 4K then hire one as it will be much cheaper at £££/$$$ for a day or two ...


2

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 release. If I was shooting a feature film today, I would do it in 4K. Because at some point in the near future theaters, NetFlix, Cable Networks, etc. will be ...


1

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 -qp 0". This will probably result in failing your 3rd requirement (compatibility), but since it's lossless, you can transcode later onto cheap spinning disks. ...


1

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 products is sub 10€, so even if the Red or Alexa use a 100€ fpga, that's not the point. Media storage is also not the point, since all vendors use standard ...


1

I have a Blackmagic Design DeckLink card which, with bundled software, provides live keying. I bought that card before they sold a DeckLink 4K cards. But because they come withe the same bundled software and make the same live-keying claims, I would check that this version first: https://www.blackmagicdesign.com/products/decklink/techspecs/W-DLK-04 You ...


1

Based on this illustration, you are able to compare the sensor sizes of red cameras with film formats like 16mm, 35mm or 70mm imax and so on.


1

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 than $34,000. (The Panasonic Varicam S35 and the Alexa can shoot better images, albeit at much higher costs). Here's a surf video shot entirely by moonlight, ...


1

As I understand it, ffmpeg creates a raw image buffer with the input files it is given, then applies effects such as scaling and then encodes. So if you use ffmpeg to do the scaling and encoding to a 4:4:4 codec it should do what you want: ffmpeg -i "my_gh4_422_4k.mov" -vf scale=1920:1080 -c:v prores -profile:v 4 -c:a copy "my_prores_444_1080.mov" It ...



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