What exactly does it mean, if someone renders a video?

[MatejAustria]

Many people recommend i7 CPUs for video production (e.g. YouTube), because it can take 1h to render a short video. I was always wondering what the PCs actually do such a long time, because it is not possible that it takes so long if you just use some filters and add an intro.

[c3p0_]

Render means converting it to a diffrent video codec. If you just add an intro and filters you will get 5 gigabytes of video that takes forever to upload. After the render you should have 500mb to 700mb per 15 minutes in 1080p which is easier to upload.

 

Better cpu = more threads means more to handle the converting. So its faster done. 

[OfficialJsP]

it all depends on the render settings such as what FPS the video is rendering at and what resolution and effects and how long the video is and what he/she said^

[MatejAustria]

Render means converting it to a diffrent video codec. If you just add an intro and filters you will get 5 gigabytes of video that takes forever to upload. After the render you should have 500mb to 700mb per 15 minutes in 1080p which is easier to upload.

 

Better cpu = more threads means more to handle the converting. So its faster done. 

why do people even film in formats they do not like to use?

[c3p0_]

why do people even film in formats they do not like to use?

 

Why. Because recording and heavy encoding at the same time lowers your fps. No matter what magical recording software you use.

[ForsakenLive]

why do people even film in formats they do not like to use?

because you can't. Regular used formats are already compressed and rendered, thing a recording device can't do most of the times, you get your raw footage from the camera that is extremely heavy and difficult to handle for a system, it has the highest quality and you can edit on it, then it gets sampled and compressed into different formats, resolutions, etc. You will not get a MP4 file from a DSLR.

[.spider.]

Rendering is super fast and mostly limited by your HDD speed.

It's just reading the source video (and decoding) -> making changes -> writing new "raw" file

Even if these changes are done in 32bit color depth you can reach speeds up to 50fps in 1080p.

Some programs support to compress the "raw" output directly.

This is the part which takes so long if you are aiming for low bit per pixel ratios.

[evinta]

I built my current with this in mind. I render 1600x900 videos (short ones) under ten minutes each. Mostly under 5.

 

I do use lower end codacs as since they are played at church it doesn't need to be high quality however its nice to know that if im having to export the best i don't need to wait forever.

[omniomi]

why do people even film in formats they do not like to use?

 

People are over simplifying what it means to render when they say it's just file conversion. While it's true that you may have multiple video types or even just one that's different from your final desired format and the software needs to convert everything as it saves, rendering is more than that... If you have effects of any type the rendering process is calculating the effect and saving its results frame by frame. If you imagine a "simple" effect like colour correction when you go to render the video it will colour correct each frame as it saves the video. In a 29 FPS 10 minute video that's 17,400 frames that need to be colour corrected. Let's say it takes your machine .25 seconds to colour correct each frame, that's 72 minutes (over an hour) just on colour correction. It's CPU mostly although you can offload some rendering to your GPU as well. 

 

Things get even more complicated if you're working with 3D and/or any sort of lighting effects as it has to calculate reflections, shadows, and things of that nature. On my rig which has an i7-4770 and 32GB of RAM it took just shy of 8 minutes to render this single still image: http://i.imgur.com/YqfOp5V.png now imagine if it was some sort of video even one 29 FPS for 30 seconds would take forever to render... Actually 3D is the best way to illustrate what rendering is: this, http://i.imgur.com/Vir5glW.jpg is unrendered.. The rendering process is where all of the reflections, glow, and shadows come from. In simplest terms rendering is taking a bunch of parts and settings and creating a final product, not just conversion.

[.spider.]

 

 

Things get even more complicated if you're working with 3D or any sort of lighting effects as it has to calculate reflections, shadows, and things of that nature. On my rig which has an i7-4770 and 32GB of RAM it took just shy of 8 minutes to render this single still image: http://i.imgur.com/YqfOp5V.png now imagine if it was some sort of video even one 29 FPS for 30 seconds would take forever to render.

I don't think his question was about CGI

[omniomi]

I don't think his question was about CGI

 

Doesn't matter. Rendering 3D and video is essentially the same thing. Effects in Premier are CGI of a type and the rendering is the same basic principle... The machine is calculating the effect of the effect (hah) on the source frame by frame... With 3D CGI the software is calculating all of the polygons and lighting frame by frame. Same basic principle; Video rendering is not just file type conversion.. I also said "Things get even more complicated if ..." which makes it clear I was taking the explanation further than OP asked.

[.spider.]

Nah, rendering a video and rendering a CGI is a completely different thing. 

[omniomi]

Nah, rendering a video and rendering a CGI is a completely different thing. 

 

Fundamentally no. OP asked what rendering was, In 3D graphic and video rendering both have many things in common and obviously some things that are different but the definition of rendering remains the same. Video rendering is generating each frame not just converting the file types, 3D rendering is generating each frame not just converting to a PNG.

 

Pop Premier or After Effects open and import an MPG and save it out as an MKV and time it.... then apply a filter to the entire clip,  doesn't mater which one, and save it again as an MKV... It will take longer... Why? It's rendering the effect on each frame which is fundamentally the same thing 3D software does. That effect is CGI. They might use different math and engines but both 3D rendering and video rendering are creating images from source data.

 

 http://en.wikipedia.org/wiki/Rendering_(computer_graphics)

[.spider.]

They might use different math and engines but both 3D rendering and video rendering are creating images from source data.

 

You say it yourself. 

Video rendering/editing is basically transforming and applying a LUT to the source video.

 

While CGI is a whole different level

http://en.wikipedia.org/wiki/Ray_tracing_%28graphics%29