#rendering video linux

[winuxguy-blog]

Rendering videos in Linux

One thing I have found difficult with my transition to Linux, has been video editing. Kdenlive is easy to use, however once I get to the rendering process all bets are off.

Too often I run into issues with my HD videos having bars on the side/top, poor quality just so I can get a respectable file size...

Well I think I've found out how to properly render a video in Linux so I have both quality and size!

You are going to need two programs to do this (or one if file size doesn't matter).

Kdenlive and Arista Transcoder. You should be able to find both of these programs in the software manager. Arista came pre-installed with Pinguy!

I have done this with a video that is 1280 x 720, and on a 24" HD monitor. Results might be different depending on your monitor as non-HD monitors may still show large bars on the top and bottom.

Working in Kdenlive:

Step One - Before adding any videos to the project tree, hit the 'New' button at the top left.

In the profile drop down menu, select the option that best suits your video. In my case my video is 720p, so I went with the "HD 720p 30 fps" option.

Now add your video like usual to the project tree.

Step Two - Edit as you normally would.

Step Three - Now time to render your video.

I use the 'H.264' option, however I believe you can get away with using the MPEG-4 option as well since they both will be .mp4 files.

When it comes to choosing which option to use with H.264, this is up to you. I find using at least 6000k yields good results. Best to try rendering the same video a few times with the different choices to see what works best for you, then remember that for future uses.

Single or double pass?

Again, you can get away with a single pass but personally I use the '2 pass' option.

Please note that using 2 pass will result in slightly longer rendering times, as well the higher the 'k' you use the larger the file.

Now that your file has been rendered, you should be able to play it without any bars on the side, top or bottom (again depending on your monitor). It should be full screen or at least nearly full screen!

My rendered file size is 117 MB. In my opinion this is too large for a video that is only 1m:40s long.

I like to have the smallest file size possible without losing too much video quality. Having a 60GB monthly cap (going up to 80GB in a couple of months!) I don't want large uploads.

Despite having a 1TB + 500GB + 60GB hard drive(s), I also don't want large files wasting space on my hard drive(s).

If you want a smaller file size, follow the next step. If size doesn't matter then you should be done!

Working with Arista Transcoder:

Step Four - Select your source (video file).

For device, make sure 'Computer' is selected.

For the preset, I use 'Live Input'.

Hit the 'Add to Queue' button at the top left then name/save it wherever you'd like.

Now your file size should be considerably smaller without much loss in video quality!

My video went from 117 MB down to 24 MB.

You also have the option to select WebM if your uploading to Youtube. This is ideal since Youtube renders most videos now in the HTML5 (WebM) format, which means they won't have to re-render the file.

To render in WebM format do the following:

Select your source (video file).

For device select 'Web Browser'.

Make sure the preset is set for 'WebM'.

Hit the 'Add to Queue' button at the top left then name/save it wherever you'd like.

The WebM file will be slightly larger then your mp4 (live input) file, however not by much. My WebM file is 32 MB, only an 8MB difference. Like I said above, since YouTube is switching to HTML5, WebM files are ideal for uploading to that site.

Hopefully this works for you, as I was going mad trying to get rid of those bars and get a good quality video with a small file size!

[winuxguy-blog]

Windows v. Linux - Video rendering (time, size, quality)

I have been using Sony Vegas for a couple of years now with Windows 7. I can't say I have any complaints with it.

Since joining the Linux world, I have obviously made the switch to kdenlive. Seems like the more popular and easy to use video editing program.

I did a little comparison with Windows & Linux.

I rendered the same file which was 312 MB.

With Sony Vegas in Windows, the rendered file went down to 70 MB and took a little over 17 minutes to render. While rendering I couldn't do anything else as it was far too slow.

In Linux, my Kdenlive rendered file was 117 MB and took a little over 12 minutes. While rendering I was surfing the internet as if I wasn't doing anything else.

After the rendering was complete I used a program called Arista Transcoder which then rendered the file down to 24 MB (with no noticeable video quality loss). This process took just under 2 minutes.

Who wins?

Quality - Draw. You'd have to spend too much time looking hard at each video to see a difference in quality between the one rendered with Sony Vegas and the one rendered with Kdenlive & Arista Transcoder.

Time to render - Linux. Although with Linux it took two steps, it was still about 2-3 minutes faster then with Windows.

Plus while rendering in Linux you can check your email or do whatever else you like on the internet without any noticeable performance decreases! 

I suppose the plus with Windows is I had 17 minutes to clean or do whatever else I had to get done around the house, but for the most part the computer was far too slow during the rendering process to even surf the internet.

I should note this might be different for everyone. My PC is an AMD triple core processor with 8GB RAM.

File Size - Linux. If you don't use Arista Transcoder, then Windows would win, but Arista Transcoder shrinks the file size considerably with little to no noticeable loss in quality.