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what are your prefered proxy files?

kalimerox
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what are your prefered proxy files?

Wed Jul 16, 2014 2:00 pm
Hi there,

I m always using proxy files to edit cause it s going too slow otherwise (editing directly .mts files from a sony cam)

but I still havent figured out a proxy files that still look good and i can still see if a shot is out of focus etc..

I tried with this:
-f mpegts -acodec libmp3lame -ac 2 -ab 128k -ar 48000 -vcodec mpeg2video -g 5 -deinterlace -s 960x540 -vb 400k

but it s very pixelated when i see it on a normal size screen and not really useful. Any ideas? Is it maybe the codec itself that is not very good for that or should i alter the bitrate etc? Optimum would be a sharp picture and fast response at the same time..

Thanks!!! :)
kalimerox
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anyone? do you all use the preset for proxy files and it works fine? maybe then theres something wrong with my machine.. ;(
User avatar TheDiveO
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At 540p and with 0.4Mbps ... do you really expect to be able to do focus control with these proxy clip parameters? I would expect focus control to be part of your first step when setting in and out points on the source clips to get the individual takes from the raw shots. Maybe you can do this on raw footage or proxy footage at 720p resolution and 6 to 8 Mbps. Later, when applying effects, switch to lower resolution proxies. If it is important to you, invest in a decently powerful machine ... but the upcoming Moveit support may make high end hardware to become of much less importance. On a sidenote I use a core i7 octocore for working with 1080p 25fps 25mbps and 2.7k 25fps 42mbps footage ... and that still sucks especially when I have to slap on four and more effects juat for Protune grading, so I'm also using proxies...


TheDiveO on YouTube: diving videos and aerial (quadcopter) videos, all made with Kdenlive.
TheDiveO Blog: know-how about Protune-grading in Kdenlive, GoPro HD Hero 3, DJI Phantom Quadcopter, full face mask diving, and some more...
kalimerox
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Thanks for your comment TheDiveO,

no, I dont expect really to control focus with these parameters, therefore my question ;)

what paras do you use? I m not very good at the command line with ffmpeg so I d be happy you post your proxy values..

I m on an i5 with 12gig ram but yes it s fine editing when i have one or two tracks, with more no chance..
problem is that even with these parameters
-f mpegts -acodec libmp3lame -ac 2 -ab 128k -ar 48000 -vcodec mpeg2video -g 5 -deinterlace -s 1920x1080 -vb 3000k

I get a grainy bad image i dont really like working with ;(

so any suggestions? Thanks

edit: sorry, now i get your suggestion: i see the 3000k might be still not enough, I ll try pushing it up and will let you know..


and how do you change the proxy quality within a session? when i go to project settings changing the proxy presets it sais: new proxies are gonna be made, but nothing happens but a big mess with my files.. ;(
User avatar TheDiveO
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Maybe Movit support may satisfy your requirements ... but it will be some time till Movit support in Kdenlive will be stable.

So in the meantime you may want to reconsider your workflow to get more bang from your system? Your system should be more than sufficient to play back raw footage at full 1080p resolution and higher bitrates, so use this for checking focus while sifting through your clips. During this phase switch off proxies so you can check focus and set in and out points.

Next, enable proxies and throw the selected clip sections onto the timeline. Don't apply effects yet except maybe some geometric transformations for compositing frames from more than a single clip. Walk your way through the whole project so you get the raw scene cuts right. When done here, freeze.

Only now freeze your scenes, enable proxies, and start working your way further through post, grading the frozen scenes. Apply other effects as necessary. Of course, at this stage you will need to work with proxies and you may even need to work with really low bitrate proxies, depending on the number of effects per clip. If you need temporarily better quality, switch off the proxy for the clip you are working on, then switch it on again.

This process served me well so far.


TheDiveO on YouTube: diving videos and aerial (quadcopter) videos, all made with Kdenlive.
TheDiveO Blog: know-how about Protune-grading in Kdenlive, GoPro HD Hero 3, DJI Phantom Quadcopter, full face mask diving, and some more...
kalimerox
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Thanks! Yes that s a good workflow for the resources ..!

I ll try that and let you know how far i can go. Didnt completely understand the movit thing, but is it that it uses the gpu to have more "horsepower" to render and playback? Looking forward to it then :)
User avatar TheDiveO
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Yes, movit is about offloading frame rendering to the GPU. However, we still have to see to what extent this works and how much of a bottleneck the CPU-GPU interface then will become.


TheDiveO on YouTube: diving videos and aerial (quadcopter) videos, all made with Kdenlive.
TheDiveO Blog: know-how about Protune-grading in Kdenlive, GoPro HD Hero 3, DJI Phantom Quadcopter, full face mask diving, and some more...
Pianandrill
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You might have pixelated image because of mpeg2 codec. Try using h.264. It works well for me.
My proxy:
-f mp4 -acodec ac3 -ab 128k -ar 48000 -vcodec libx264 -g 5 -vf yadif=1:-1:0 -threads 4 -preset veryfast

I have laptop with core i5 so its not video editing monster :) As a source I use AVCHD 1080i

This preset recodes it to h264 1080p and deinterlace it (-vf yadif=1:-1:0) with 50fps - this is also called yadif2x as it makes "copy" of every secound interlaced frame.
If You need to You can add -s 1280x720 option to lower res a bit.

Problem is i cant produce rendering profile with yadif2x. Using deinterlace=1 and deinterlace_method=yadif makes video yadif not yadif2x and drops framerate to 25fps. It looks choppy than. If anyone knows some commands to force mlt to use yadif2x please share.
For now I just "precode" my videos with avconv to get rid of interlace the way i want (yadif2x) and than use those 1080p@50 videos in my projects. What i need to is one time decode solution, so i could import my raw 1080i@50 AVCHD to project and recive 1080p@50
kalimerox
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@Piandandrill thanks, I ll try the h264 codec on my next project, yes it should render some better image quality .. thanks again for your helpful advices everyone

 
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