Batch rendering 20+ videos in succession takes forever

Help/How To
1

Hy there,
today I cut roughly 20-30 video clips and paused the immediate rendering to have them all render in succession over night…
Now whilst I cut and rendered single videos before (which took about 4-5 mins each) the rendering of the first video (about 1 min long) of that batch takes approx. 8 hours alone with all the other videos still in queue!

  • My clips are all 60fps 4k and between 15 secondes to 3 minutes each.
  • I am using Shotcut Verion 20.09.13
  • on a Dell mobile workstation with a Core i7 @ 2.7 Ghz (not ideal, i know), 16 GB RAM and an NVIDA Quadro M2000m running on Win10 x64.

I have three quesions:
1: why does the rendering of one single file (about 30 seconds video) take so much longer when there are about 20 videos queued up?
2: if i close the Shotcut project, will all the export/render tasks also be saved and restored upon restart?
3: if so, will all the cuts I made be still there so I can continue rendering
Alternatively: can I read out the information of the rendering queue, i.e. video 1: in @15 sec, out @55?

I really appreciate your help!

Best regards, KaTo

2
  1. It does not normally. I suspect your system was running very low on memory and swapping a lot.
  2. no
  3. The playlist is saved if you used that; that is the only way trimmed shots are saved.
3

Thank you for the quick response.
Actually memory was at max 70% - CPU on the other hand was/is at 100% nonstop!

I was wondering if some GPU setting causes CPU to be maxed out? Even regular playback pushes CPU usage towards 90%.

4

I have no other explanation, and you need to troubleshoot the conditions that trigger the problem because I did not reproduce it:

image
image862×778 247 KB

The GPU is only used in export when you turn on the hardware encoder. You can read more about CPU and GPU in the FAQ.

5

Alright. Have it rendering @work throughout the night and will see what the progress is tomorrow morning. Cutting the videos took a fair amount of today - but if until tomorrow morning only 4-5 clips have rendered I will terminate the process and try to get to the bottom of this.

Thank you for your help, really appreciate it!

6

Hy Dan,

incredible - about 20 hours after initially starting the rendering process within the job list there are 2 clips rendered (total clip duration < 2 minutes) and the third one at 44 %. I have screenshots attached with the job list and CPU usage within the past 20 hours.

Job-list
Job-list326×965 65.3 KB

I have no idea why rendering through the job list clogges up CPU so much whilst rendering a single clip takes about 3-4 minutes at max.

CPU has been maxed out for the last 20 hours - RAM on the other hand hardly was above 50 %.

Kind of frustrating, that I will have to terminate a days work (for trimming) in order to start any other task at my workstation.

Any help is appreciated.

7

2020-11-10_05-14-09

  1. From this project file, what is the Video Mode? Click on Output, then Properties. Resolution - exact FPS.
  2. What are the properties of the 4K footage (look at FPS). Click on the source clip, then Properties. What is the exact FPS shown on Shotcut?
  3. Did you select an export preset? If so, which one?
  4. In the export panel, did you enter Advanced? If so, did you change anything?
  5. If you did change settings in Advanced, what did you change?
  6. Are you exporting to a Hard Disk Drive (HDD), Solid State Drive (SSD), or NVME?
8

Hello Hudson555x,

  1. framerate of the project is at 59.940060 fps, the Codec ist H.264
  2. the source Clip also has 59,940060 -> Video was recorded on a GH5 and was shot at 4k 60fps also H.264
  3. no preset was chosen - although I just noticed that the codec in the codec ribbon is at libx264 - if that might be an issue
  4. initially haven’t messed with the settings in the advanced tab, hardware encoder was initially deactivated - although I switched it on after the post of @shotcut - the process had already been running for several hours by then
  5. see 4
  6. the data is read from and exported to a SSM ( SK Hynix SC300 512GB)

I really appreciate your help!

9

Does the project use any slow filters like Remove Noise: Wavelet?

10

Nothing, had just been used for trimming/clipping

11

This topic was automatically closed after 90 days. New replies are no longer allowed.