Lots of lost frames in movies, huge ITI and long loading time of conditions file

I have been trying to play videos in a fixation task using monkeylogic ver 2.2.21.

However, I am facing the following issues:
- I have 392 trials in my conditions file. But it is taking more than 15 minutes to load the whole conditions file in monkeylogic.
- My videos are 600 x 600 pixels in resolution and of ~80 mb in size. However, while playing in monkeylogic, I am getting lots of lost frames and the video also looks laggy.
- once conditions file is loaded and I run the task on ML, I am getting huge ITI (5-10 seconds!)

FYI, these issues were not there in the previous version of monkeylogic (v 2.2.20) that I had used.

Any help regarding this will be very much appreciated. If required, I can share my conditions file and other dependencies I am using with you for troubleshooting purposes.

Are you saying that each of your movie files is ~80 MB? What is their duration?

How many movies do you load in each condition? Are you playing them all in one trial?

What kind of storage device (e.g., HDD) are you using to keep the movies?

Nothing has changed from 2.2.18 regarding to the movie playback. If you ran the same task with the previous version, you would see exactly the same issues.

Hi Jaewon,

Thanks for the prompt reply and sorry for the late response. To answer your queries:

- My original movie files (.avi format) are of ~80 mb size each. However, I have tried to troubleshoot the long load-time and frame-loss issue by compressing their size to ~85 kb each. In both cases, they appear to be laggy (lost frames) and take huge time to load the conditions file and also give high ITI.

- Each movie file contains 80 frames which are rendered at 59.99 frames per second and are played on a elo touch screen monitor capable of displaying at 60 Hz.

- In each condition file, I am currently loading 784 videos. Each row of my conditions file is a trial. Each trial plays 2 videos. I am NOT playing all of them in one trial.

- I am using an SSD to store all my videos.

I am attaching my conditions file for you to take a look.

Please download the package again. I changed some parameters to improve the loading time and the ITI. It may help with the playback issue a little bit, too, but basically you should try to reduce the load of your system.

You should compress your movies no matter what. If you play movies simultaneously without compression, your disk has to feed data at ~120 MB/s. Even if your disk is an SSD, it is too much.

From the compression ratio you said, it appears that your videos are not natural movies. Reduce the frame rate to usual 30 frames per seconds, if it is okay.

Do not include the movies that you will not play in the condition. That is the major reason of all your problems. Use the userloop function to dynamically create only necessary movies.
https://monkeylogic.nimh.nih.gov/docs_CreatingTask.html#Userloop