Home/ Questions/Q 8091097
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-05T19:57:07+00:00

I’m working on an algorithm which needs very fast random access to video frames

  • 0

I’m working on an algorithm which needs very fast random access to video frames in a possibly long video (minimum 30 minutes). I am currently using OpenCV’s VideoCapture to read my video, but the seeking functionality is either broken or very slow. The best I found until now is using the MJPEG codec inside a MKV container, but it’s not fast enough.

I can chose any video format or even create a new one. The storage space is not a problem (to some extents of course). The only requirement is to get the fastest possible seeking time to any location in the video. Ideally, I would like to be able to access to multiple frames simultaneously, taking advantages of my quad-core CPU.

I know that relational databases are very good to store large volumes of data, they allows simultaneous read accesses and they’re very fast when using indexes.

Is SQLite a good fit for my specific needs ? I plan to store each video frame compressed in JPEG, and use an index on the frame number to access them quickly.

EDIT : for me a frame is just an image, not the entire video. A 30mn video @ 25 fps contains 30*60*25=45000 frames, and I want to be able to quickly get one of them using its number.

EDIT : For those who could be interested, I finally implemented a custom video container saving each frame in fixed-sized blocks (consequently, the position of any frame can be directly computed !). The images are compressed with the turbojpeg library and file accesses are multi-threaded (to be NCQ-friendly). The bottleneck is not the HDD anymore and I finally obtained much better perfs 🙂

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I don’t think using SQLite (or any other dabatase engine) is a good solution for your problem. A database is not a filesystem.

    If what you need is very fast random access, then stick to the filesystem, it was designed for this kind of usage, and optimized with this in mind. As per your comment, you say a 5h video would require 450k files, well, that’s not a problem in my opinion. Certainly, directory listing will be a bit long, but you will get the absolute fastest possible random access. And it will certainly be faster than SQLite because you’re one level of abstraction under.

    And if you’re really worried about directory listing times, you just have to organize your folder structure like a tree. That will get you longer paths, but fast listing.

    • 0