Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I see that there's a -threads <count> command line option in ffmpeg. What is the default value of this option?

share|improve this question

3 Answers 3

up vote 4 down vote accepted

it depends on codec used and your CPU core count. For example libx264 for encoding into H.264 use 1 thread per CPU core.

share|improve this answer
    
Thanks. Do you have a reference to the defaults for some standard codecs supported by ffmpeg? –  scompt.com Jun 22 '10 at 9:26
1  
Don't rely on it. My ffmpeg 0.7.8 on Linux uses 1 thread by default no matter what. –  Barafu Albino Dec 22 '11 at 19:30

assuming you have threading enabled, it assigned 1.5x number of cores.

share|improve this answer

As of 2014, it uses an optimal number.

You can verify this on a multi-core computer by examining CPU load (Linux: top, Windows: task manager) with different options to ffmpeg:

  • -threads 0 (optimal);

  • -threads 1 (single-threaded);

  • -threads 2 (2 threads for e.g. an Intel Core 2 Duo);

  • none (the default, also optimal).

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.