Ffmpeg threads

It wasn't that long ago that reading, processing, and rendering the contents of a single image took ffmpeg threads noticeable amount of time, ffmpeg threads. But both hardware and software techniques have gotten significantly faster. What may have made sense many years ago lots of workers on a frame may not matter today when a single worker can process a frame or a group of frames more efficiently than the overhead of spinning up a bunch of workers to do the same task, ffmpeg threads. But where to move that split now?

Opened 10 years ago. Closed 10 years ago. Last modified 9 years ago. Summary of the bug: Ffmpeg ignores the -threads option with libx It is normal for libx to take up more CPU than libx This does not mean that libx is not using multithreading. With both builds Zeranoe and mine and both commands, i've got the same problem with -threads option: it uses both threads instead only one.

Ffmpeg threads

This article details how the FFmpeg threads command impacts performance, overall quality, and transient quality for live and VOD encoding. As we all have learned too many times, there are no simple questions when it comes to encoding. So hundreds of encodes and three days later, here are the questions I will answer. On a multiple-core computer, the threads command controls how many threads FFmpeg consumes. Note that this file is 60p. This varies depending upon the number of cores in your computer. I produced this file on my 8-core HP ZBook notebook and you see the threads value of For a simulated live capture operation, the value was Pretty much the way you would expect it to. In a simulated capture scenario, outputting p video 60 fps using the -re switch to read the incoming file in real time you get the following. I used this FFmpeg command for these tests. My assumption was that the threads setting would have minimum impact on quality.

If so, just let me ffmpeg threads at [email protected] or via a comment below. But doing an actual complex task with lots of nuance and semantics-to-be-understood outright?

Anything found on the command line which cannot be interpreted as an option is considered to be an output url. Selecting which streams from which inputs will go into which output is either done automatically or with the -map option see the Stream selection chapter. To refer to input files in options, you must use their indices 0-based. Similarly, streams within a file are referred to by their indices. Also see the Stream specifiers chapter. As a general rule, options are applied to the next specified file. Therefore, order is important, and you can have the same option on the command line multiple times.

Anything found on the command line which cannot be interpreted as an option is considered to be an output url. Selecting which streams from which inputs will go into which output is either done automatically or with the -map option see the Stream selection chapter. To refer to input files in options, you must use their indices 0-based. Similarly, streams within a file are referred to by their indices. Also see the Stream specifiers chapter. As a general rule, options are applied to the next specified file. Therefore, order is important, and you can have the same option on the command line multiple times. Each occurrence is then applied to the next input or output file. Exceptions from this rule are the global options e.

Ffmpeg threads

Originally published August 1, pm. While ffmpeg has multithreading capability, getting the best performance on multi-core systems calls for something more than just playing with the -threads option. The most common choice for this option is the default 0 that means letting ffmpeg figure out what to do. While the -threads argument rages on, I decided to do some basic testing. The laptop is running Windows 10 Pro with Ubuntu The ffmpeg version is 4. For the first test, I picked an hencoded GoPro video just under MB in size and play time of about 2m 42s. The task was to split this video into multiple files of second duration each. Thus, the first file will contain frames for s, the second file — s, and so on.

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See -discard option to disable streams individually. Ugh why? If in doubt use -framerate instead of the input option -r. Override detection of CPU count. Because if not, this seems like a great way for getting the fabled "one year of experience, twenty times". Do you have a reference to the defaults for some standard codecs supported by ffmpeg? Why on earth would you possibly think that? The overlay filter requires exactly two video inputs, but none are specified, so the first two available video streams are used, those of A. When used as an input option before -i , limit the duration of data read from the input file. Set the number of audio channels. Every such directive creates a new loopback decoder, indexed with successive integers starting at zero.

The libavcodec library now contains a native VVC Versatile Video Coding decoder, supporting a large subset of the codec's features.

Pad the output audio stream s. Andreas Backlund April 6, at am. Maybe it was a surprise for you, but I was familiar with the pre-AlphaGo state of the art, and it was always clear it's just a technical problem. Rewrite it in Rust. References an Audio Element used in this Mix Presentation to generate the final output audio signal for playback. Furthermore, the audio stream is MP3-encoded so you need to enable LAME support by passing --enable-libmp3lame to configure. Demixing information used to reconstruct a scalable channel audio representation. Example Implementations: 1. Of course the outer loops will themselves be automated. FFmpeg is one of those "pinnacle of open source" infrastructure components that civilizations are built from. I use dd for that. Specifies the layouts for this sub-mix on which the loudness information was measured. I had to stop drinking my decaf for fear of spitting it all over my computer I was laughing out loud so much! Similarly the first video stream in the second input is linked to the second overlay input of overlay.