Ffmpeg threads

This article ffmpeg threads how the FFmpeg threads command impacts performance, ffmpeg threads, 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.

Connect and share knowledge within a single location that is structured and easy to search. What is the default value of this option? Sometimes it's simply one thread per core. Sometimes it's more complex like:. You can verify this on a multi-core computer by examining CPU load Linux: top , Windows: task manager with different options to ffmpeg:.

Ffmpeg threads

It wasn't that long ago that reading, processing, and rendering the contents of a single image took a noticeable amount of time. 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. But where to move that split now? Basically the systems of today are entirely different beasts to the ones commonly on the market when FFmpeg was created. This is tremendous work that requires lots of rethinking about how the workload needs to be defined, scheduled, distributed, tracked, and merged back into a final output. Kudos to the team for being willing to take it on. FFmpeg is one of those "pinnacle of open source" infrastructure components that civilizations are built from. I assume 1 process with 2 threads takes up less space on the die than 2 processes, both single threaded. If this is true, a threaded solution will always have the edge on performance, even as everything scales ad infinitum. LtdJorge 3 months ago root parent next [—]. Hardware threads are not the same as software threads. Thanks Capt Obvious. LtdJorge 76 days ago root parent next [—]. I don't understand your comment then.

My conclusion: Specifying the number of threads is unnecessary for libx

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.

The libavcodec library now contains a native VVC Versatile Video Coding decoder, supporting a large subset of the codec's features. Further optimizations and support for more features are coming soon. Thanks to a major refactoring of the ffmpeg command-line tool, all the major components of the transcoding pipeline demuxers, decoders, filters, encodes, muxers now run in parallel. This should improve throughput and CPU utilization, decrease latency, and open the way to other exciting new features. Note that you should not expect significant performance improvements in cases where almost all computational time is spent in a single component typically video encoding. FFmpeg 6. Some of the highlights:. This release had been overdue for at least half a year, but due to constant activity in the repository, had to be delayed, and we were finally able to branch off the release recently, before some of the large changes scheduled for 7. Internally, we have had a number of changes too. This also led to a reduction in the the size of the compiled binary, which can be noticeable in small builds.

Ffmpeg threads

Connect and share knowledge within a single location that is structured and easy to search. What is the default value of this option? Sometimes it's simply one thread per core. Sometimes it's more complex like:. You can verify this on a multi-core computer by examining CPU load Linux: top , Windows: task manager with different options to ffmpeg:. So the default may still be optimal in the sense of "as good as this ffmpeg binary can get", but not optimal in the sense of "fully exploiting my leet CPU. Some of these answers are a bit old, and I'd just like to add that with my ffmpeg 4. In on Ubuntu I was playing with converting in a CentOS 6. Experiments with p movies netted the following:.

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If no chapter mapping is specified, then chapters are copied from the first input file with at least one chapter. I use ffmpeg all day every day, and only a fraction of the time do I actually make a video. It looks like they've run x in an unnatural mode to get an improvement here, because the default "constant ratefactor" and "psy-rd" always behaved like this. See [0] for a sample. I'm excited for this development. It could have been a memory issue too - it only had 1GB assigned to the VM. GPT has trouble understanding bit masks in single threaded code, let alone multiple threads. For output streams it is set by default to the number of input audio channels. Stream handling is independent of stream selection, with an exception for subtitles described below. I think it's normal. Related 2. While I believe that LLMs can be good tools for a variety of usecases, they have to be used in short bursts. This option controls the maximum duration of buffered frames in seconds. Isn't that delta partially based on the last keyframe? In on Ubuntu

Connect and share knowledge within a single location that is structured and easy to search. Please advise. Thanks, Mark.

Johan Bergquist August 13, at am. Realizing that the initial encode of p60 3 Mbps was unreasonably hard, I decided to test a number of files at a more leisurely p 4. It reads image sequences with imagemagick or ffmpeg, but in place repair is not its thing, no. It also has a lossless codec ffv1 where the entropy coder doesn't reset, so it truly can't be multithreaded. This can be abstracted into a custom component or hook. If device is any other string, it selects the first device with a name containing that string as a substring. When this tool is invoked, we stream the video of these browser interactions with FFmpeg by streaming the virtual display buffer the browser is using. Mainly used to simulate a capture device or live input stream e. To select the stream with index 2 from input file a. Packets of selected streams shall be conveyed from the input file and muxed within the output file. The time base is copied to the output encoder from the corresponding input demuxer. Andreas — thanks for your comment.