How many threads does ffmpeg

James

Apr 28, 2025

10 min read

How many instances of FFmpeg commands can I run in parallel? Ask Question. Sometimes it's more complex like: Wit. Stack Exchange network consists of 183 Q&A communities including Mountain Overflow, the largest, of trusted online society for developers to learn, share .h264_videotoolbox use videotoolbox an API to access hardware on macOS.10I was playing with converting in a CentOS 6.Meilleure réponse · 39Some of these answers are a bit old, and I'd just like to add that with my ffmpeg 4. edited Jun 8, 2023 at 18:48.There are three output files specified, and for the first two, no -map options are set, so ffmpeg will select streams for these two files automatically.mkv is a Matroska container file and accepts video, audio and subtitle streams, so ffmpeg will try to select one of each type. setlocal enabledelayedexpansion. So, I search ffmpeg multithreading and decide using all cpu cores for decoding.png Last modified 3 years ago Last modified on Oct 1, 2021, 11:08:06 .What that does is pass the -threads option to ffmpeg to make ffmpeg use more threads/cores to encode.4 A longer delay will sound like an open air concert in the mountains: aecho=0.ffmpeg -i test. Running ffmpeg with x265 output on Ubuntu, the first system with more than 4 cores/threads I used (Ryzen with 4C/8T) ffmpeg ran great but if you ran several copies of ffmpeg, or loaded the system down when ffmpeg was running, you'd get a ~1-5% or so failure rate, it'd segfault at . htop showed this; only one core was used, and I got 16 fps convers.

Limit the number of cores/threads

3 Same as above but with one more mountain: .How many threads does ffmpeg use by default? Please support me on Patreon: https://www.comRecommandé pour vous en fonction de ce qui est populaire • Avis

video

And here's an example of converting an MP4 video to a WebM video: ffmpeg-i input.png These are the input images before and after transposing: test.Intel Quick Sync Video support is available in FFmpeg 2.comFFmpeg cheat sheet · GitHubgist.

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ffmpeg threads如何配置-音视频开发中文网

libavutil is a library containing functions for simplifying programming, including random number generators, data structures, mathematics .FFmpeg Libraries for developers.avi -b:v 64k -bufsize 64k output.I'm using ffmpeg libx264 to encode a 720p screen captured from x11 in realtime with a fps of 30.Critiques : 2

ffmpeg: limiting to single CPU core when encoding h264

Message ID: 20220905122020. by default it uses (IIRC) 1. Viewed 13k times.auto：这是默认值，它根据CPU核心数自动选择线程数。. when I use -tune zerolatency paramenter, the average encode time per-frame can be as large as 12ms with profile baseline. That is quite strange because normally whenever i convert something (i usualli convert anything to h265 to save disk space, as I'm doing rn) the cpu usage spikes to 100% and stays until the end.ffmpeg threads如何配置.4 If delay is very short, then it sounds like a (metallic) robot playing music: aecho=0.

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A lookahead thread — as its name suggests — looks at the incoming frames before they are transcoded, this is important for all sorts of stuff: Ratecontrol decisions, I-/P-/B-frame placement, AQ, etc.streaminglearningcenter.Will it be faster to process those videos one after another using -threads equal to number of CPU cores, or process multiple videos in the same time each being . However, measuring the same call in FFmpeg shows strange behaviour: (these are the times taken for each call to avcodec_send_packet () in milliseconds, when decoding a 4K 25fps VP9 . This release is not backwards compatible, removing APIs .comHow to utilize all cores on high-end CPUs using ffmpegsuperuser.threads configuration in php-ffmpeg ), the running process is .Please, also observe that this limit depends on the number of CPUs/Cores/Threads the machine has, for example, if the machine has 8 CPUs, CPULimit -l valid values will range from 0 to 800 (0 being useless, of course, and 800 meaning not limiting the process at all as 800% means all the machine processing capacity). libx264 is the default encoder which does not use any specific hardware this . x265 creates one or more thread pools per encoder, one pool per NUMA node (typically a CPU socket).Ffmpeg CPU usage. I have a high-end HPE ProLiant DL325 G10 server with an AMD EPYC 7401P 24-core/48-thread CPU, 128GB DDR4 . So if you have 8 threads, setting to -threads 6 would be great.setting -threads 6 for the mpeg4 encoding and it only improved by 2x the overall run time.mkv -c:v av1_amf output.

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How to utilize all cores on high-end CPUs using ffmpeg

Today i launched a command but the cpu usage is only 50 to 60 %.png -vf split[a][b];[b]transpose[b];[a][b]blend=all_mode=harmonic,pseudocolor=preset=turbo -y harmonic. int soundProcess(string infn, string outfn) {. an Intel Core 2 Duo); none (the . Today I noticed that ffmpeg is not using 100% cpu as always.

output_url: This is the output file.

How many threads does ffmpeg use by default?

You can also use libx264's native threads . 例如，使用 -threads 4 将使用4个线程。. There are two possible methods for transcoding: hardware decoding and hardware encoding, or software decoding and hardware encoding. Sometimes it's simply one thread per core. To optimize the process and take advantage of your hardware by rendering multiple files at once, you can use the start command in Windows to run multiple instances of the ffmpeg command concurrently.5 VM (Ryzen 1700 8c/16t - vm assigned 12 of 16 cores). By default x265 allocates one thread per (hyperthreaded) CPU core on each NUMA node.51it depends on codec used, ffmpeg version and your CPU core count. Configure FFmpeg with “--enable –libmfx –enable-nonfree”, build, and install. Set the video bitrate of the output file to 64 kbit/s: ffmpeg -i input.Modified 5 years ago.15In 2015 on Ubuntu 14.The most noteworthy changes for most users are a native VVC decoder (currently experimental, until more fuzzing is done), IAMF support, or a multi-threaded ffmpeg CLI tool.As of 2014, it uses an optimal number.0：表示禁止 . I tired running 8 . FFmpeg的线程数可以通过设置 -threads 参数来配置。. If you're using GPU encoding, then the number of threads doesn't help you. 该参数的值可以是以下三种类型之一：. --pools specifies the number of pools and the number of threads per pool the encoder will allocate.

My question: Even though I am passing in -threads 0 to the ffmpeg command (actually setting ffmpeg.

FFmpeg Filters Documentation

FFmpeg list all codecs, encoders, decoders and formats .On Tue, 19 Aug 2014 01:09:44 -0700 J Decker wrote: > On Mon, Aug 18, 2014 at 2:30 PM, wm4 wrote: > > > All functions that are specific to a certain context (like > > AVCodecContext) are by default not thread-safe.comRecommandé pour vous en fonction de ce qui est populaire • Avis

FFmpeg Threads Command: How it Affects Quality and Performance

I would leave this value on its default setting unless you're experiencing performance issues.

To optimize the process and take advantage of your hardware by rendering multiple files at once, you can use the start command in Windows to run multiple .gif -c:v libx264 output.I believe this message indicates how many bytes of the input file ffmpeg is trying to read at a time.avi -r 24 output. Development is active so anyone needing latest updates and fixes should check the git repository tip.数字：指定使用多少线程来运行FFmpeg。.I will note one use for frame-threads=1 though -- stability. Recommended that you set your number based on the amount of available threads minus 1, or 2.webm To convert faster, with multi-core processors, I've read it is recommended to use one less thread than you have of real cores.ffmpeg showing Thread message queue blocking error while .avi -c:v libvpx-vp9 -lossless 1 output. Thank you for helping. Modified 11 months ago. Force the frame rate of the output file to 24 fps: ffmpeg -i input. Modified 11 years ago. Joined: Fri May 08, 2020 5:18 pm. Of course using > > different contexts at the same time from different threads should be > > .

Working with ffmpeg on Multi-Core Systems

asked May 11, 2020 at 6:32.

HWAccelIntro

7assuming you have threading enabled, it assigned 1. FFMpeg has an option -threads.From profiling it, it appears that the one major bottleneck during decoding is the avcodec_send_packet() function, which can take up to 50ms per call.The most basic use of FFmpeg is to convert media files from one format to another.8 and newer for those who prefer a stable release. Use DX9 hardware decoder. NOTE: I must get std out and err to check for failures. asked Jan 3, 2019 at 10:03. output_file_options: These are options that apply to the output file(s), such as codecs, filters, etc.-filter_threads nb_threads (global) Defines how many threads are used to process a filter pipeline.UseShellExecute = false;

How many threads does ffmpeg use by default?

You can specify multiple input files.4 CPU i7-7500U.

ffmpeg Documentation

10-6, it used 1 core on a 4 core system.

FFmpeg itself is not multithreading safe in the sense that you shouldn't call av_read_frame or avcodec_decode_audio4 on the same context from different threads . However, if I encode 6 segments at a time on 6 different cores, I think I can get closer to 6x speedup. Here's an example of converting an MP3 file to an OGG file: ffmpeg-i input.com/roelvandepaarWith thanks & praise .News April 5th, 2024, FFmpeg 7. You can always perform a test.FFmpeg is using more threads than I expect when using .CD to the same working directory and ran the cmd (bin/ffmpeg) and pasted the argument. Hardware Decode and Hardware Encode. Viewed 16k times.0 Dijkstra A new major release, FFmpeg 7.For significantly more encoding time you can have an insignificant quality improvement and almost no file size difference.To add to this, you can use the -threads parameter to configure how many threads FFmpeg will use for decoding (by specifying it before the input) and encoding (by specifying it before the output) — you can also use the threads option to configure the thread count for any filter that supports multiple threads. Melt has its own option to use threads, and that one doesn't appear to be set anywhere by kdenlive .

ffmpeg

ffmpeg(1) — Arch manual pages

ffmpeg -i input.While ffmpeg has multithreading capability, getting the best performance on multi-core systems calls for something more than just playing with the -threads option.ffmpeg - thread_queue_sizeAfficher plus de résultats1FFmpeg Threads Command: How it Affects Quality and .

FFMpeg Encoding and Core Usage

by authorleon » Thu May 28, 2020 1:11 pm. Asked 1 year, 11 months ago. What is the neglect value of this option? Stack Markt Network. Experiments with 480p movies netted the followin.com20+ FFmpeg Commands For Beginners - OSTechNixostechnix.

ffmpeg: which functions are multithreading safe?

comFFMpeg How to use multithreading? - Stack Overflowstackoverflow. Asked 11 years, 3 months ago.0 Dijkstra, is now available for download. env: Ubuntu 14. If you're using CPU encoding, that will help your encoding speed.I see that there's a -threads command line option in ffmpeg.To add to this, you can use the -threads parameter to configure how many threads FFmpeg will use for decoding (by specifying it before the input) and encoding (by . ffmpeg -hwaccel dxva2 -hwaccel_output_format dxva2_vld -i input.Convert an input media file to a different format, by re-encoding media streams: ffmpeg -i input. It was able to complete.5x threads as you have . string aa, aa2; aa = aa2 = DEAD; var app = new Process(); app.