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• Capturing actual video stream quality using FFmpeg and FFplay – smooth recording but stuttering stream

  3 décembre 2024, par Karlitos Bemowo

  I’m trying to analyze the quality of a video stream over a local network using FFmpeg. My goal is to capture the actual streamed video (with all artifacts, stuttering, or buffering) as experienced in real-time, rather than a reconstructed, smooth output. Currently, the recorded video is perfectly smooth, but the live stream played using ffplay exhibits noticeable stuttering. Additionally, while the duration of the recording matches the original video, the live stream lasts longer, likely due to buffering caused by network instability.

  


  Here are the commands I’m using :
Sender :
ffmpeg -re -i file.mp4 -c:v libx265 -preset veryfast -f mpegts udp ://192.168.1.26:1234
Receiver :
ffmpeg -i udp ://192.168.1.10:1234 -c copy received_fhd.mp4 -fflags nobuffer

  


  The recorded file received_fhd.mp4 plays back perfectly, with no stuttering or frame drops, even though the network stream has visible issues when viewed in real-time with ffplay.The recorded file has the same duration as the original video (fhd.mp4), while the real-time stream playback with ffplay takes longer, suggesting delays caused by buffering or network issues. Same issue with with other codes for example vp9.

  


  GOAL : I want to capture the actual streamed video as experienced in real-time, with all stuttering, buffering, and artifacts included. This would allow me to analyze the network's impact on the video quality effectively.

  


  Questions :

  


  

  1. How can I modify my commands to record the video stream exactly as it is experienced in real-time, including any network-induced issues ?

  


  2. Is there a way to configure FFmpeg to behave more like ffplay in terms of handling and recording the stream ?

  


  


  Any guidance or alternative approaches would be greatly appreciated. Thank you !

  


  Experimented with different codecs (e.g., H.265, VP9) and output formats. Older codes has no delay in tranmission so I didn't notice the issue at frist.

  


  Explored various ffmpeg options like -fflags nobuffer and -c copy (as documentation says " For example, -codec copy or -codec : copy would copy all the streams without reencoding."), but it still doesn’t replicate the actual stream behavior.

  


• Nomenclature #4519 (Nouveau) : Renommage de terminologie (blacklist / whitelist)

  13 juillet 2020

  En lisant la compilation [PHP Annotated – June 2020](https://blog.jetbrains.com/phpstorm/2020/06/php-annotated-june-2020/) on tombe sur ce point :

  [[RFC] Change terminology to ExcludeList](https://wiki.php.net/rfc/change-terminology-to-excludelist) — The topic of renaming offensive terms has not been overlooked by the PHP world either. There have been [heated discussions](https://externals.io/message/110515) in the Internals.
  In the PHP core, the change affects only one thing : the configuration directive `opcache.blacklist_filename` should be renamed to `opcache.exclude_list_filename`.
  Many other PHP tools have already made changes in this regard : [PHPUnit](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-9.3.md#930---2020-08-07), [Drupal](https://www.drupal.org/project/drupal/issues/2993575), [Xdebug](https://github.com/xdebug/xdebug/commit/63b43b51e43b794cf8cd740e54089b2b7320fbe1), [Yii](https://github.com/yiisoft/yii2/pull/18104), [Composer](https://github.com/composer/composer/pull/8957) (+ [working with non-master Git branches](https://blog.packagist.com/composer-and-default-git-branches/)).

  C’est certainement intéressant aussi de songer à ces renommages chez nous également, utilisés à quelques endroits.

• Why ffmpeg can play h264 even when flag —disable-libx264 is set ? [closed]

  2 décembre 2020, par Jams

  To be complient with x264 licensing (for a commercial software I'm making) I plan to use a compiled version of ffmpeg without x264 support.
Here is the ouput of the command line ffmpeg -L :

  


  


  ffmpeg version n4.3.1-20-g8a2acdc6da Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9.3-win32 (GCC) 20200320
configuration : —prefix=/ffbuild/prefix —pkg-config-flags=—static —pkg-config=pkg-config —cross-prefix=x86_64-w64-mingw32- —arch=x86_64 —target-os=mingw32 —enable-version3 —disable-debug —enable-shared —disable-static —disable-debug —enable-iconv —enable-zlib —enable-libxml2 —enable-libfreetype —enable-libfribidi —enable-gmp —enable-lzma —enable-fontconfig —enable-opencl —enable-libvmaf —disable-vulkan —enable-libvorbis —enable-amf —enable-libaom —disable-avisynth —enable-libdav1d —disable-libdavs2 —enable-ffnvcodec —enable-cuda-llvm —disable-libglslang —enable-libass —enable-libbluray —enable-libmp3lame —enable-libopus —enable-libtheora —enable-libvpx —enable-libwebp —enable-libmfx —enable-libopencore-amrnb —enable-libopencore-amrwb —enable-libopenjpeg —enable-librav1e —enable-schannel —enable-sdl2 —enable-libsoxr —enable-libsrt —enable-libtwolame —disable-libvidstab —disable-libx264 —disable-libx265 —disable-libxavs2 —disable-libxvid —enable-libzimg —extra-cflags=-DLIBTWOLAME_STATIC —extra-cxxflags= —extra-ldflags=-pthread —extra-libs=-lgomp
libavutil 56. 51.100 / 56. 51.100
libavcodec 58. 91.100 / 58. 91.100
libavformat 58. 45.100 / 58. 45.100
libavdevice 58. 10.100 / 58. 10.100
libavfilter 7. 85.100 / 7. 85.100
libswscale 5. 7.100 / 5. 7.100
libswresample 3. 7.100 / 3. 7.100
ffmpeg is free software ; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation ; either version 3 of the License, or
(at your option) any later version.

  


  


  But when I play a video encoded with h264 it plays perfectly.
Is expected ? How to be sure I'm not infringing the license ?

  


  Here is where I downloaded the binaries :
https://github.com/BtbN/FFmpeg-Builds/releases
  
And I picked a release with the following name : win64-gpl-shared-4.3.zip

  


  Thanks.