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• Evolution #3237: Utiliser medium-editor

  15 February 2021, by RastaPopoulos ♥

  Moui mof, quand on fait la live demo, ya plein de soucis, ça active le bouton "B" (gras) même quand on est sur un lien ou un H4, H5, etc, alors que ya pas strong dessus, juste parce qu’en CSS ya le style gras ou je sais pas… L’éditeur de lien est horrible : on peut juste en ajouter mais quand on est sur un morceau de texte qui a déjà un lien et qu’on clique dessus : ça supprime entièrement le lien ! et plusieurs autres soucis et manques dans ce genre… c’est vraiment pas le meilleur éditeur wysiwyM que j’ai pu utiliser…

• FFmpeg conversion to Photo-JPEG is blocky [duplicate]

  26 May 2017, by Richard210363

  This question already has an answer here:

  • ffmpeg generate higher quality images for MJPEG encoding
    
    1 answer
    

  I am converting .mp4 files to .mov with the Photo-JPEG codec to use in After Effects to reduce render times.

  I have looked up the FFmpeg commands to do this and come up with:

  ffmpeg -i tower-bridge.mp4 -an -pix_fmt yuvj420p -vcodec mjpeg -f mov -y tower-bridge.mov 

  This works but when I look at the output video it is quite blocky; like a mosaic.

  During the conversion I get this message:

  [swscaler @ 0000000008c97fe0] deprecated pixel format used, make sure you did set range correctly

  Research on-line suggests I can ignore this message.

  What can I do to improve the output quality?

  MediaInfo report on Input file:

  Complete name : F:\london-tower-bridge.mp4
  Format : MPEG-4
  Format profile : Base Media
  Codec ID : isom (isom/avc1/mp42)
  File size : 18.7 MiB
  Duration : 13 s 625 ms
  Overall bit rate : 11.5 Mb/s
  

  ID : 1
  Format: AVC
  Format/Info : Advanced Video Codec
  Format profile : Baseline@L4
  Format settings, CABAC : No
  Format settings, ReFrames : 3 frames
  Codec ID : avc1
  Codec ID/Info : Advanced Video Coding
  Duration : 13 s 625 ms
  Bit rate : 11.5 Mb/s
  Maximum bit rate : 26.8 Mb/s
  Width : 1 920 pixels
  Height : 1 080 pixels
  Display aspect ratio : 16:9
  Frame rate mode : Constant
  Frame rate : 24.000 FPS
  Color space : YUV
  Chroma subsampling : 4:2:0
  Bit depth : 8 bits
  Scan type : Progressive
  Bits/(Pixel*Frame) : 0.231
  Stream size : 18.7 MiB (100%)
  Writing library : Zencoder Video Encoding System
  

  MediaInfo report on Output file:

  Complete name : F:\london-tower-bridge.mov
  Format : MPEG-4
  Format profile : QuickTime
  Codec ID : qt 0000.02 (qt )
  File size : 16.1 MiB
  Duration : 13 s 625 ms
  Overall bit rate mode : Variable
  Overall bit rate : 9 912 kb/s
  Writing application : Lavf57.72.101
  

  ID : 1
  Format : JPEG
  Codec ID : jpeg
  Duration : 13 s 625 ms
  Bit rate mode : Variable
  Bit rate : 9 910 kb/s
  Width : 1 920 pixels
  Height : 1 080 pixels
  Display aspect ratio : 16:9
  Frame rate mode : Constant
  Frame rate : 24.000 FPS
  Color space : YUV
  Chroma subsampling : 4:2:0
  Bit depth : 8 bits
  Scan type : Progressive
  Compression mode : Lossy
  Bits/(Pixel*Frame) : 0.199
  Stream size : 16.1 MiB (100%)
  Language : English
  

• Why after rendering with ffmpeg, file size did not decrease?

  15 April 2021, by ptrra

  PROBLEM: After rendering a certain video with ffmpeg file size increased from 4GB to 6GB.
  
ORIGINAL VIDEO: EE1.mkv
  
FFMPEG COMMAND: ffmpeg -i EE1.mkv -c:a copy -c:v libx264 -crf 23 -preset medium -profile:v high out.mp4
  
QUESTIONS: Why did the file size increase? What am I doing wrong?

  


  !DETAILS!
  
After a few years I made about 30 gaming videos (130GB) and with the current covid-19 situation I started recording my online classes (about 40 videos or 150GB). Now because I'm lacking space on my 1TB external HDD I started getting into ffmpeg. Before I was only using obs-studio and not good parameters for recording.

  


  I was using CBR mode for recording, either 5000KB or 15000KB bit rate with varying x264 presets and profiles because I was also experimenting with them. Usually superfast preset with high profile. So I wanted to convert all those videos with ffmpeg using CRF 23, medium preset and high profile. A note that when I'm recording with obs-studio it's set to record in matroska format (.mkv).

  


  When I was rendering my online classes videos with these settings I managed to achieve 10x better compression with the same quality. And when rendering my gaming videos I managed to achieve up to 3x better compression with the same quality. However there is this one video that when rendered with the same parameters the file size increases.

  


  The EE1.mkv should be recorded with CBR 15000KB bit rate, with superfast preset and high profile. Also the game that is recorded in this video is Empire Earth which needs around 8000KB for it to look good. Everything more than 8000KB is not needed.

  


  Thank you all for your help.