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ffmpeg:video:resize [2025/01/29 22:23] peterffmpeg:video:resize [2025/01/29 22:37] (current) peter
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 [[ffmpeg:Video:Resize:Basic resize of a video|Basic resize of a video]] [[ffmpeg:Video:Resize:Basic resize of a video|Basic resize of a video]]
 +
 +[[ffmpeg:Video:Resize:Convert to 1080p (1920x1080)|Convert to 1080p (1920x1080)]]
  
 [[ffmpeg:Video:Resize:Convert to 4K (3840x2160)|Convert to 4K (3840x2160)]] [[ffmpeg:Video:Resize:Convert to 4K (3840x2160)|Convert to 4K (3840x2160)]]
  
 [[ffmpeg:Video:Resize:Maintain aspect ratio|Maintain aspect ratio]] [[ffmpeg:Video:Resize:Maintain aspect ratio|Maintain aspect ratio]]
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----- 
- 
-===== Upscaling Video to 1080p ===== 
- 
-<code bash> 
-ffmpeg -i input.mp4 -vf scale=1920x1080:flags=lanczos -c:v libx264 -preset slow -crf 21 output_compress_1080p.mp4 
- 
-# Using GPU. 
-ffmpeg -vaapi_device /dev/dri/renderD128 -i "input.mkv" -vf 'hwupload,scale_vaapi=w=1920:h=1080:format=nv12' -map 0:v -metadata:s:v:0 language=eng -c:v hevc_vaapi -map 0:a -metadata:s:a:0 language=eng -map 0:s? -metadata:s:s:0 language=eng -rc_mode CQP -global_quality 25 -c:a copy -c:s copy -profile:v main -v verbose output_1080p.mkv 
- 
-</code> 
- 
-<WRAP info> 
-**NOTE:**  Lanczos resampling involves a sinc filter as well. 
- 
-  * It is more computationally expensive but usually described as very high quality and can be used for up- and downsampling. 
- 
-</WRAP> 
- 
----- 
- 
-===== Upscaling Video to 4K ===== 
- 
-<code bash> 
-ffmpeg -i input.mp4 -vf scale=3840x2560:flags=lanczos -c:v libx264 -preset slow -crf 21 output_compress_4k.mp4 
-</code> 
- 
-==== Faster ==== 
- 
-<code bash> 
-ffmpeg -i input.mp4 -vf scale=3840x2560:flags=lanczos -c:v libx264 -preset veryfast -crf 25 output.mp4 
-</code> 
- 
-<WRAP info> 
-**NOTE:**  To achieve a faster upscale use a fast preset like **veryfast** or **superfast** however these will give a poorer compression but will complete the upscaling faster. 
- 
-  * Using a CRF of 25 will also lower the output quality slightly (less bitrate = less size). 
-  * Slower encoding means more quality is kept and the compression is superior. 
- 
-</WRAP> 
- 
----- 
- 
-===== Downscaling Video ===== 
- 
-<code bash> 
-ffmpeg -i input.mp4 -vf scale=640x480:flags=lanczos -c:v libx264 -preset slow -crf 21 output_compress_480p.mp4 
-</code> 
- 
----- 
- 
-===== Downscale or Downsize ===== 
- 
-<code bash> 
-ffmpeg -i input.mp4 -vf scale=1920:1080 -c:v libx264 smaller.mp4 
-</code> 
  
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ffmpeg/video/resize.1738189437.txt.gz · Last modified: 2025/01/29 22:23 by peter

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