utils_video_encoding
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utils_video_encoding [2020/06/14 18:49] xavier |
utils_video_encoding [2020/06/18 16:19] (current) xavier |
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| - | ====== Video compression commands and explanations ====== | + | ====== Video encoding (ffmpeg) commands and explanations ====== |
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| + | ===== Compress video stream ===== | ||
| Compression without important video quality loss (tested with relatively low quality full HD source):\\ | Compression without important video quality loss (tested with relatively low quality full HD source):\\ | ||
| ''$ ffmpeg -i input -vcodec libx265 -crf 24 output''\\ | ''$ ffmpeg -i input -vcodec libx265 -crf 24 output''\\ | ||
| => -crf is the compression factor. Lower is better, 24 is about as low as is useful for libx265\\ | => -crf is the compression factor. Lower is better, 24 is about as low as is useful for libx265\\ | ||
| + | => -map 0 to keep all streams (audio, subtitles, but also video)\\ | ||
| => Use -vf scale=-1:720 to resize to 720p (keeping aspect ratio with -1, resulting in calculation of width)\\ | => Use -vf scale=-1:720 to resize to 720p (keeping aspect ratio with -1, resulting in calculation of width)\\ | ||
| - | => Use -map 0 to keep all streams (audio, subtitles, but also video) | + | |
| + | ===== Select language streams ===== | ||
| + | |||
| + | Do not re-encode streams, keep all subtitles and select English and French audio languages:\\ | ||
| + | ''$ ffmpeg -i input -map 0:v -map 0:s -map 0:m:language:eng -map 0:m:language:fre? -c copy output''\\ | ||
| + | => -c copy to avoid re-encoding streams\\ | ||
| + | => -map:0:v to keep all video streams\\ | ||
| + | => -map 0:s to keel all subtitle streams\\ | ||
| + | => -map 0:m:language:eng to keep streams with english metadata defined (all types of streams but impacting only audio (a) since we're keeping all subtitles in this case)\\ | ||
| + | => the ? at the end of -map instruction avoids failure if the matching input is missing\\ | ||
| + | |||
| + | ===== Script examples ===== | ||
utils_video_encoding.1592160543.txt.gz · Last modified: 2020/06/14 18:49 by xavier
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