I have an HD video that is a presentation, so it consists mostly of still images. It's a 50 minute, 200MB MP4 file, downloaded from YouTube.
Is there a way to take advantage of the static nature of the content to compress it further?
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3When you encode to MP4 using FFmpeg/x264, the encoder flags duplicate frames and writes a minimal packet for that frame, around 30-40 bytes.– GyanCommented Jun 26, 2016 at 18:26
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@Mulvya I downloaded that video from Youtube using Youtube-dl. I'm not sure how it's encoded. I used settings from your answer and reduced file size to half without any visible quality loss.– Mark EvansCommented Jun 26, 2016 at 18:30
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You can increase CRF value for a greater reduction. Say, upto 27.– GyanCommented Jun 26, 2016 at 18:43
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Is the video a direct screen capture, or a camera recording?– grawity_u1686Commented Jun 27, 2016 at 7:33
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@grawity screen capture. Audio is at 192k, so around 68MB and video is 130MB together 198MB. Video is already encoded using x265.– Mark EvansCommented Jun 27, 2016 at 8:13
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1 Answer
You can use FFmpeg, a command-line tool,
ffmpeg -i in.mp4 -crf 23 -preset slow -b:a 96k out.mp4
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Is there any without changing bitrate or losing quality. The video mostly has still images. So video has same frame for like 3 mins. Currently testing with one video, I will get back to you. Commented Jun 26, 2016 at 17:33
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1You could try identifying the bitrate using
mediainfoand then using that as your ffmpeg preset. By definition, you're re-encoding the video, so you're going to lose some quality.– picobitCommented Jun 26, 2016 at 18:09 -
Bitrate = how many bits a second of source material occupies. Your goal here is to reduce bitrate without loosing quality. If you won't change bitrate and video length, you'll get the same size. Commented Oct 22, 2019 at 13:13
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Assuming 24 FPS and HD resolution (1280x720) with 8-bit RGB color that would be 66GB of uncompressed data after 50 minutes. So those 200MB are already only 0.3% of the original data. I doubt you can reduce that any further without loosing details.– U. WindlCommented Nov 8, 2023 at 11:17