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2 votes

Seeking Tool(s) to Restack Frames from an MP4 Video of a Total Solar Eclipse to Keep the Sun Always Centered

Start by converting your images into a video. Based on your question, I'm assuming you either have done this or know how to do it. You can then take your file into After Effects, and use a stabilizer ...
Cam's user avatar
  • 186
1 vote

ffmpeg input -ss accuracy

MPEG-TS don't have a global keyframe index ,so even input -ss will seek to the next KF after the ss timestamp. Add -copyts -start_at_zero and seek to a few seconds earlier. Then add a trim filter with ...
Gyan's user avatar
  • 33.3k
1 vote
Accepted

Impact of reencoding an HEVC file: How much loss if I do it in two steps, vs. going directly to a lower bitrate?

Is there a benefit to go back to the original file and reencode it at 40Mb/sec bitrate, vs. using the already reduced 50Mb/sec file and reencoding that one at 40Mb/sec? Every single time you reencode ...
veppy's user avatar
  • 81
1 vote

How do I get better sound quality when screencasting with ffmpeg without having to increase -r?

For x11grab you should be using -framerate and not -r. Here is what you should use: ffmpeg -f x11grab -framerate 25 -s ${dimensions} -i ${DISPLAY} -f alsa -ac 2 -i default -c:v libx264rgb -crf 0 -...
veppy's user avatar
  • 81
1 vote

Why does setting the bitrate with ffmpeg has no affect on the filesize?

The default encoder for mpegts is mpeg2video (producing a H.262 bitstream). This is an ancient encoder for an ancient codec and it is not capable of supporting a 1k or 0.5k video. Even modern codecs ...
veppy's user avatar
  • 81
1 vote

verify lossless in H.264

Just do this: ffmpeg -i $input -i $output -lavfi ssim -f null - This will compare the two videos using SSIM. If it's lossless then you will see: SSIM Y:1.000000 (inf) U:1.000000 (inf) V:1.000000 (inf)...
veppy's user avatar
  • 81
1 vote

Best ffmpeg compression settings for fast seeking of long 4 hour clip

I'd recommend considering these workarounds in this order, until it seeks fast enough: Make sure hardware video decoding is turned on Switch to a faster video player Decrease the GOP to one second ...
veppy's user avatar
  • 81
1 vote

Add an image overlay in front of video using ffmpeg

If you wanna resize the image. ffmpeg -i input.mp4 -i image.png -filter_complex "[1:v]scale=480:854[overlay]; [0:v][overlay]overlay=0:0:enable='between(t,0,20)'" -pix_fmt yuv420p -c:a copy ...
requizm's user avatar
  • 11

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