Cut gif with FFmpeg while retaining quality?

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I'm attempting to cut a gif using -ss and -t in FFmpeg but it's drastically decreasing the quality in comparison to the original gif.

I'm using this command:

ffmpeg -y `
-i "S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.gif" `
-ss 1.65 -t 1.65 `
"S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo Short.gif"

I've tried using -c copy but I get an error saying Error writing trailer, I also see that there is a gif muxer -c:v gif but I can't seem to find any options for it.

Is what I'm attempting to do possible, cutting a gif without losing quality?

Full log:

PS C:\Windows\system32> ffmpeg -y `
>> -i "S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.gif" `
>> -ss 1.65 -t 1.65 `
>> "S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo Short.gif"
ffmpeg version N-94652-g808a6717e0 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9.1.1 (GCC) 20190807
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
  libavutil      56. 33.100 / 56. 33.100
  libavcodec     58. 55.101 / 58. 55.101
  libavformat    58. 31.104 / 58. 31.104
  libavdevice    58.  9.100 / 58.  9.100
  libavfilter     7. 58.101 /  7. 58.101
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, gif, from 'S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.gif':
  Duration: 00:00:04.01, start: 0.000000, bitrate: 34953 kb/s
    Stream #0:0: Video: gif, bgra, 853x480 [SAR 64:64 DAR 853:480], 30 fps, 30 tbr, 100 tbn, 100 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (gif (native) -> gif (native))
Press [q] to stop, [?] for help
Output #0, gif, to 'S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo Short.gif':
  Metadata:
    encoder         : Lavf58.31.104
    Stream #0:0: Video: gif, bgr8, 853x480 [SAR 1:1 DAR 853:480], q=2-31, 200 kb/s, 30 fps, 100 tbn, 30 tbc
    Metadata:
      encoder         : Lavc58.55.101 gif
frame=   49 fps= 40 q=-0.0 Lsize=    9301kB time=00:00:01.64 bitrate=46460.4kbits/s speed=1.33x
video:9301kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000210%

Original gif creation:

ffmpeg -y `
-i "S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.ts" `
-vf fps=30,scale=-1:480:flags=lanczos,palettegen `
"S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.png"
ffmpeg -y `
-i "S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.ts" `
-i "S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.png" `
-filter_complex "fps=30,scale=-1:480:flags=lanczos[x];[x][1:v]paletteuse" `
"S:\Videos\Saved Clips\PSW\Mad Wooloo\Mad Wooloo EL.gif"

Example Video Link

Nimble

Posted 2019-11-16T20:07:56.963

Reputation: 75

Share full log. – Gyan – 2019-11-17T15:58:20.363

I've added the full log to the end of the post originally via Pastebin, but it looks like someone edited it right into the post. Not sure why I didn't think to look through the log first but I can see that the pixel format is changing from bgra to bgr8, can't seem to keep it bgra though as the gif muxer says bgra is invalid. I'm also noticing that 100 tbc is changing to 30 tbc though I'm not sure that matters. Last but not least I'm noticing that the output gif only looks worse than the original once I post it in Discord, when viewed directly on my PC it looks fine... see video in post. – Nimble – 2019-11-17T19:17:45.947

Few more discoveries, the output gif looks fine when viewed on mobile Discord just not the desktop application. Furthermore, I can use the -c copy option just not in conjunction with 'accurate' seek, where I put -ss after the input. I can put -ss before the input but then I can't cut as accurately as I'm wanting. However, when I do get a command with -c copy to run the output looks fine on Desktop Discord, so definitely seeming like bgr8 is the culprit. Weird that bgra isn't compatible with the gif muxer, especially when considering that I created the gif using FFmpeg, see post. – Nimble – 2019-11-17T19:51:21.157

It was me who edited in the log. We prefer to have everything here. What I meant was showing the log that exhibits the error writing the GIF, not the one that succeeds. But yes, the pixel format may be the culprit. How are you getting -c copy to run though, when the pixel format cannot be written? And perhaps you can show the log from the original video creation. The GIF encoder cannot create bgra output… – slhck – 2019-11-17T21:21:18.780

I see what you mean about posting the log with the error, but I found that the error was popping because I was using -c copy in conjunction with 'accurate seek'. I can get -c copy to work when using the more inaccurate seek (where you put -ss before the input not after), but the problem is that I kinda need accurate seek to get the results I want. -c copy bypasses the gif muxer, basically when you invoke -c copy you're choosing not to re-encode, thus bgra is retained. In quite the pickle... can't use accurate seek with -c copy and can't use -pix_fmt bgra with gif muxer. – Nimble – 2019-11-17T21:43:27.677

I could cut the video before creating the gif, but seek (-ss) doesn't cut as exact on my video file as it does the gif file. I believe this is because the video has some unique / harsh settings (forced keyframe intervals, no scene changes, etc.) to ensure that it parts correctly using FFmpeg's -segment demuxer. I could cut the video to an exact frame with something like Adobe premiere but I find that Adobe's exports are multitudes larger than FFmpeg's and it's important to keep files as small as possible when sharing online in something like Discord. Once again, quite the pickle. – Nimble – 2019-11-17T21:51:39.890

No answers

Asked: 2019-11-16T20:07:56.963

Viewed: 39 times

Active: 2019-11-17T19:53:11.163