| I just noticed you have one for "Create single-image video with audio". This seemingly easy task is actually pretty hard to get right with FFMPEG. Just leave a few notes here if anyone want to use that. Video part Chroma sampling Without any `pix_fmt` argument, FFMPEG defaults to 4:4:4 instead of typical 4:2:0. Which has very limited support (for example, Firefox doesn't support it.) To fix: add `pix_fmt yuv420p`, or chain a `format=yuv420p` vf at the end to your other vf(s). Color space FFMPEG by default uses BT.601 when converting your RGB images into YUV. This is an issue if your image / output video is in HD resolution. Almost all video players (including browsers) would assume BT.709 for anything >=720P. This causes color to shift in playback（255,0,0 would become 255,24,0). To fix: add `-vf zscale=matrix=709`. Note: there are some other video filters can do the same. The most famous being good ol' `scale` (based on libswscale). However, it has a notorious bug that would cause the color to shift on its own (becomes yellow) if the input is in BGR (all the `.bmp`s). See: https://trac.ffmpeg.org/ticket/979 So stick with better `zscale`. Framerate etc. You can set framerate with `-r` to a small number for both input (reading the same image X times per second) and output (since it's a still image, you can get away with very low framerate. `-tune stillimage` should also be used for (default) x264 encoder. In summary: ffmpeg -loop 1 -r 1 -i image.png -i audio.wav -r 1 -shortest -vf zscale=matrix=709,format=yuv420p -c:v libx264 -tune stillimage output_video.mp4 Audio part - length mismatch bug Even if we ignore all the image/video troubles above, `ffmpeg -loop 1 -i image.png -i sound.mp3 -shortest video.mp4` still doesn't work well. "-shortest" argument has a long-standing bug (https://trac.ffmpeg.org/ticket/5456) that is the output video would be longer than your input audio (by quite a few seconds, worse if using -r 1). There are some workarounds (listed in the ticket) but they don't eliminate the issue entirely. Your best bet (if the length match is crucial) is to just convert the output video again and use -t to cut to the proper length. |