Macos – How to install libav/avconv on Mac OS X or macOS 11

With the help of a ffmpeg contributor it was found out that both ffmpeg and libav create flawless lossless Quicktime files. The problem seems to be the graphic card driver displaying the videos wrongly (since GStream based players and VLC both display it wrongly, however VLC is exporting perfect PNGs of video frames). If you want to check if a video is really containing the frames pixel by pixel, try using

$ ffmpeg -i input.png -vcodec qtrle out.mov

$ ffmpeg -i input.png -f framecrc -
$ ffmpeg -i out.mov -f framecrc -

This will output frame data checksums.

For a visual comparison, convert the lossless video back to single frames and compare those.

Please, whenever you ask for help with avconv, attach its full output. Otherwise whoever replies has to resort to guessing.

My guess in this situation would be that your avconv (or more precisely libavcodec) isn't compiled with libx264, so the internal mpeg4 ASP encoder (with atrocious defaults) is used. So the solution is to get libavcodec with libx264 support - on Ubuntu you should install libavcodec-extra-53, otherwise you might need to compile on your own.