ffmpeg with background color

This command works nice with some GIF but with some others return a error:

ffmpeg -f gif -f lavfi -i color=FFFFFF -i animated.gif -y 
   -filter_complex "[0][1]scale2ref[bg][gif];[bg]setsar=1[bg];[bg][gif]overlay=shortest=1"
   -pix_fmt yuv420p -movflags frag_keyframe+empty_moov -movflags +faststart
   -crf 20 -b:v 500k -f mp4 animated.mp4

Error:

[libx264 @ 0x55e79dc7e3c0] height not divisible by 2 (1400x933)
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0
- maybe incorrect parameters such as bit_rate, rate, width or height

Some help to fix it maintaining the background color functionality?

Solution

Use

ffmpeg -f gif -f lavfi -i color=FFFFFF -i animated.gif -y -filter_complex "[0][1]scale2ref[bg][gif];[bg]setsar=1[bg];[bg][gif]overlay=shortest=1,scale=w='2*trunc(iw/2)':h='2*trunc(ih/2)'" -pix_fmt yuv420p -movflags frag_keyframe+empty_moov -movflags +faststart -crf 20 -b:v 500k -f mp4 animated.mp4

For yuv420p input, x264 requires that the width and height both be even numbers.