Anuj TBE:

I'm using ffmpeg to generate slideshow with images input from web

ffmpeg  \
-loop 1 -t 5 -i http://ift.tt/2AA2v7c \
-loop 1 -t 5 -i http://ift.tt/2ykO5BS \
-loop 1 -t 5 -i http://ift.tt/2AzbMg7 \
-loop 1 -t 5 -i http://ift.tt/2yl3VfR \
-loop 1 -t 5 -i http://ift.tt/2AAFFN2 \
-filter_complex \
"[0:v]setdar=16/9,fade=t=out:st=4:d=1[v0]; \
 [1:v]setdar=16/9,fade=t=in:st=0:d=1,fade=t=out:st=4:d=1[v1]; \
 [2:v]setdar=16/9,fade=t=in:st=0:d=1,fade=t=out:st=4:d=1[v2]; \
 [3:v]setdar=16/9,fade=t=in:st=0:d=1,fade=t=out:st=4:d=1[v3]; \
 [4:v]setdar=16/9,fade=t=in:st=0:d=1,fade=t=out:st=4:d=1[v4]; \
 [v0][v1][v2][v3][v4]concat=n=5:v=1:a=0,format=yuv420p[v]" -map "[v]" out.mp4

But after processing the videos, it gives error as

[Parsed_concat_14 @ 0x3e5e9e0] Input link in1:v0 parameters (size 1024x709, SAR 709:576) do not match the corresponding output link in0:v0 parameters (500x281, SAR 1124:1125)
[Parsed_concat_14 @ 0x3e5e9e0] Failed to configure output pad on Parsed_concat_14
Error configuring complex filters.
Invalid argument

Is it related to scaling of images, since images could be different dimensions.

Also, how to scale the images to fit 16:9 ratio may be using crop or fit?