Small size picuture will get pure black output

[Kiyamou]

Small size picuture will get pure black output. The problem isn't related with picture content, only related to picture size.

A interesting fact, I find the size threshold.
If input area >= 261120 ( 261120 = 408 * 640 ), output is normal.
If input area <= 261118 ( 261118 = 286 * 913 ), output is pure black.

[Selur]

same here with 640x352 source, using an input with a small resolution causes a black output.

[Kiyamou]

same here with 640x352 source, using an input with a small resolution causes a black output.

Indeed. It seems to depend on area (width * height).