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Documentation says: "if kmin == 0, then key-frame insertion is disabled; and if kmax == 0, then all frames will be key-frames." Reading this, you'd expect that if kmax == 0, then with any kmin <= 0 all frames will be key-frames. But actually the kmin <= 0 test is caught first and you get the opposite (no keyframes but the first). You'd have instead to set kmax == 0 and any value kmin > 0, which is absolutely counter-intuitive (reversing order). Moreover kmax == 1 has no valid kmin (kmin == 1 conflicts with the `kmax > kmin` rule and kmin == 0 conflicts with `kmin >= kmax / 2 + 1`). So it should be considered an exception too. Instead I propose this new logic: - kmax == 1 means that all frames are keyframes (you are explicitly requesting a keyframe every 1 frame at most, i.e. all frames). - kmax == 0 means no keyframes (you ask for a keyframe every 0 frames, i.e. never). This is more "logical" language-wise, and also does not involve any conflicts about what if both kmax and kmin are 0, since now a single property value is meaningful for the 2 exceptional cases. Change-Id: Ia90fb963bc26904ff078d2e4ef9f74b22b13a0fd (cherry picked from commit 2dc0bdcaeee77ae8b40ff9eb82a9e03a7cecaf04)