A method comprising: accessing information indicating that a first set of one or more consecutive pictures from a video sequence are not to be displayed; accessing information indicating that a second set of one or more consecutive pictures from the video sequence are not to be displayed, the second set being separate from the first set in the video sequence; the method being characterized in that it comprises: determining a first indicator, the first indicator indicating an amount of distortion associated with a given type of distortive effect, from among multiple types of distortive effects that result from displaying the video sequence with a same first picture displayed during a display time for the first set of pictures; determining a second indicator, the second indicator indicating an amount of distortion associated with the given type of distortive effect, from among the multiple types of distortive effects that result from displaying the video sequence with a same second picture displayed during a display time for the second set of pictures; combining (1050, 542) the first indicator and the second indicator to produce a combined indicator of distortion for the given type of distortive effect; determining a third indicator, the third indicator indicating an amount of distortion associated with an additional type of distortive effect, from among the multiple types of distortive effects that result from displaying the video sequence with the same first picture displayed during the display time for the first set of pictures, the additional type of distortive effect being distinct from the given type of distortive effect, determining a fourth indicator, the fourth indicator indicating an amount of distortion associated with the additional type of distortive effect from among the multiple types of distortive effects that result from displaying the video sequence with the same second picture displayed during the display time for the second set of pictures; and combining the third indicator and the fourth indicator to produce an additional combined indicator of distortion that indicates distortion for the additional type of distortive effect. accessing information indicating that a first set of one or more consecutive pictures from a video sequence are not to be displayed; accessing information indicating that a second set of one or more consecutive pictures from the video sequence are not to be displayed, the second set being separate from the first set in the video sequence; determining a first indicator, the first indicator indicating an amount of distortion associated with a given type of distortive effect, from among multiple types of distortive effects that result from displaying the video sequence with a same first picture displayed during a display time for the first set of pictures; determining a second indicator, the second indicator indicating an amount of distortion associated with the given type of distortive effect, from among the multiple types of distortive effects that result from displaying the video sequence with a same second picture displayed during a display time for the second set of pictures; combining (1050, 542) the first indicator and the second indicator to produce a combined indicator of distortion for the given type of distortive effect; determining a third indicator, the third indicator indicating an amount of distortion associated with an additional type of distortive effect, from among the multiple types of distortive effects that result from displaying the video sequence with the same first picture displayed during the display time for the first set of pictures, the additional type of distortive effect being distinct from the given type of distortive effect, determining a fourth indicator, the fourth indicator indicating an amount of distortion associated with the additional type of distortive effect from among the multiple types of distortive effects that result from displaying the video sequence with the same second picture displayed during the display time for the second set of pictures; and combining the third indicator and the fourth indicator to produce an additional combined indicator of distortion that indicates distortion for the additional type of distortive effect.