A method of testing the operation of an electronic device comprising a display and a video player, comprising the steps of: making (S 1, S 2) one or more test video sequences available to the video player, each test video sequence comprising video frames (1, 1 t, 1 t+1) that each has at least one visual metric (2, 2 t, 2 t+1) reflecting a known characteristic of the video frame; instructing (S 3, S 4) the video player to render at least a portion of said one or more test video sequences in a prescribed manner on said display; capturing (S 6) the rendered portion of said one or more test video sequences; decoding (S 7) the at least one visual metric associated with at least one of the video frames located in the captured portion of said one or more test video sequences; checking (S 5, S 7 -S 9) if the video player has correctly rendered the portion of said one or more test video sequences in said prescribed manner based on said decoded visual metric; characterized in that the step (S 6) of capturing the rendered portion is performed through a video camera pointed at the display of the electronic device, in that said at least one visual metric is a two-dimensional barcode (2, 2 t, 2 t+1) identifying uniquely a video frame number within the test video sequences, the location of said at least one visual metric (2, 2 t, 2 t+1) within a video frame (1, 1 t, 1 t+1) being moved each video frame, cycling through a number of non-overlapping locations in the video frame, and in that the checking step comprises generating (S 7) a video capture log comprising at least each frame number extracted from the visual metrics associated with the captured frames and a time at which the corresponding frame was captured and an event log corresponding to said prescribed manner according to which said video player has been instructed to render the at least a portion of said one or more test video sequences, and comparing the timing and sequencing of frame numbers extracted from the decoded visual metrics with an expected timing and sequencing of frame numbers by comparing said video capture log to said event log. making (S 1, S 2) one or more test video sequences available to the video player, each test video sequence comprising video frames (1, 1 t, 1 t+1) that each has at least one visual metric (2, 2 t, 2 t+1) reflecting a known characteristic of the video frame; instructing (S 3, S 4) the video player to render at least a portion of said one or more test video sequences in a prescribed manner on said display; capturing (S 6) the rendered portion of said one or more test video sequences; decoding (S 7) the at least one visual metric associated with at least one of the video frames located in the captured portion of said one or more test video sequences; checking (S 5, S 7 -S 9) if the video player has correctly rendered the portion of said one or more test video sequences in said prescribed manner based on said decoded visual metric; characterized in that the step (S 6) of capturing the rendered portion is performed through a video camera pointed at the display of the electronic device, in that said at least one visual metric is a two-dimensional barcode (2, 2 t, 2 t+1) identifying uniquely a video frame number within the test video sequences, the location of said at least one visual metric (2, 2 t, 2 t+1) within a video frame (1, 1 t, 1 t+1) being moved each video frame, cycling through a number of non-overlapping locations in the video frame, and in that the checking step comprises generating (S 7) a video capture log comprising at least each frame number extracted from the visual metrics associated with the captured frames and a time at which the corresponding frame was captured and an event log corresponding to said prescribed manner according to which said video player has been instructed to render the at least a portion of said one or more test video sequences, and comparing the timing and sequencing of frame numbers extracted from the decoded visual metrics with an expected timing and sequencing of frame numbers by comparing said video capture log to said event log.