1. A non-transitory computer readable recording medium storing a computer-executable program, when executed by a computer of a communication terminal device used in a teleconference through a network, causing the communication terminal device to execute: an acquiring instruction of acquiring, through a communication unit of the communication terminal connected to the network, video data including a compressed image from counter party devices including at least a first counter party device and a second counter party device, the first counter party device and second counter party device being counter partied of the teleconference; a storage control instruction of sequentially storing the compressed image included in the acquired video data in a storage area according to an order in which the compressed images have been acquired; a first determination instruction of determining whether a number of unprocessed compressed images is greater than a threshold, the unprocessed compressed images being the compressed images which are stored in the storage area and have not been subjected to a decoding process; a second determination instruction of second determining whether an image type of the compressed image is a predetermined type; and a decoding control instruction of: decoding the compressed image when the first determination instruction determines that the number of the unprocessed compressed images is not greater than the threshold and when the second determination instruction determines that the image type of the compressed image is the predetermined type; and not decoding the compressed image when the first determination instruction determines that the number of the unprocessed compressed images is greater than the threshold and when the second determination instruction determines that the image type of the compressed image is not the predetermined type.