Figure 2.2 is a graph with a frame size of 320 x 224 pixels, and Figure 2.3 is a picture of a natural picture movie without sound with Cinepak compression at 256 x 160 pixels. As can be seen from these figures, the compression rate worsens with higher image quality, and the data transfer rate increases. The actual movie will satisfy the following formula because it adds sound.

Sampling frequency x A x B + Image transfer rate <300KB / S …… (Formula 2.1)

 A: If 8bitPCM, A = 1
If 16bitPCM, A = 2
B: If monaural, B = 1
If stereo, B = 2 

Refer to the figure for the image transfer rate. However, since the actual compression rate varies depending on the contents of the movie, determine the frame size, frame rate, and sound with reference to these figures, compress the movie to be used, and set the transfer rate in the image quality setting. It is better to adjust.