SHMUP postmortem: How to generate videos from iPhone
Summary
To demo the work in progress required to generate videos, a task far from being trivial on a smartphone: Slow CPU/GPU, Little RAM, no TV output, no storage space, no real multitasking. But on a mobiles device none of those are possible because of the following constraints: • Very limited CPU/GPU power: An additional process, grabbing the framebuffer each frame would kill the framerate. With an appropriate structure, user inputs are timestamped as soon as they are received from the touchscreen or the network: This is not the only thing to do in order to be able to replay a session accurately. Additionally the timer can behave differently upon video generation and return a constant 16.666ms delta in order to dissociate realtime and simulation time. Here are the data structures we need: At the end of the replay we save the buffer as a WAVE as follow: This is for a 22500Hz, mono, 8bits WAV but it can easily be converted to any combination of Stereo/16bits/Frequency.