When we get data from a movie file, we don't know how many samples we will get, but ffmpeg will not give us partial samples - that also means that it will not split a stereo sample up, either. In addition, most audio can have more than one channel for stereo or surround, so for example, if the sample is in stereo, the samples will come 2 at a time.

Example sample rates are 22,050 and 44,100 samples per second, which are the rates used for radio and CD respectively. Sounds are recorded at a certain sample rate, which simply says how fast to play each sample, and is measured in number of samples per second. Each sample represents a value of the audio waveform. Digital audio consists of a long stream of samples. It takes as arguments an SDL_AudioSpec struct, which contains all the information about the audio we are going to output.īefore we show how you set this up, let's explain first about how audio is handled by computers. The SDL_OpenAudio() function is used to open the audio device itself. SDL also gives us methods for outputting sound.

Printable version Text version Tutorial 03: Playing Sound Code: tutorial03.c Audio

Sdl2 ffmpeg tutorial