VideoSound

Scaleform::GFx::Video::VideoSound

class VideoSound : public RefCountBaseNTS<VideoSound,Stat_Video_Mem>;

VideoSound object represents a stream of audio data for a single video file playing within GFx. VideoSound objects are created by the VideoSoundSystem::Create function; they are further initialized by CreateOutput. After creation, GFx calls Start, Stop, Pause and other functions of the sound object to tell it when to start and stop streaming data. 

VideoSound receives its PCM data by polling it from the video player through the PCMStream interface passed to the Start function. PCM data can be requested in either 16-bit integer or 32-bit floating point format; users specify the desired format by implementing the GetPCMFormat function. The actual polling process typically takes place on a separate thread created by the sound or VideoSoundSystem. 

The following is a detailed sequence of events that takes place with VideoSound object:

1. VideoSound is created by VideoSoundSystem::Create.
2. CreateOutput is called to initialize the sound stream, specifying the number of channels and the sample rate.
3. Start is called to begin audio streaming. At this point, VideoSound implementaion should begin polling PCMStream for audio data.
4. Pause is called to temporarily stop and resume playback without losing position within the audio stream.
5. Stop completes sound playback; after this function is called PCMStream should no longer be polled.
6. DestroyOutput shuts down the sound channel.
7. VideoSound destructor is called at some point later on once its reference count goes down to zero.

Throughout its lifetime, VideoSound is responsible for maintaining its Status state and reporting it properly from the GetStatus() function. The status starts out in Sound_Stopped state and transitions to Sound_Playing when Start is called. The other status states include Sound_Paused and Sound_Error.

Video_Video.h