HTML5 media playback is important for enabling multi-channel AAC content delivery to the consumer. This is because the resampler for WaveOut was changed in Win7 to use linear interpolation, according to Microsoft. Windows 7 applications that use the WaveOut API will have poor audio quality on playback if the sample rate of the content is not the same as the default sample rate of the output device. Perhaps for this reason, or the fact it was already working code, IE 9 and Chrome apparently chose to use waveOut to play audio. This is supplied with Win 7, but in XP days, a user had to sometimes install DirectX seperately (usually with an application he or she installed) To use DirectSound, DirectX has to be installed on the PC.
The primary methods or APIs to play audio in Windows 7 are: Output Method To explain this problem, some background on audio playback in Windows needs to be understood. This page details a historical problem that existed with Internet Explorer and Chrome in Windows 7.
