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User:David.humphrey/Audio Data API 2: Difference between revisions
→nsIDOMHTMLAudioElement additions
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void mozWriteAudio(array); | void mozWriteAudio(array); | ||
void | void mozCurrentSampleOffset(); | ||
</pre> | </pre> | ||
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# '''volume''' - the initial volume to use (e.g., 1.0) | # '''volume''' - the initial volume to use (e.g., 1.0) | ||
The choices made for '''channel''' and '''rate''' are significant, because they determine the frame size you must use when passing data to '''mozWriteAudio()'''. That is, you must pass either pass an array with 0 elements--similar to flushing the audio stream--or enough data for each channel specified in '''mozSetup()'''. | The choices made for '''channel''' and '''rate''' are significant, because they determine the frame size you must use when passing data to '''mozWriteAudio()'''. That is, you must pass either pass an array with 0 elements--similar to flushing the audio stream--or enough data for each channel specified in '''mozSetup()'''. | ||
The '''mozSetup()''' method, if called more than once, will recreate a new audio stream (destroying an existing one if present) with each call. Thus it is safe to call this more than once, but unnecessary. | |||
The '''mozWriteAudio()''' method can be called after '''mozSetup()'''. It allows audio data to be written directly from script. It takes one argument: | The '''mozWriteAudio()''' method can be called after '''mozSetup()'''. It allows audio data to be written directly from script. It takes one argument: | ||
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# '''array''' - this is a JS Array (e.g., new Array()) or a typed array (e.g., new Float32Array()) containing the audio data (floats) you wish to write. It must be 0 or N (where N % channels == 0) elements in length, otherwise a DOM error occurs. | # '''array''' - this is a JS Array (e.g., new Array()) or a typed array (e.g., new Float32Array()) containing the audio data (floats) you wish to write. It must be 0 or N (where N % channels == 0) elements in length, otherwise a DOM error occurs. | ||
The '''mozCurrentSampleOffset()''' method can be called after '''mozSetup()'''. It returns the current position (measured in samples) of the audio stream. This is useful when determining how much data to write with '''mozWriteAudio()'''. | |||
All of '''mozWriteAudio()''', '''mozCurrentSampleOffset()''', and '''mozSetup()''' will throw exceptions if called out of order. | |||
== Additional Resources == | == Additional Resources == | ||