/**
* RecommendSampleFrameCount() returns the supported sample frame count
* closest to the requested count. The sample frame count determines the
* overall latency of audio. Since one "frame" is always buffered in advance,
* smaller frame counts will yield lower latency, but higher CPU utilization.
*
* Supported sample frame counts will vary by hardware and system (consider
* that the local system might be anywhere from a cell phone or a high-end
* audio workstation). Sample counts less than
* <code>PP_AUDIOMINSAMPLEFRAMECOUNT</code> and greater than
* <code>PP_AUDIOMAXSAMPLEFRAMECOUNT</code> are never supported on any
* system, but values in between aren't necessarily valid. This function
* will return a supported count closest to the requested frame count.
*
* RecommendSampleFrameCount() result is intended for audio output devices.
*
* @param[in] instance
* @param[in] sample_rate A <code>PP_AudioSampleRate</code> which is either
* <code>PP_AUDIOSAMPLERATE_44100</code> or
* <code>PP_AUDIOSAMPLERATE_48000.</code>
* @param[in] requested_sample_frame_count A <code>uint_32t</code> requested
* frame count.
*
* @return A <code>uint32_t</code> containing the recommended sample frame
* count if successful.
*/
public static uint RecommendSampleFrameCount(
PPInstance instance,
PPAudioSampleRate sample_rate,
uint requested_sample_frame_count)
{
return(_RecommendSampleFrameCount(instance,
sample_rate,
requested_sample_frame_count));
}
extern static PPResource _CreateStereo16Bit(PPInstance instance,
PPAudioSampleRate sample_rate,
uint sample_frame_count);
extern static uint _RecommendSampleFrameCount(
PPInstance instance,
PPAudioSampleRate sample_rate,
uint requested_sample_frame_count);
/**
* CreateStereo16bit() creates a 16 bit audio configuration resource. The
* <code>sample_rate</code> should be the result of calling
* <code>RecommendSampleRate</code> and <code>sample_frame_count</code> should
* be the result of calling <code>RecommendSampleFrameCount</code>. If the
* sample frame count or bit rate isn't supported, this function will fail and
* return a null resource.
*
* A single sample frame on a stereo device means one value for the left
* channel and one value for the right channel.
*
* Buffer layout for a stereo int16 configuration:
* <code>int16_t *buffer16;</code>
* <code>buffer16[0]</code> is the first left channel sample.
* <code>buffer16[1]</code> is the first right channel sample.
* <code>buffer16[2]</code> is the second left channel sample.
* <code>buffer16[3]</code> is the second right channel sample.
* ...
* <code>buffer16[2 * (sample_frame_count - 1)]</code> is the last left
* channel sample.
* <code>buffer16[2 * (sample_frame_count - 1) + 1]</code> is the last
* right channel sample.
* Data will always be in the native endian format of the platform.
*
* @param[in] instance A <code>PP_Instance</code> identifying one instance
* of a module.
* @param[in] sample_rate A <code>PP_AudioSampleRate</code> which is either
* <code>PP_AUDIOSAMPLERATE_44100</code> or
* <code>PP_AUDIOSAMPLERATE_48000</code>.
* @param[in] sample_frame_count A <code>uint32_t</code> frame count returned
* from the <code>RecommendSampleFrameCount</code> function.
*
* @return A <code>PP_Resource</code> containing the
* <code>PPB_Audio_Config</code> if successful or a null resource if the
* sample frame count or bit rate are not supported.
*/
public static PPResource CreateStereo16Bit(PPInstance instance,
PPAudioSampleRate sample_rate,
uint sample_frame_count)
{
return(_CreateStereo16Bit(instance, sample_rate, sample_frame_count));
}
