Move ppapi audio interface out of dev, but...

ppapi/c/ppb_audio_config.h

+/* Copyright (c) 2011 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef PPAPI_C_PPB_AUDIO_CONFIG_H_
+#define PPAPI_C_PPB_AUDIO_CONFIG_H_
+
+#include "ppapi/c/pp_bool.h"
+#include "ppapi/c/pp_instance.h"
+#include "ppapi/c/pp_macros.h"
+#include "ppapi/c/pp_resource.h"
+#include "ppapi/c/pp_stdint.h"
+
+#define PPB_AUDIO_CONFIG_INTERFACE "PPB_AudioConfig;1.0"
+
+enum {
+  PP_AUDIOMINSAMPLEFRAMECOUNT = 64,
+  PP_AUDIOMAXSAMPLEFRAMECOUNT = 32768
+};
+
+typedef enum {
+  PP_AUDIOSAMPLERATE_NONE = 0,
+  PP_AUDIOSAMPLERATE_44100 = 44100,
+  PP_AUDIOSAMPLERATE_48000 = 48000
+} PP_AudioSampleRate;
+PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_AudioSampleRate, 4);
+
+/**
+ * Audio configuration. This base configuration interface supports only stereo
+ * 16bit output. This class is not mutable, therefore it is okay to access
+ * instances from different threads.
+ */
+struct PPB_AudioConfig {
+  /**
+   * Create a 16 bit stereo config with the given sample rate. We guarantee
+   * that PP_AUDIOSAMPLERATE_44100 and PP_AUDIOSAMPLERATE_48000 sample rates
+   * are supported. The |sample_frame_count| should be the result of calling
+   * RecommendSampleFrameCount. If the sample frame count or bit rate aren'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:
+   * int16_t *buffer16;
+   * buffer16[0] is the first left channel sample
+   * buffer16[1] is the first right channel sample
+   * buffer16[2] is the second left channel sample
+   * buffer16[3] is the second right channel sample
+   * ...
+   * buffer16[2 * (sample_frame_count - 1)] is the last left channel sample
+   * buffer16[2 * (sample_frame_count - 1) + 1] is the last right channel sample
+   * Data will always be in the native endian format of the platform.
+   */
+  PP_Resource (*CreateStereo16Bit)(PP_Instance instance,
+                                   PP_AudioSampleRate sample_rate,
+                                   uint32_t sample_frame_count);
+
+  /*
+   * Returns a supported sample frame count closest to the given 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 PP_AUDIOMINSAMPLEFRAMECOUNT
+   * and greater than PP_AUDIOMAXSAMPLEFRAMECOUNT 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 value.
+   *
+   * If you pass 0 as the requested sample count, the recommended sample for
+   * the local system is returned.
+   */
+  uint32_t (*RecommendSampleFrameCount)(PP_AudioSampleRate sample_rate,
+                                        uint32_t requested_sample_frame_count);
+
+  /**
+   * Returns true if the given resource is an AudioConfig object.
+   */
+  PP_Bool (*IsAudioConfig)(PP_Resource resource);
+
+  /**
+   * Returns the sample rate for the given AudioConfig resource. If the
+   * resource is invalid, this will return PP_AUDIOSAMPLERATE_NONE.
+   */
+  PP_AudioSampleRate (*GetSampleRate)(PP_Resource config);
+
+  /**
+   * Returns the sample frame count for the given AudioConfig resource. If the
+   * resource is invalid, this will return 0. See RecommendSampleFrameCount for
+   * more on sample frame counts.
+   */
+  uint32_t (*GetSampleFrameCount)(PP_Resource config);
+};
+
+#endif  /* PPAPI_C_PPB_AUDIO_CONFIG_H_ */
+