+#define RETRO_ENVIRONMENT_GET_INPUT_MAX_USERS 61
+ /* unsigned * --
+ * Unsigned value is the number of active input devices
+ * provided by the frontend. This may change between
+ * frames, but will remain constant for the duration
+ * of each frame.
+ * If callback returns true, a core need not poll any
+ * input device with an index greater than or equal to
+ * the number of active devices.
+ * If callback returns false, the number of active input
+ * devices is unknown. In this case, all input devices
+ * should be considered active.
+ */
+
+#define RETRO_ENVIRONMENT_SET_AUDIO_BUFFER_STATUS_CALLBACK 62
+ /* const struct retro_audio_buffer_status_callback * --
+ * Lets the core know the occupancy level of the frontend
+ * audio buffer. Can be used by a core to attempt frame
+ * skipping in order to avoid buffer under-runs.
+ * A core may pass NULL to disable buffer status reporting
+ * in the frontend.
+ */
+
+#define RETRO_ENVIRONMENT_SET_MINIMUM_AUDIO_LATENCY 63
+ /* const unsigned * --
+ * Sets minimum frontend audio latency in milliseconds.
+ * Resultant audio latency may be larger than set value,
+ * or smaller if a hardware limit is encountered. A frontend
+ * is expected to honour requests up to 512 ms.
+ *
+ * - If value is less than current frontend
+ * audio latency, callback has no effect
+ * - If value is zero, default frontend audio
+ * latency is set
+ *
+ * May be used by a core to increase audio latency and
+ * therefore decrease the probability of buffer under-runs
+ * (crackling) when performing 'intensive' operations.
+ * A core utilising RETRO_ENVIRONMENT_SET_AUDIO_BUFFER_STATUS_CALLBACK
+ * to implement audio-buffer-based frame skipping may achieve
+ * optimal results by setting the audio latency to a 'high'
+ * (typically 6x or 8x) integer multiple of the expected
+ * frame time.
+ *
+ * WARNING: This can only be called from within retro_run().
+ * Calling this can require a full reinitialization of audio
+ * drivers in the frontend, so it is important to call it very
+ * sparingly, and usually only with the users explicit consent.
+ * An eventual driver reinitialize will happen so that audio
+ * callbacks happening after this call within the same retro_run()
+ * call will target the newly initialized driver.
+ */
+