Merge "audio policy: added flag for primary output"

 * frameworks/base/include/media/AudioSystem.h

 */

/* request to open a direct output with get_output() (by opposition to

 * sharing an output with other AudioTracks)

/* the audio output flags serve two purposes:

 * - when an AudioTrack is created they indicate a "wish" to be connected to an output stream with

 * attributes corresponding to the specified flags

 * - when present in an output profile descriptor listed for a particular audio hardware module,

 * they indicate that an output stream can be opened that supports the attributes indicated by

 * the flags.

 * the audio policy manager will try to match the flags in the request (when getOuput() is called)

 * to an available output stream.

 */

typedef enum {

    AUDIO_POLICY_OUTPUT_FLAG_NONE = 0x0,

    AUDIO_POLICY_OUTPUT_FLAG_DIRECT = 0x1

    AUDIO_POLICY_OUTPUT_FLAG_NONE = 0x0,    // no attributes

    AUDIO_POLICY_OUTPUT_FLAG_DIRECT = 0x1,  // this output directly connects a track to one output

                                            // stream (no software mixer)

    AUDIO_POLICY_OUTPUT_FLAG_PRIMARY = 0x2  // this output is the primary output of the device.

                                            // it is unique and must be present. it is opened by

                                            // default and receives routing, audio mode and

                                            // volume controls related to voice calls.

} audio_policy_output_flags_t;

/* device categories used for audio_policy->set_force_use() */