Merge "aaudio: Update aaudio_loopback usage screen"

}

static void usage() {

    printf("loopback: -n{numBursts} -p{outPerf} -P{inPerf} -t{test} -g{gain} -f{freq}\n");

    printf("          -c{inputChannels}\n");

    printf("          -f{freq}  sine frequency\n");

    printf("Usage: aaudio_loopback [OPTION]...\n\n");

    printf("          -c{inputChannels} number of input channels\n");

    printf("          -g{gain}          recirculating loopback gain\n");

    printf("          -m                enable MMAP mode\n");

    printf("          -n{numBursts}     buffer size, for example 2 for double buffered\n");

    printf("          -P{inPerf}        set input AAUDIO_PERFORMANCE_MODE*\n");

    printf("              n for _NONE\n");

    printf("              l for _LATENCY\n");

    printf("              p for _POWER_SAVING;\n");

    printf("              p for _POWER_SAVING\n");

    printf("          -t{test}          select test mode\n");

    printf("              m for sine magnitude\n");

    printf("              e for echo latency (default)\n");

    printf("For example:  loopback -b2 -pl -Pn\n");

    printf("              e for echo latency (default)\n\n");

    printf("Example:  aaudio_loopback -n2 -pl -Pn\n");

}

static aaudio_performance_mode_t parsePerformanceMode(char c) {