Android下音频的测试程序tinyalsa(录音，放音，查看声卡信息)

/*对pcm设备节点的操作*/

structpcm*pcm_open(unsignedintcard,unsignedintdevice,unsignedintflags,structpcm_config*config);

intpcm_close(structpcm*pcm);

intpcm_is_ready(structpcm*pcm);

/*获取pcm设备的能力*/

structpcm_params*pcm_params_get(unsignedintcard,unsignedintdevice,unsignedintflags);

voidpcm_params_free(structpcm_params*pcm_params);

unsignedintpcm_params_get_min(structpcm_params*pcm_params,enumpcm_paramparam);

unsignedintpcm_params_get_max(structpcm_params*pcm_params,enumpcm_paramparam);

/*配置pcm设备capture和playback的规格*/

intpcm_get_config(structpcm*pcm,structpcm_config*config);

intpcm_set_config(structpcm*pcm,structpcm_config*config);

/*返回调用tinyalsa最后的错误信息*/

constchar*pcm_get_error(structpcm*pcm);

/*设置pcm设备采集和播放的位数，位数越高越接近真实声音*/

unsignedintpcm_format_to_bits(enumpcm_formatformat);

/*pcm设备的内置缓冲之间大小、帧数、时间的转换*/

unsignedintpcm_get_buffer_size(structpcm*pcm);

unsignedintpcm_frames_to_bytes(structpcm*pcm,unsignedintframes);

unsignedintpcm_bytes_to_frames(structpcm*pcm,unsignedintbytes);

unsignedintpcm_get_latency(structpcm*pcm);//inms

/*返回下一帧的有效帧指针和该帧时间戳，时间戳有CLOCK_MONOTONIC和CLOCK_REALTIME可选，里面使用的是CLOCK_REALTIME*/

/*我认为应该需要两个时间戳，一个用于播放的时间戳（CLOCK_MONOTONIC）不受系统时间的影响，一个用于记录当前音频采集的时间戳（CLOCK_REALTIME）*/

intpcm_get_htimestamp(structpcm*pcm,unsignedint*avail,structtimespec*tstamp);

/*通过FIFO把数据写入硬件用于playback或者从硬件中读取capture数据*/

intpcm_write(structpcm*pcm,constvoid*data,unsignedintcount);

intpcm_read(structpcm*pcm,void*data,unsignedintcount);

/*这是一个可选的和hardware通信的方式。*/

intpcm_mmap_write(structpcm*pcm,constvoid*data,unsignedintcount);

intpcm_mmap_read(structpcm*pcm,void*data,unsignedintcount);

intpcm_mmap_begin(structpcm*pcm,void**areas,unsignedint*offset,unsignedint*frames);

intpcm_mmap_commit(structpcm*pcm,unsignedintoffset,unsignedintframes);

intpcm_start(structpcm*pcm);

intpcm_stop(structpcm*pcm);

intpcm_wait(structpcm*pcm,inttimeout);

intpcm_set_avail_min(structpcm*pcm,intavail_min);

/*对mixer设备的操作*/

structmixer*mixer_open(unsignedintcard);

voidmixer_close(structmixer*mixer);

/*获取mixer设备信息name*/

constchar*mixer_get_name(structmixer*mixer);

/*获取mixer设备的控制句柄structmixer_ctl*/

unsignedintmixer_get_num_ctls(structmixer*mixer);

structmixer_ctl*mixer_get_ctl(structmixer*mixer,unsignedintid);

structmixer_ctl*mixer_get_ctl_by_name(structmixer*mixer,constchar*name);

/*取mixer设备的控制信息*/

constchar*mixer_ctl_get_name(structmixer_ctl*ctl);

enummixer_ctl_typemixer_ctl_get_type(structmixer_ctl*ctl);

constchar*mixer_ctl_get_type_string(structmixer_ctl*ctl);

unsignedintmixer_ctl_get_num_values(structmixer_ctl*ctl);

unsignedintmixer_ctl_get_num_enums(structmixer_ctl*ctl);

constchar*mixer_ctl_get_enum_string(structmixer_ctl*ctl,unsignedintenum_id);

/*Somesoundcardsupdatetheircontrolsduetoexternalevents,

*suchasHDMIEDIDbytedatachangingwhenanHDMIcableis

*connected.ThisAPIallowsthecountofelementstobeupdated.

*/

voidmixer_ctl_update(structmixer_ctl*ctl);

/*设置和获取可控制的信息，方式有比例、数组、范围、固定值*/

/*id通过mixer_get_num_ctls获得*/

intmixer_ctl_get_percent(structmixer_ctl*ctl,unsignedintid);

intmixer_ctl_set_percent(structmixer_ctl*ctl,unsignedintid,intpercent);

intmixer_ctl_get_value(structmixer_ctl*ctl,unsignedintid);

intmixer_ctl_get_array(structmixer_ctl*ctl,void*array,size_tcount);

intmixer_ctl_set_value(structmixer_ctl*ctl,unsignedintid,intvalue);

intmixer_ctl_set_array(structmixer_ctl*ctl,constvoid*array,size_tcount);

intmixer_ctl_set_enum_by_string(structmixer_ctl*ctl,constchar*string);

intmixer_ctl_get_range_min(structmixer_ctl*ctl);

intmixer_ctl_get_range_max(structmixer_ctl*ctl);

//原始状态

root@pone:/data/local/tmp#tinymix-D1

Mixername:'mixer_name_xx'

Numberofcontrols:2

ctl	type	num	namevalue

0	BOOL	1	MicCaptureSwitchOff

1	INT	1	MicCaptureVolume256

//详细信息

root@pone:/data/local/tmp#tinymix-D10

MicCaptureSwitch:Off

root@pone:/data/local/tmp#tinymix-D11

MicCaptureVolume:256(range0->256)

//设置

root@pone:/data/local/tmp#tinymix-D101

root@pone:/data/local/tmp#tinymix-D11250

//修改后的状态

root@pone:/data/local/tmp#tinymix-D1

Mixername:'mixer_name_xx'

Numberofcontrols:2

ctl	type	num	namevalue

0	BOOL	1	MicCaptureSwitchOn

1	INT	1	MicCaptureVolume250