命令行方式采集

ffmpeg在windows下查看设备的命令：
ffmpeg -list_devices true -f dshow -i dummy
音频采集：

  1. ffmpeg -f dshow -i audio="麦克风 (Realtek(R) Audio)" out.mp3
  2. ffmpeg -f dshow -i audio="麦克风 (Realtek(R) Audio)" -acodec aac out.aac
  3. ffmpeg -f dshow -i audio="麦克风 (Realtek(R) Audio)" -ar 16000 -ac 1 out.wav

ffplay播放yuv：

  1. ffplay -i F:\virtual-code\yuv_encode.c\video.yuv -pix_fmt yuv420p  -s 1280x720

调用ffmpeg接口采集

  1. //采集windows下的麦克风数据, 并保存pcm文件
  2. //需要注意的两个点：
  3. //1、给avformat_open_input传入设备文件名时对文件名的格式有要求，故做了文件名的字符格式转换
  4. //2、采集设备下的音频数据时，设置采样参数无效，猜测是每个设备会有自己固定的采样参数
  5. #include <iostream>
  6. #include <strsafe.h>
  8. #define __STDC_CONSTANT_MACROS
  10. extern "C"
  11. {
  12. #include "libavutil/avutil.h"
  13. #include "libavdevice/avdevice.h"
  14. #include "libswscale/swscale.h"
  15. #include "libswresample/swresample.h"
  16. #include <stdio.h>
  17. }
  19. #ifdef _MSC_VER
  20. #include <tchar.h>
  21. #include <dshow.h>
  22. #include <atlcomcli.h>
  23. #pragma comment(lib, "Strmiids.lib")
  24. #endif
  26. void Convert(const char* strIn, char* strOut, int sourceCodepage, int targetCodepage)
  27. {
  28.     //LPCTSTR
  29.     LPCTSTR pStr = (LPCTSTR)strIn;
  30.     int len = lstrlen(pStr);
  31.     int unicodeLen = MultiByteToWideChar(sourceCodepage, 0, strIn, -1, NULL, 0);
  32.     wchar_t* pUnicode = NULL;
  33.     pUnicode = new wchar_t[unicodeLen + 1];
  34.     memset(pUnicode, 0, (unicodeLen + 1) * sizeof(wchar_t));
  35.     MultiByteToWideChar(sourceCodepage, 0, strIn, -1, (LPWSTR)pUnicode, unicodeLen);
  37.     BYTE* pTargetData = NULL;
  38.     int targetLen = WideCharToMultiByte(targetCodepage, 0, (LPWSTR)pUnicode, -1, (char*)pTargetData, 0, NULL, NULL);
  40.     pTargetData = new BYTE[targetLen + 1];
  41.     memset(pTargetData, 0, targetLen + 1);
  42.     WideCharToMultiByte(targetCodepage, 0, (LPWSTR)pUnicode, -1, (char*)pTargetData, targetLen, NULL, NULL);
  43.     lstrcpy((LPSTR)strOut, (LPCSTR)pTargetData);
  45.     delete pUnicode;
  46.     delete pTargetData;
  47. }
  49. void Get_Capture_Audio_Devices_Info(char* name)
  50. {
  52. #ifdef _MSC_VER
  53.     CoInitialize(NULL);
  54.     CComPtr<ICreateDevEnum> pCreateDevEnum;
  55.     HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, (void**)&pCreateDevEnum);
  56.     CComPtr<IEnumMoniker> pEm;
  57.     hr = pCreateDevEnum->CreateClassEnumerator(CLSID_AudioInputDeviceCategory, &pEm, 0);
  58.     if (hr != NOERROR) {
  59.         return;
  60.     }
  61.     pEm->Reset();
  62.     ULONG cFetched;
  63.     IMoniker* pM = NULL;
  64.     while (hr = pEm->Next(1, &pM, &cFetched), hr == S_OK)
  65.     {
  66.         IPropertyBag* pBag = 0;
  67.         hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void**)&pBag);
  68.         if (SUCCEEDED(hr))
  69.         {
  70.             VARIANT var;
  71.             var.vt = VT_BSTR;
  72.             hr = pBag->Read(L"FriendlyName", &var, NULL); //还有其他属性,像描述信息等等...
  73.             if (hr == NOERROR)
  74.             {
  75.                 char str[128];
  76.                 //获取设备名称
  77.                 WideCharToMultiByte(CP_ACP, 0, var.bstrVal, -1, name, 128, "", NULL);
  78.                 SysFreeString(var.bstrVal);
  79.             }
  80.             pBag->Release();
  81.         }
  82.         pM->Release();
  83.     }
  85.     pCreateDevEnum = NULL;
  86.     pEm = NULL;
  87. #else
  88.     memcpy(name, "default", strlen("default") + 1);
  89. #endif
  91. }
  93. int main() 
  94. {
  95.     int ret = 0;
  97.     AVFormatContext* fmt_ctx = NULL;
  98.     AVDictionary* options = NULL;
  100.     char errors[1024] = { 0 };
  101.     char device_name[256] = { 0 };
  102.     char file_name[256] = "collection.pcm";
  103.     char name[128] = { 0 };
  104.     char name_utf8[128] = { 0 };
  106.     //设置输入的字体，没有这部分会报错 //Immediate exit requested
  107.     Get_Capture_Audio_Devices_Info(name);
  108.     Convert(name, name_utf8, CP_ACP, CP_UTF8);
  109.     sprintf(device_name, "audio=%s", name_utf8);
  110.     printf("device_name:%s\n", device_name);
  112.     av_register_all();
  113.     avdevice_register_all();
  114. #if 0 //这里设置采样参数无效 我电脑上的采样参数为 双通道 采样率-44100 采样位数-s16le
  115.     //ffplay 播放音频命令 ffplay -ar 44100 -f s16le -channels 2 -i collection.pcm
  116.     char option_key[] = "ar";
  117.     char option_value[] = "44100";
  118.     av_dict_set(&options, option_key, option_value, 0);
  119.     char option_key1[] = "ac";
  120.     char option_value1[] = "2";
  121.     av_dict_set(&options, option_key1, option_value1, 0);
  122. #endif
  124.     AVInputFormat* in_format = av_find_input_format("dshow");
  125.     if (in_format == NULL)
  126.     {
  127.         printf("av_find_input_format error\n");
  128.     }
  129.     //return 0;
  130.     //fmt_ctx = avformat_alloc_context();
  131.     if ((ret = avformat_open_input(&fmt_ctx, device_name, in_format, NULL)) != 0)
  132.     //if ((ret = avformat_open_input(&fmt_ctx, device_name, in_format, &options)) != 0)
  133.     {
  134.         av_strerror(ret, errors, 1024);
  135.         printf("Failed to open audio device, [%s][%d]\n", errors, ret);
  136.         return -1;
  137.     }
  140.     AVPacket* pkt = av_packet_alloc();
  141.     av_init_packet(pkt);
  142.     FILE* out_file = fopen(file_name, "wb+");
  145.     while (!av_read_frame(fmt_ctx, pkt)) 
  146.     {
  147.         printf("Size of collected data %d\n", pkt->size);
  149.         fwrite(pkt->data, 1, pkt->size, out_file);
  150.         fflush(out_file);
  151.         av_packet_unref(pkt);
  152.     }
  154.     av_packet_free(&pkt);
  155.     avformat_close_input(&fmt_ctx);
  156.     //avformat_free_context(fmt_ctx);
  157.     fclose(out_file);
  159.     return 0;
  160. }

```