Enable audio transmission

2026-04-02 15:35:30 +08:00 · 2023-11-29 22:04:53 -08:00
parent 733434f9b3
commit 4a65a59803
12 changed files with 1520 additions and 271 deletions
--- a/test/audio_capture/windows_capture.cpp
+++ b/test/audio_capture/windows_capture.cpp
@@ -0,0 +1,123 @@
+#define __STDC_CONSTANT_MACROS
+extern "C" {
+#include <libavdevice/avdevice.h>
+#include <libavformat/avformat.h>
+#include <libavutil/log.h>
+#include <libswresample/swresample.h>
+}
+
+#include <windows.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#pragma comment(lib, "avutil.lib")
+#pragma comment(lib, "avdevice.lib")
+#pragma comment(lib, "avformat.lib")
+#pragma comment(lib, "avcodec.lib")
+
+#pragma comment(lib, "Winmm.lib")
+
+using std::shared_ptr;
+using std::string;
+using std::vector;
+
+void capture_audio() {
+  // windows api 获取音频设备列表（ffmpeg 好像没有提供获取音视频设备的api）
+  int nDeviceNum = waveInGetNumDevs();
+  vector<string> vecDeviceName;
+  for (int i = 0; i < nDeviceNum; ++i) {
+    WAVEINCAPS wic;
+    waveInGetDevCaps(i, &wic, sizeof(wic));
+
+    // 转成utf-8
+    int nSize = WideCharToMultiByte(CP_UTF8, 0, wic.szPname,
+                                    wcslen(wic.szPname), NULL, 0, NULL, NULL);
+    shared_ptr<char> spDeviceName(new char[nSize + 1]);
+    memset(spDeviceName.get(), 0, nSize + 1);
+    WideCharToMultiByte(CP_UTF8, 0, wic.szPname, wcslen(wic.szPname),
+                        spDeviceName.get(), nSize, NULL, NULL);
+    vecDeviceName.push_back(spDeviceName.get());
+    av_log(NULL, AV_LOG_DEBUG, "audio input device : %s \n",
+           spDeviceName.get());
+  }
+  if (vecDeviceName.size() <= 0) {
+    av_log(NULL, AV_LOG_ERROR, "not find audio input device.\n");
+    return;
+  }
+  string sDeviceName = "audio=" + vecDeviceName[0];  // 使用第一个音频设备
+
+  // ffmpeg
+  avdevice_register_all();  // 注册所有输入输出设备
+  AVInputFormat* ifmt =
+      (AVInputFormat*)av_find_input_format("dshow");  // 设置采集方式 dshow
+  if (ifmt == NULL) {
+    av_log(NULL, AV_LOG_ERROR, "av_find_input_format for dshow fail.\n");
+    return;
+  }
+
+  AVFormatContext* fmt_ctx = NULL;  // format 上下文
+  int ret = avformat_open_input(&fmt_ctx, sDeviceName.c_str(), ifmt,
+                                NULL);  // 打开音频设备
+  if (ret != 0) {
+    av_log(NULL, AV_LOG_ERROR, "avformat_open_input fail. return %d.\n", ret);
+    return;
+  }
+
+  AVPacket pkt;
+
+  int64_t src_rate = 44100;
+  int64_t dst_rate = 48000;
+  SwrContext* swr_ctx = swr_alloc();
+
+  uint8_t** dst_data = NULL;
+  int dst_linesize = 0;
+
+  // 设置输入参数
+  av_opt_set_int(swr_ctx, "in_channel_layout", AV_CH_LAYOUT_MONO, 0);
+  av_opt_set_int(swr_ctx, "in_sample_rate", src_rate, 0);
+  av_opt_set_sample_fmt(swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
+  // 设置输出参数
+  av_opt_set_int(swr_ctx, "out_channel_layout", AV_CH_LAYOUT_STEREO, 0);
+  av_opt_set_int(swr_ctx, "out_sample_rate", dst_rate, 0);
+  av_opt_set_sample_fmt(swr_ctx, "out_sample_fmt", AV_SAMPLE_FMT_S16, 0);
+  // 初始化SwrContext
+  swr_init(swr_ctx);
+
+  FILE* fp = fopen("dst.pcm", "wb");
+  int count = 0;
+  while (count++ < 10) {
+    ret = av_read_frame(fmt_ctx, &pkt);
+    if (ret != 0) {
+      av_log(NULL, AV_LOG_ERROR, "av_read_frame fail, return %d .\n", ret);
+      break;
+    }
+
+    int out_samples_per_channel =
+        (int)av_rescale_rnd(1024, dst_rate, src_rate, AV_ROUND_UP);
+    int out_buffer_size = av_samples_get_buffer_size(
+        NULL, 1, out_samples_per_channel, AV_SAMPLE_FMT_S16, 0);
+    // uint8_t* out_buffer = (uint8_t*)av_malloc(out_buffer_size);
+    ret = av_samples_alloc_array_and_samples(
+        &dst_data, &dst_linesize, 2, out_buffer_size, AV_SAMPLE_FMT_S16, 0);
+
+    // 进行重采样
+    swr_convert(swr_ctx, dst_data, out_samples_per_channel,
+                (const uint8_t**)&pkt.data, 1024);
+
+    fwrite(dst_data[1], 1, out_buffer_size, fp);
+    av_packet_unref(&pkt);  // 必须释放pkt申请的内存，否则会内存泄露
+  }
+  fflush(fp);  // 刷新文件io输出缓冲区
+  fclose(fp);
+
+  avformat_close_input(&fmt_ctx);
+}
+
+int main(int argc, char** argv) {
+  av_log_set_level(AV_LOG_DEBUG);  // 设置ffmpeg日志库等级
+  capture_audio();
+
+  Sleep(1);
+}