iOS端 TRTC v2 版本自定义采集视频数据实现

//组装一个 TRTCVideoFrame 并将其送给 trtcCloud 对象
TRTCVideoFrame* videoFrame = [TRTCVideoFrame new];
videoFrame.bufferType = TRTCVideoBufferType_PixelBuffer;
videoFrame.pixelFormat = TRTCVideoPixelFormat_NV12;
videoFrame.pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);

[trtcCloud sendCustomVideoData:videoFrame];

// 启用视频自定义采集模式
[_trtc enableCustomVideoCapture:YES];

// 打开 SDK 音频采集（自定义采集场景下不需要打开 SDK 本地预览）
// [_trtc startLocalPreview:YES view:_localView];
[_trtc startLocalAudio];

// 进房
TRTCAppScene scene = [TRTCSettingViewController getAppScene];
[_trtc enterRoom:self.param appScene:scene];

#pragma mark - AVCaptureVideoDataAndAudioDataOutputSampleBufferDelegate
//以系统API调用 AVCaptureSession 采集 NV12 格式数据为例
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {

    TRTCVideoFrame* videoFrame = [TRTCVideoFrame new];
    videoFrame.bufferType = TRTCVideoBufferType_PixelBuffer;
    videoFrame.pixelFormat = TRTCVideoPixelFormat_NV12;
    videoFrame.pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    [_trtc sendCustomVideoData:videoFrame];

}

//通过 libyuv 转换 yuv 格式
- (void)nv12ToI420:(CVPixelBufferRef)src dest:(CVPixelBufferRef)dst {

    //图像宽度（像素）
    int pixelWidth = (int)CVPixelBufferGetWidth(src);
    //图像高度（像素）
    int pixelHeight = (int)CVPixelBufferGetHeight(src);

    uint8_t *src_y = NULL;
    uint8_t *src_uv = NULL;
    uint8_t *dst_y = NULL;
    uint8_t *dst_u = NULL;
    uint8_t *dst_v = NULL;
    CVPixelBufferLockBaseAddress(src, 0);
    src_y = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(src, 0);
    src_uv = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(src, 1);
    int src_ystride = (int)CVPixelBufferGetBytesPerRowOfPlane(src, 0);
    int src_uvstride = (int)CVPixelBufferGetBytesPerRowOfPlane(src, 1);
    CVPixelBufferLockBaseAddress(dst, 0);
    dst_y = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(dst, 0);
    dst_u = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(dst, 1);
    dst_v = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(dst, 2);
    int dst_ystride = (int)CVPixelBufferGetBytesPerRowOfPlane(dst, 0);
    int dst_ustride = (int)CVPixelBufferGetBytesPerRowOfPlane(dst, 1);
    int dst_vstride = (int)CVPixelBufferGetBytesPerRowOfPlane(dst, 2);

    NV12ToI420(src_y, src_ystride, src_uv, src_uvstride, dst_y, dst_ystride, dst_u, dst_ustride, dst_v, dst_vstride, pixelWidth, pixelHeight);

    CVPixelBufferUnlockBaseAddress(src, 0);
    CVPixelBufferUnlockBaseAddress(dst, 0);
}