杭州市做网站,wordpress站点标题是什么,网站做网站反向代理违法,提供网站制作价格本课对应源文件下载链接#xff1a;
https://download.csdn.net/download/XiBuQiuChong/88680079
FFmpeg作为一套庞大的音视频处理开源工具#xff0c;其源码有太多值得研究的地方。但对于大多数初学者而言#xff0c;如何快速利用相关的API写出自己想要的东西才是迫切需要…本课对应源文件下载链接
https://download.csdn.net/download/XiBuQiuChong/88680079
FFmpeg作为一套庞大的音视频处理开源工具其源码有太多值得研究的地方。但对于大多数初学者而言如何快速利用相关的API写出自己想要的东西才是迫切需要的至于原理的进一步学习那是以后的事情。
在上一课中我们已经成功获取到视频流并显示这节课我们将参考视频的工作流程来获取音频并播放。
1.与处理视频的过程差不多要播放音频就要先初始化音频解码器在函数runFFmpeg中加入以下代码
//音频解码器
int audioIndex -1;
AVCodec *aDecodec;
AVCodecContext *aDecodeCtx NULL;//初始化并打开音频解码器
aDecodec avcodec_find_decoder(inFormatCtx-streams[audioIndex]-codecpar-codec_id);
aDecodeCtx avcodec_alloc_context3(aDecodec);
avcodec_parameters_to_context(aDecodeCtx, inFormatCtx-streams[audioIndex]-codecpar);
avcodec_open2(aDecodeCtx, aDecodec, 0);
2.在处理视频数据包后我们可以接着处理音频数据包并把音频帧转换为pcm数组加入音频队列备用
if (normalPkt.stream_index videoIndex){ret avcodec_send_packet(vDecodeCtx, normalPkt);ret avcodec_receive_frame(vDecodeCtx, deVideoFrame);av_packet_unref(normalPkt);ret sws_scale(bgrSwsCtx, (const uint8_t* const*)deVideoFrame-data, deVideoFrame-linesize, 0, deVideoFrame-height, bgrFrame.data, bgrFrame.linesize);srcMat cv::Mat(bgrFrame.height, bgrFrame.width, CV_8UC3, bgrFrame.data[0]);//imshow(viceo, srcMat);//cv::waitKey(10);mainDlg-drawMatOfPlay(srcMat);av_frame_unref(deVideoFrame);}else if (normalPkt.stream_index audioIndex){ret avcodec_send_packet(aDecodeCtx, normalPkt);while (1){ret avcodec_receive_frame(aDecodeCtx, deAudioFrame);if (ret ! 0){break;}else{int originAudioDataSize deAudioFrame-linesize[0] * deAudioFrame-channels 1;outAudioBuff new char[originAudioDataSize];int outSampleNum convertAudioFrameToAudioBuff(deAudioFrame, outAudioBuff, originAudioDataSize);int finalAudioDataSize outSampleNum *av_get_bytes_per_sample(AV_SAMPLE_FMT_S16) *deAudioFrame-channels;tmpAudioQueObj.audioDataArr outAudioBuff;tmpAudioQueObj.audioDataSize finalAudioDataSize;EnterCriticalSection(queLock);outAudioQue.push(tmpAudioQueObj);if (outAudioQue.size() 50){free(outAudioQue.front().audioDataArr);outAudioQue.front().audioDataSize 0;outAudioQue.front().audioDataArr NULL;outAudioQue.front().audioDataSize NULL;outAudioQue.pop();}LeaveCriticalSection(queLock);}av_frame_unref(deAudioFrame);}av_packet_unref(normalPkt);}
3.为了能播放声音需要先打开扬声器然后把队列中的数据送入扬声器
//打开扬声器
void fmlp::openSpeaker(){outWaveform.wFormatTag WAVE_FORMAT_PCM;outWaveform.nSamplesPerSec 44100;outWaveform.wBitsPerSample 16;outWaveform.nChannels 2;//waveform.nBlockAlign (waveform.wBitsPerSample * waveform.nChannels) / 8;outWaveform.nBlockAlign (outWaveform.wBitsPerSample*outWaveform.nChannels) 3;outWaveform.nAvgBytesPerSec outWaveform.nBlockAlign * outWaveform.nSamplesPerSec;outWaveform.cbSize 0;waveOutOpen(hWaveOut, WAVE_MAPPER, outWaveform, (DWORD)(speakerCallback), 0L, CALLBACK_FUNCTION);waveOutSetVolume(hWaveOut, 4 * 0xffffffff);waveHdrArr new WAVEHDR[audioDataArrNum];for (int i 0; i audioDataArrNum; i){waveHdrArr[i].lpData new char[finalAudioDataSize];waveHdrArr[i].dwBufferLength finalAudioDataSize;waveHdrArr[i].dwBytesRecorded 0;waveHdrArr[i].dwUser 0;waveHdrArr[i].dwFlags 0;waveHdrArr[i].dwLoops 0;waveHdrArr[i].lpNext NULL;waveHdrArr[i].reserved 0;waveOutPrepareHeader(hWaveOut, waveHdrArr[i], sizeof(WAVEHDR));}}
//扬声器回调函数
DWORD CALLBACK fmlp::speakerCallback(HWAVEOUT hwaveout, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2)
{switch (uMsg){case WOM_OPEN:break;case WOM_DONE:{LPWAVEHDR pwh (LPWAVEHDR)dwParam1;if (pwh-lpData){free(pwh-lpData);pwh-dwBufferLength 0;pwh-lpData NULL;pwh-dwBufferLength NULL;}}break;case WOM_CLOSE:break;default:break;}return 0;
}//播放声音
DWORD WINAPI fmlp::playAudioThreadProc(LPVOID lpParam){fmlp *pThis (fmlp*)lpParam;pThis-playAudio();return 0;}int fmlp::playAudio(){int i 0;while (true){if (outAudioQue.empty()){Sleep(5);continue;}EnterCriticalSection(queLock);if (waveHdrArr[i].dwFlags WHDR_PREPARED){waveHdrArr[i].lpData (LPSTR)outAudioQue.front().audioDataArr;waveHdrArr[i].dwBufferLength outAudioQue.front().audioDataSize;waveOutWrite(hWaveOut, waveHdrArr[i], sizeof(WAVEHDR));outAudioQue.pop();i;}LeaveCriticalSection(queLock);if (i audioDataArrNum){i 0;}Sleep(5);}}
4.这样一个最简单的既能播放视频也能播放音频的播放器就完成了。
