轉自：http://blog.csdn.net/nonmarking/article/details/47958395

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本系列目前共三篇文章，后續還會更新

WebRTC VideoEngine超詳細教程（一）——視頻通話的基本流程

WebRTC VideoEngine超詳細教程（二）——集成OPENH264編解碼器

WebRTC VideoEngine超詳細教程（三）——集成X264編碼和ffmpeg解碼

總述

在前一篇文章中，講解了如何將OPENH264編解碼器集成到WebRTC中，但是OPENH264只能編碼baseline的H264視頻，而且就編碼質量而言，還是X264最好，本文就來講解一下如何將X264編碼器集成到WebRTC中，為了實現解碼，同時要用到ffmpeg。總體流程和之前一樣，分為重新封裝編解碼器和注冊調用兩大步驟，注冊調用這一步沒有任何不同，主要是重新封裝這一步驟有較大區別。

重新封裝X264編碼功能

首先當然還是要下載X264源碼編譯出相應的庫以供調用。在windows下使用mingw進行編譯，再使用poxports工具導出庫，最后得到libx264.dll和libx264.lib，同時把x264.h和x264_config.h總共四個文件放到工程目錄下，并在項目屬性中進行相應配置。 使用x264進行視頻編碼的基本流程如下 [cpp]?view plaincopy

#include?<stdint.h>??

#include?<stdio.h>??

#include?<x264.h>??

??

int?main(?int?argc,?char?**argv?)??

{??

????int?width,?height;??

????x264_param_t?param;??

????x264_picture_t?pic;??

????x264_picture_t?pic_out;??

????x264_t?*h;??

????int?i_frame?=?0;??

????int?i_frame_size;??

????x264_nal_t?*nal;??

????int?i_nal;??

??

????/*?Get?default?params?for?preset/tuning?*/??

????if(?x264_param_default_preset(?&param,?"medium",?NULL?)?<?0?)??

????????goto?fail;??

??

????/*?Configure?non-default?params?*/??

????param.i_csp?=?X264_CSP_I420;??

????param.i_width??=?width;??

????param.i_height?=?height;??

????param.b_vfr_input?=?0;??

????param.b_repeat_headers?=?1;??

????param.b_annexb?=?1;??

??

????/*?Apply?profile?restrictions.?*/??

????if(?x264_param_apply_profile(?&param,?"high"?)?<?0?)??

????????goto?fail;??

??

????if(?x264_picture_alloc(?&pic,?param.i_csp,?param.i_width,?param.i_height?)?<?0?)??

????????goto?fail;??

??

????h?=?x264_encoder_open(?&param);??

????if(?!h?)??

????????goto?fail;??

??

????int?luma_size?=?width?*?height;??

????int?chroma_size?=?luma_size?/?4;??

????/*?Encode?frames?*/??

????for(?;;?i_frame++?)??

????{??

????????/*?Read?input?frame?*/??

????????if(?fread(?pic.img.plane[0],?1,?luma_size,?stdin?)?!=?luma_size?)??

????????????break;??

????????if(?fread(?pic.img.plane[1],?1,?chroma_size,?stdin?)?!=?chroma_size?)??

????????????break;??

????????if(?fread(?pic.img.plane[2],?1,?chroma_size,?stdin?)?!=?chroma_size?)??

????????????break;??

??

????????pic.i_pts?=?i_frame;??

????????i_frame_size?=?x264_encoder_encode(?h,?&nal,?&i_nal,?&pic,?&pic_out?);??

????????if(?i_frame_size?<?0?)??

????????????goto?fail;??

????????else?if(?i_frame_size?)??

????????{??

????????????if(?!fwrite(?nal->p_payload,?i_frame_size,?1,?stdout?)?)??

????????????????goto?fail;??

????????}??

????}??

????/*?Flush?delayed?frames?*/??

????while(?x264_encoder_delayed_frames(?h?)?)??

????{??

????????i_frame_size?=?x264_encoder_encode(?h,?&nal,?&i_nal,?NULL,?&pic_out?);??

????????if(?i_frame_size?<?0?)??

????????????goto?fail;??

????????else?if(?i_frame_size?)??

????????{??

????????????if(?!fwrite(?nal->p_payload,?i_frame_size,?1,?stdout?)?)??

????????????????goto?fail;??

????????}??

????}??

??

????x264_encoder_close(?h?);??

????x264_picture_clean(?&pic?);??

????return?0;??

}??

還是一樣，照葫蘆畫瓢，改寫上一篇文章中提到的H264EncoderImpl類 首先是類的定義，去掉了原來的私有成員變量ISVCEncoder* encoder_，加入了以下幾項，其他內容不變 [cpp]?view plaincopy

x264_picture_t?pic;??

x264_picture_t?pic_out;??

x264_t?*encoder_;??

int?i_frame?=?0;//frame?index??

x264_nal_t?*nal;??

相應的，構造函數和析構函數也要改變，這里就不贅述了，重點看InitEncode方法和Encode方法。 InitEncode方法的實現改寫如下 [cpp]?view plaincopy

int?H264EncoderImpl::InitEncode(const?VideoCodec*?inst,??

????????int?number_of_cores,??

????????size_t?max_payload_size)?{??

????????if?(inst?==?NULL)?{??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

????????if?(inst->maxFramerate?<?1)?{??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

????????//?allow?zero?to?represent?an?unspecified?maxBitRate??

????????if?(inst->maxBitrate?>?0?&&?inst->startBitrate?>?inst->maxBitrate)?{??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

????????if?(inst->width?<?1?||?inst->height?<?1)?{??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

????????if?(number_of_cores?<?1)?{??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

??

????????int?ret_val?=?Release();??

????????if?(ret_val?<?0)?{??

????????????return?ret_val;??

????????}??

????????/*?Get?default?params?for?preset/tuning?*/??

????????x264_param_t?param;??

????????ret_val?=?x264_param_default_preset(&param,?"medium",?NULL);??

????????if?(ret_val?!=?0)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::InitEncode()?fails?to?initialize?encoder?ret_val?%d",??

????????????????ret_val);??

????????????x264_encoder_close(encoder_);??

????????????encoder_?=?NULL;??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

????????/*?Configure?non-default?params?*/??

????????param.i_csp?=?X264_CSP_I420;??

????????param.i_width?=?inst->width;??

????????param.i_height?=?inst->height;??

????????param.b_vfr_input?=?0;??

????????param.b_repeat_headers?=?1;??

????????param.b_annexb?=?0;//這里設置為0，是為了使編碼后的NAL統一有4字節的起始碼，便于處理，否則會同時有3字節和4字節的起始碼，很麻煩??

????????param.i_fps_num?=?1;??

????????param.i_fps_num?=?codec_.maxFramerate;??

????????param.rc.i_bitrate?=?codec_.maxBitrate;??

????????/*?Apply?profile?restrictions.?*/??

????????ret_val?=?x264_param_apply_profile(&param,?"high");??

????????if?(ret_val?!=?0)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::InitEncode()?fails?to?initialize?encoder?ret_val?%d",??

????????????????ret_val);??

????????????x264_encoder_close(encoder_);??

????????????encoder_?=?NULL;??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

??

????????ret_val?=?x264_picture_alloc(&pic,?param.i_csp,?param.i_width,?param.i_height);??

????????if?(ret_val?!=?0)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::InitEncode()?fails?to?initialize?encoder?ret_val?%d",??

????????????????ret_val);??

????????????x264_encoder_close(encoder_);??

????????????encoder_?=?NULL;??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

??

????????encoder_?=?x264_encoder_open(&param);??

????????if?(!encoder_){??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::InitEncode()?fails?to?initialize?encoder?ret_val?%d",??

????????????????ret_val);??

????????????x264_encoder_close(encoder_);??

????????????x264_picture_clean(&pic);??

????????????encoder_?=?NULL;??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

??

????????if?(&codec_?!=?inst)?{??

????????????codec_?=?*inst;??

????????}??

??

????????if?(encoded_image_._buffer?!=?NULL)?{??

????????????delete[]?encoded_image_._buffer;??

????????}??

????????encoded_image_._size?=?CalcBufferSize(kI420,?codec_.width,?codec_.height);??

????????encoded_image_._buffer?=?new?uint8_t[encoded_image_._size];??

????????encoded_image_._completeFrame?=?true;??

??

????????inited_?=?true;??

????????WEBRTC_TRACE(webrtc::kTraceApiCall,?webrtc::kTraceVideoCoding,?-1,??

????????????"H264EncoderImpl::InitEncode(width:%d,?height:%d,?framerate:%d,?start_bitrate:%d,?max_bitrate:%d)",??

????????????inst->width,?inst->height,?inst->maxFramerate,?inst->startBitrate,?inst->maxBitrate);??

??

????????return?WEBRTC_VIDEO_CODEC_OK;??

????}??

Encode方法的實現改寫如下 [cpp]?view plaincopy

int?H264EncoderImpl::Encode(const?I420VideoFrame&?input_image,??

????????const?CodecSpecificInfo*?codec_specific_info,??

????????const?std::vector<VideoFrameType>*?frame_types)?{??

????????if?(!inited_)?{??

????????????return?WEBRTC_VIDEO_CODEC_UNINITIALIZED;??

????????}??

????????if?(input_image.IsZeroSize())?{??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

????????if?(encoded_complete_callback_?==?NULL)?{??

????????????return?WEBRTC_VIDEO_CODEC_UNINITIALIZED;??

????????}??

??

????????VideoFrameType?frame_type?=?kDeltaFrame;??

????????//?We?only?support?one?stream?at?the?moment.??

????????if?(frame_types?&&?frame_types->size()?>?0)?{??

????????????frame_type?=?(*frame_types)[0];??

????????}??

??

????????bool?send_keyframe?=?(frame_type?==?kKeyFrame);??

????????if?(send_keyframe)?{??

????????????pic.b_keyframe?=?TRUE;??

????????????WEBRTC_TRACE(webrtc::kTraceApiCall,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::EncodeKeyFrame(width:%d,?height:%d)",??

????????????????input_image.width(),?input_image.height());??

????????}??

??

????????//?Check?for?change?in?frame?size.??

????????if?(input_image.width()?!=?codec_.width?||??

????????????input_image.height()?!=?codec_.height)?{??

????????????int?ret?=?UpdateCodecFrameSize(input_image);??

????????????if?(ret?<?0)?{??

????????????????return?ret;??

????????????}??

????????}??

??

????????/*?Read?input?frame?*/??

????????pic.img.plane[0]?=?const_cast<uint8_t*>(input_image.buffer(kYPlane));??

????????pic.img.plane[1]?=?const_cast<uint8_t*>(input_image.buffer(kUPlane));??

????????pic.img.plane[2]?=?const_cast<uint8_t*>(input_image.buffer(kVPlane));??

????????pic.i_pts?=?i_frame;??

??

????????int?i_nal?=?0;??

????????int?i_frame_size?=?x264_encoder_encode(encoder_,?&nal,?&i_nal,?&pic,?&pic_out);??

????????if?(i_frame_size?<?0)??

????????{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::Encode()?fails?to?encode?%d",??

????????????????i_frame_size);??

????????????x264_encoder_close(encoder_);??

????????????x264_picture_clean(&pic);??

????????????encoder_?=?NULL;??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

??

????????RTPFragmentationHeader?frag_info;??

??????????

????????if?(i_frame_size)??

????????{??

????????????if?(i_nal?==?0)?{??

????????????????return?WEBRTC_VIDEO_CODEC_OK;??

????????????}??

????????????frag_info.VerifyAndAllocateFragmentationHeader(i_nal);??

??

????????????encoded_image_._length?=?0;??

??

????????????uint32_t?totalNaluIndex?=?0;??

????????????for?(int?nal_index?=?0;?nal_index?<?i_nal;?nal_index++)??

????????????{??

????????????????uint32_t?currentNaluSize?=?0;??

????????????????currentNaluSize?=?nal[nal_index].i_payload?-?4;?//x264_encoder_encode編碼得到的nal單元是已經帶有起始碼的，此外，這里直接使用nal[index]即可，不必再使用x264_nal_encode函數??

????????????????memcpy(encoded_image_._buffer?+?encoded_image_._length,?nal[nal_index].p_payload?+?4,?currentNaluSize);//encoded_image_中存有的是去掉起始碼的數據??

????????????????encoded_image_._length?+=?currentNaluSize;??

??

????????????????WEBRTC_TRACE(webrtc::kTraceApiCall,?webrtc::kTraceVideoCoding,?-1,??

????????????????????"H264EncoderImpl::Encode()?nal_type?%d,?length:%d",??

????????????????????nal[nal_index].i_type,?encoded_image_._length);??

??

????????????????frag_info.fragmentationOffset[totalNaluIndex]?=?encoded_image_._length?-?currentNaluSize;??

????????????????frag_info.fragmentationLength[totalNaluIndex]?=?currentNaluSize;??

????????????????frag_info.fragmentationPlType[totalNaluIndex]?=?nal[nal_index].i_type;??

????????????????frag_info.fragmentationTimeDiff[totalNaluIndex]?=?0;??

????????????????totalNaluIndex++;??

????????????}??

????????}??

????????i_frame++;??

????????if?(encoded_image_._length?>?0)?{??

????????????encoded_image_._timeStamp?=?input_image.timestamp();??

????????????encoded_image_.capture_time_ms_?=?input_image.render_time_ms();??

????????????encoded_image_._encodedHeight?=?codec_.height;??

????????????encoded_image_._encodedWidth?=?codec_.width;??

????????????encoded_image_._frameType?=?frame_type;??

????????????//?call?back??

????????????encoded_complete_callback_->Encoded(encoded_image_,?NULL,?&frag_info);??

????????}??

????????return?WEBRTC_VIDEO_CODEC_OK;??

????}??

其他方法的實現均沒有改變。 至此，X264編碼器重新封裝完畢，還是比較好理解的。

重新封裝ffmpeg解碼功能

首先還是一樣，獲得ffmpeg的頭文件和庫文件，加入工程中并進行相應設置，這里只需使用avcodec avformat avutil swscale四個庫，頭文件也可以做相應的刪減。 ffmpeg解碼的基本流程如下，實際集成之后是從WebRTC的EncodedImage& input_image中獲得待解碼數據的，所以不能使用常見的基于文件的解碼流程 [cpp]?view plaincopy

AVCodec?*codec?=?avcodec_find_decoder(AV_CODEC_ID_H264);??

AVCodecContext?*codecCtx?=?avcodec_alloc_context3(codec);??

avcodec_open2(codecCtx,?codec,?nil);??

char?*videoData;??

int?len;??

AVFrame?*frame?=?av_frame_alloc();??

AVPacket?packet;??

av_new_packet(&packet,?len);??

memcpy(packet.data,?videoData,?len);??

int?ret,?got_picture;??

ret?=?avcodec_decode_video2(codecCtx,?frame,?&got_picture,?&packet);??

if?(ret?>?0){??

????if(got_picture){??

????//進行下一步的處理??

????}??

}??

相應的，對H264DecoderImpl類的定義和各方法的實現要進行改寫。
首先是類的定義，去掉了ISVCDecoder* decoder_，加入了以下私有成員變量 [cpp]?view plaincopy

AVCodecContext??*pCodecCtx;??

??AVCodec???????????*pCodec;??

??AVFrame???*pFrame,?*pFrameYUV;??

??AVPacket?*packet;??

??struct?SwsContext?*img_convert_ctx;??

??uint8_t?*decode_buffer;//存儲最開始收到的SPS、PPS和IDR幀以便進行最開始的解碼??

??uint8_t?*out_buffer;??

??int?framecnt?=?0;??

??int?encoded_length?=?0;??

構造函數和析構函數的改寫省略不表，重點看一下InitDecode方法和Decode方法 InitDecode方法改寫如下 [cpp]?view plaincopy

int?H264DecoderImpl::InitDecode(const?VideoCodec*?inst,?int?number_of_cores)?{??

????????if?(inst?==?NULL)?{??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

????????int?ret_val?=?Release();??

????????if?(ret_val?<?0)?{??

????????????return?ret_val;??

????????}??

??

????????if?(&codec_?!=?inst)?{??

????????????//?Save?VideoCodec?instance?for?later;?mainly?for?duplicating?the?decoder.??

????????????codec_?=?*inst;??

????????}??

????????pCodec?=?avcodec_find_decoder(AV_CODEC_ID_H264);??

????????pCodecCtx?=?avcodec_alloc_context3(pCodec);??

????????pCodecCtx->pix_fmt?=?PIX_FMT_YUV420P;??

????????pCodecCtx->width?=?codec_.width;??

????????pCodecCtx->height?=?codec_.height;??

????????//pCodecCtx->bit_rate?=?codec_.targetBitrate*1000;??

????????pCodecCtx->time_base.num?=?1;??

????????pCodecCtx->time_base.den?=?codec_.maxFramerate;??

??

????????if?(pCodec?==?NULL){??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264DecoderImpl::InitDecode,?Codec?not?found.");??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

????????if?(avcodec_open2(pCodecCtx,?pCodec,?NULL)?<?0){??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264DecoderImpl::InitDecode,?Could?not?open?codec.");??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

????????inited_?=?true;??

??

????????//?Always?start?with?a?complete?key?frame.??

????????key_frame_required_?=?true;??

????????WEBRTC_TRACE(webrtc::kTraceApiCall,?webrtc::kTraceVideoCoding,?-1,??

????????????"H264DecoderImpl::InitDecode(width:%d,?height:%d,?framerate:%d,?start_bitrate:%d,?max_bitrate:%d)",??

????????????inst->width,?inst->height,?inst->maxFramerate,?inst->startBitrate,?inst->maxBitrate);??

????????return?WEBRTC_VIDEO_CODEC_OK;??

????}??

Decode方法的實現改寫如下 [cpp]?view plaincopy

int?H264DecoderImpl::Decode(const?EncodedImage&?input_image,??

????????bool?missing_frames,??

????????const?RTPFragmentationHeader*?fragmentation,??

????????const?CodecSpecificInfo*?codec_specific_info,??

????????int64_t?/*render_time_ms*/)?{??

????????if?(!inited_)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264DecoderImpl::Decode,?decoder?is?not?initialized");??

????????????return?WEBRTC_VIDEO_CODEC_UNINITIALIZED;??

????????}??

??

????????if?(decode_complete_callback_?==?NULL)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264DecoderImpl::Decode,?decode?complete?call?back?is?not?set");??

????????????return?WEBRTC_VIDEO_CODEC_UNINITIALIZED;??

????????}??

??

????????if?(input_image._buffer?==?NULL)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264DecoderImpl::Decode,?null?buffer");??

????????????return?WEBRTC_VIDEO_CODEC_ERR_PARAMETER;??

????????}??

????????if?(!codec_specific_info)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::Decode,?no?codec?info");??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

????????if?(codec_specific_info->codecType?!=?kVideoCodecH264)?{??

????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????"H264EncoderImpl::Decode,?non?h264?codec?%d",?codec_specific_info->codecType);??

????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????}??

??

????????WEBRTC_TRACE(webrtc::kTraceApiCall,?webrtc::kTraceVideoCoding,?-1,??

????????????"H264DecoderImpl::Decode(frame_type:%d,?length:%d",??

????????????input_image._frameType,?input_image._length);??

??????

????????if?(framecnt?<?2)??

????????{//存儲最開始的SPS?PPS?和?IDR幀以便進行初始的解碼??

????????????memcpy(decode_buffer?+?encoded_length,?input_image._buffer,?input_image._length);??

????????????encoded_length?+=?input_image._length;??

????????????framecnt++;??

????????}??

????????else??

????????{??

????????????pFrame?=?av_frame_alloc();??

????????????pFrameYUV?=?av_frame_alloc();??

????????????out_buffer?=?(uint8_t?*)av_malloc(avpicture_get_size(PIX_FMT_YUV420P,?pCodecCtx->width,?pCodecCtx->height));??

????????????avpicture_fill((AVPicture?*)pFrameYUV,?out_buffer,?PIX_FMT_YUV420P,?pCodecCtx->width,?pCodecCtx->height);??

????????????img_convert_ctx?=?sws_getContext(pCodecCtx->width,?pCodecCtx->height,?pCodecCtx->pix_fmt,??

????????????????pCodecCtx->width,?pCodecCtx->height,?PIX_FMT_YUV420P,?SWS_BICUBIC,?NULL,?NULL,?NULL);??

??????????????

????????????if?(framecnt?==?2)??

????????????{??

????????????????packet?=?(AVPacket?*)av_malloc(sizeof(AVPacket));??

????????????????av_new_packet(packet,?encoded_length);??

????????????????memcpy(packet->data,?decode_buffer,?encoded_length);??

????????????????av_free(decode_buffer);??

????????????????framecnt++;??

????????????????printf("\n\nLoading");??

????????????}??

????????????else??

????????????{??

????????????????packet?=?(AVPacket?*)av_malloc(sizeof(AVPacket));??

????????????????av_new_packet(packet,?input_image._length);??

????????????????memcpy(packet->data,?input_image._buffer,?input_image._length);??

????????????}??

??????????????

????????????int?got_picture?=?0;??

????????????int?ret?=?avcodec_decode_video2(pCodecCtx,?pFrame,?&got_picture,?packet);??

????????????if?(ret?<?0){??

????????????????WEBRTC_TRACE(webrtc::kTraceError,?webrtc::kTraceVideoCoding,?-1,??

????????????????????"H264DecoderImpl::Decode,?Decode?Error.");??

????????????????return?WEBRTC_VIDEO_CODEC_ERROR;??

????????????}??

????????????if?(got_picture){??

????????????????sws_scale(img_convert_ctx,?(const?uint8_t*?const*)pFrame->data,?pFrame->linesize,?0,?pCodecCtx->height,??

????????????????????pFrameYUV->data,?pFrameYUV->linesize);??

??

????????????????int?size_y?=?pFrameYUV->linesize[0]?*?pCodecCtx->height;??

????????????????int?size_u?=?pFrameYUV->linesize[1]?*?pCodecCtx->height?/?2;??

????????????????int?size_v?=?pFrameYUV->linesize[2]?*?pCodecCtx->height?/?2;??

??

????????????????decoded_image_.CreateFrame(size_y,?static_cast<uint8_t*>(pFrameYUV->data[0]),??

????????????????????size_u,?static_cast<uint8_t*>(pFrameYUV->data[1]),??

????????????????????size_v,?static_cast<uint8_t*>(pFrameYUV->data[2]),??

????????????????????pCodecCtx->width,??

????????????????????pCodecCtx->height,??

????????????????????pFrameYUV->linesize[0],??

????????????????????pFrameYUV->linesize[1],??

????????????????????pFrameYUV->linesize[2]);??

??

????????????????decoded_image_.set_timestamp(input_image._timeStamp);??

????????????????decode_complete_callback_->Decoded(decoded_image_);??

????????????????return?WEBRTC_VIDEO_CODEC_OK;??

????????????}??

????????????else??

????????????????printf(".");??

????????????av_free_packet(packet);??

????????}??

????????return?WEBRTC_VIDEO_CODEC_OK;??

????}??

其他方法的實現保持不變，至此ffmpeg解碼功能的重新封裝也完成了。 從最后實現的效果來看，X264的視頻質量的確是最好的，但是播放端的解碼延時比較高，暫時還不清楚原因，希望了解的朋友指教。
本項目源代碼

轉載于:https://www.cnblogs.com/x_wukong/p/4880961.html

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