EasyPlayerPro for Windows是基于ffmpeg進行開發的全功能播放器，開發過程中參考了很多開源的播放器，諸如vlc和ffplay等，其中最強大的莫過于vlc，但是鑒于vlc框架過于龐大而其中仍存在諸多問題而舍棄了，而其他的更傾向于演示demo，只能提供部分借鑒意義；故而，EasyPlayerPro 一貫秉承Easy系列小而精，接口簡單功能強大的宗旨從新設計了一套框架，該套框架能適應多線程調用以及多個播放實例同時運行，和EasyPlayer一樣Easy; 當然，在此也鄭重的感謝各大開源播放器以及ffmpeg的作者的無私奉獻。
EasyPlayerPro分為三大模塊：打開模塊，讀取流數據模塊，解碼模塊和渲染模塊，其中：
(1) 打開模塊 打開流模塊很簡單，教科書式的調用方法：
player->avformat_context = avformat_alloc_context();player->avformat_context->interrupt_callback.callback = interrupt_cb;player->avformat_context->interrupt_callback.opaque = player;// open input fileAVDictionary *options = NULL;//av_dict_set(&options, "rtsp_transport", "udp", 0);if (avformat_open_input(&player->avformat_context, url, fmt, &options) != 0) {goto error_handler;}// find stream infoif (avformat_find_stream_info(player->avformat_context, NULL) < 0) {goto error_handler;}// set current audio & video streamfor (i=0,idx=-1,cur=-1; i<(int)player->avformat_context->nb_streams; i++) {
switch (type) {caseAVMEDIA_TYPE_AUDIO:// getlastcodeccontextif (player->acodec_context) {lastctxt = player->acodec_context;}// get new acodec_context & astream_timebaseplayer->acodec_context = player->avformat_context->streams[idx]->codec;player->astream_timebase = player->avformat_context->streams[idx]->time_base;// reopen codecif (lastctxt) avcodec_close(lastctxt);decoder = avcodec_find_decoder(player->acodec_context->codec_id);if (decoder && avcodec_open2(player->acodec_context, decoder, NULL) == 0) {player->astream_index = idx;}else {av_log(NULL, AV_LOG_WARNING, "failed to find or open decoder for audio !\n");player->astream_index = -1;}break;caseAVMEDIA_TYPE_VIDEO:// get last codec contextif (player->vcodec_context) {lastctxt = player->vcodec_context;}// get new vcodec_context & vstream_timebaseplayer->vcodec_context = player->avformat_context->streams[idx]->codec;player->vstream_timebase = player->avformat_context->streams[idx]->time_base;// reopen codecif (lastctxt) avcodec_close(lastctxt);decoder = avcodec_find_decoder(player->vcodec_context->codec_id);if (decoder && avcodec_open2(player->vcodec_context, decoder, NULL) == 0) {player->vstream_index = idx;}else {av_log(NULL, AV_LOG_WARNING, "failed to find or open decoder for video !\n");player->vstream_index = -1;}break;caseAVMEDIA_TYPE_SUBTITLE:return -1; // todo...}}if (idx == -1) return -1;// for audioif (player->astream_index != -1){arate = player->acodec_context->sample_rate;aformat = player->acodec_context->sample_fmt;alayout = player->acodec_context->channel_layout;//++ fix audio channel layout issueif (alayout == 0) {alayout = av_get_default_channel_layout(player->acodec_context->channels);}//-- fix audio channel layout issue}// for videoif (player->vstream_index != -1) {vrate = player->avformat_context->streams[player->vstream_index]->r_frame_rate;if (vrate.num / vrate.den >= 100) {vrate.num = 25;vrate.den = 1;}player->vcodec_context->pix_fmt = vformat;width = player->vcodec_context->width;height = player->vcodec_context->height;}
(3) 解碼模塊 解碼模塊分為音頻和視頻解碼模塊，音視頻的解碼流程非常相似， 主要分為三步： a. 從隊列中讀取音視頻編碼數據； b. 音視頻分別采用avcodec_decode_audio4和avcodec_decode_video2進行解碼； c. 音視頻渲染； 這里著重講解視頻的解碼后的過程，其中涉及到解碼后的原始圖像數據進行處理，解碼出一幀圖像以后，我們需要對其進行字幕和圖像或者其他的視頻圖像的疊加，借助ffmpeg強大的圖像轉換和縮放能力，借助VFX庫我們很容易實現：
(4) 渲染模塊 渲染模塊分為音頻渲染和視頻渲染，音頻渲染即播放，使用waveOutOpen，waveOutWrite等waveout函數即可實現，下面重點說一下視頻渲染，視頻渲染通俗講也就是圖像繪制，Windows平臺可采用D3D,DDraw, GDI，OpenGL等多種方式進行呈現，本文主要采用3種渲染方式，D3D，GDI和OpenGL； 為了保證渲染的流暢性，我們創建線程執行渲染， a. 讀取解碼圖像隊列； b. 音視頻時間戳同步處理； c. D3D/gdi/openGL渲染：
