ffmepg+SDL2实现的视频播放器

/*=========================================================================\ * Copyright(C)2016 Chudai. * * File name : video.c * Version : v1.0.0 * Author : 初代 * Date : 2016/10/07 * Description : * Function list: 1. * 2. * 3. * History : \*=========================================================================*/ /*-----------------------------------------------------------* * 头文件 * *-----------------------------------------------------------*/ #include "video.h" /*======================================================================\ * Author (作者): i.sshe * Date (日期): 2016/10/07 * Others (其他): 一些准备工作 \*=======================================================================*/ int prepare_video(PlayerState *ps) { ps->pvideo_stream = ps->pformat_ctx->streams[ps->video_stream_index]; ps->pvideo_codec_ctx = ps->pvideo_stream->codec; ps->pvideo_codec = avcodec_find_decoder(ps->pvideo_codec_ctx->codec_id); if (ps->pvideo_codec == NULL) { fprintf(ERR_STREAM, "Couldn't find video decoder\n"); return (-1); } //打开解码器 if (avcodec_open2(ps->pvideo_codec_ctx, ps->pvideo_codec, NULL) < 0) { fprintf(ERR_STREAM, "Couldn't open video decoder\n"); return -1; } return 0; } /*======================================================================\ * Author (作者): i.sshe * Date (日期): 2016/10/07 * Others (其他): 其实这里还算准备工作，开窗口什么的 \*=======================================================================*/ int play_video(PlayerState *ps) { printf("play video!!!\n"); ps->pixel_w = ps->pvideo_codec_ctx->width; ps->pixel_h = ps->pvideo_codec_ctx->height; ps->window_w = ps->pixel_w; ps->window_h = ps->pixel_h; ps->pixfmt = AV_PIX_FMT_YUV420P; ps->out_frame.format = AV_PIX_FMT_YUV420P; ps->out_frame.width = ps->pixel_w; ps->out_frame.height = ps->pixel_h; // ps->video_buf = (uint8_t *)av_malloc( avpicture_get_size(ps->pixfmt, ps->out_frame.width, ps->out_frame.height) ); //用av_image_fill_arrays代替。 //根据所给参数和提供的数据设置data指针和linesizes。 avpicture_fill((AVPicture *)&ps->out_frame, ps->video_buf, ps->pixfmt, ps->out_frame.width, ps->out_frame.height); //使用sws_scale之前要用这个函数进行相关转换操作。 //分配和返回一个 SwsContext. //sws_freeContext(ps->psws_ctx); 需要用这个函数free内存。 //现在因为只用了一次sws_getContext()所以，这个内存在main释放。 //因为一直输出格式什么都一样，所以没有放在靠近sws_scale的地方。 ps->psws_ctx = sws_getContext(ps->pixel_w, ps->pixel_h, ps->pvideo_codec_ctx->pix_fmt, ps->out_frame.width, ps->out_frame.height, ps->pixfmt, SWS_BILINEAR, NULL, NULL, NULL); ps->sdl_rect.x = 0; ps->sdl_rect.y = 0; //创建窗口 //SDL_WINDOW_RESIZABLE: 使窗口可以拉伸 ps->pwindow = SDL_CreateWindow("Isshe Video Player!", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, ps->window_w, ps->window_h, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE); if (ps->pwindow == NULL) { fprintf(ERR_STREAM, "Couldn't Create Window\n"); exit(-1); // } //新建一个渲染器 ps->prenderer = SDL_CreateRenderer(ps->pwindow, -1, 0); ps->ptexture = SDL_CreateTexture(ps->prenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, ps->pixel_w, ps->pixel_h); //新建线程运行刷新函数 SDL_CreateThread(refresh_fun, "refresh func", ps); return 0; } /*======================================================================\ * Author (作者): i.sshe * Date (日期): 2016/10/08 * Others (其他): 刷新函数 \*=======================================================================*/ int refresh_fun(void *arg) { SDL_Event event; PlayerState *ps = (PlayerState*) arg; while(ps->quit == 0) { event.type = ISSHE_REFRESH_EVENT; SDL_PushEvent(&event); SDL_Delay(ps->delay); } return 0; } /*======================================================================\ * Author (作者): i.sshe * Date (日期): 2016/10/07 * Others (其他): \*=======================================================================*/ int decode_and_show(void *arg) { printf("decode_video!!!\n"); PlayerState *ps = (PlayerState *)arg; AVPacket packet ; AVFrame *pframe = av_frame_alloc(); AVFrame *tempframe = av_frame_alloc(); double pts = 0.0; int ret = 0; // ... if (ps->quit == 1) return 0; if (ps->video_packet_queue.nb_packets == 0) { return 0; } //从packet队列取一个packet出来解码 ret = packet_queue_get(&ps->video_packet_queue, &packet, 1); if (ret < 0) { fprintf(ERR_STREAM, "Get video packet error\n"); return -1; // } ret = avcodec_send_packet(ps->pvideo_codec_ctx, &packet); if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF) { fprintf(ERR_STREAM, "send video packet error\n"); return -1; // } ret = avcodec_receive_frame(ps->pvideo_codec_ctx, pframe); if (ret < 0 && ret != AVERROR_EOF) { fprintf(ERR_STREAM, "receive video frame error\n"); return -1; } //下面三句实现音视频同步，还有一句在audio部分。 //获取pts pts = get_frame_pts(ps, pframe); //ps中用cur_frame_pts是为了减少get_delay()的参数 ps->cur_frame_pts = pts; //*(double *)pframe.opaque; ps->delay = get_delay(ps) * 1000 + 0.5; printf("video frame pts = %lf\n", pts); printf("显示里面：ps->delay = %d\n", ps->delay); //这个函数看了手册也不大理解 sws_scale(ps->psws_ctx, (uint8_t const *const *)pframe->data, pframe->linesize, 0, ps->pixel_h, ps->out_frame.data, ps->out_frame.linesize); ps->sdl_rect.w = ps->window_w; ps->sdl_rect.h = ps->window_h; SDL_UpdateTexture(ps->ptexture, NULL, ps->out_frame.data[0], ps->out_frame.linesize[0]); SDL_RenderClear(ps->prenderer); SDL_RenderCopy(ps->prenderer, ps->ptexture, NULL, &ps->sdl_rect); SDL_RenderPresent(ps->prenderer); av_frame_free(&pframe); return 0; } /*======================================================================\ * Author (作者): i.sshe * Date (日期): 2016/10/08 * Others (其他): 获取延迟时间 \*=======================================================================*/ double get_delay(PlayerState *ps) { double ret_delay = 0.0; double frame_delay = 0.0; double cur_audio_clock = 0.0; double compare = 0.0; double threshold = 0.0; //这里的delay是秒为单位， 化为毫秒：*1000 frame_delay = ps->cur_frame_pts - ps->pre_frame_pts; if (frame_delay <= 0 || frame_delay >= 1.0) { frame_delay = ps->pre_cur_frame_delay; } //两帧之间的延时 ps->pre_cur_frame_delay = frame_delay; ps->pre_frame_pts = ps->cur_frame_pts; cur_audio_clock = get_audio_clock(ps); //compare < 0 说明慢了， > 0说明快了 compare = ps->cur_frame_pts - cur_audio_clock; //设置一个阀值, 是一个正数 //这里设阀值为两帧之间的延迟， threshold = frame_delay; //SYNC_THRESHOLD ? frame_delay : SYNC_THRESHOLD; if (compare <= -threshold) //慢， 加快速度 { ret_delay = frame_delay / 2; } else if (compare >= threshold) //快了，就在上一帧延时的基础上加长延时 { ret