打开读取文件->解复用->
1.如果是视频流->解码成yuv->纹理->渲染器->播放
2.如果是音频流->不解码放入缓存队列->sdl音频回调函数(同时解码)->播放
其中打开文件,解复用,解码使用ffmpeg,纹理,渲染,播放是sdl完成的。
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#include <stdio.h> #include <assert.h> #include <SDL.h> #include <libavcodec/avcodec.h> #include <libavformat/avformat.h> #include <libswscale/swscale.h> #include <libswresample/swresample.h> // compatibility with newer API #if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(55,28,1) #define av_frame_alloc avcodec_alloc_frame #define av_frame_free avcodec_free_frame #endif #define SDL_AUDIO_BUFFER_SIZE 1024 #define MAX_AUDIO_FRAME_SIZE 192000 struct SwrContext *audio_convert_ctx = NULL; typedef struct PacketQueue { AVPacketList *first_pkt, *last_pkt; int nb_packets; int size; SDL_mutex *mutex; SDL_cond *cond; } PacketQueue; PacketQueue audioq; int quit = 0; void packet_queue_init(PacketQueue *q) { memset(q, 0, sizeof(PacketQueue)); q->mutex = SDL_CreateMutex(); q->cond = SDL_CreateCond(); } int packet_queue_put(PacketQueue *q, AVPacket *pkt) { AVPacketList *pkt1; if(av_dup_packet(pkt) < 0) { return -1; } pkt1 = av_malloc(sizeof(AVPacketList)); if (!pkt1) return -1; pkt1->pkt = *pkt; pkt1->next = NULL; SDL_LockMutex(q->mutex); if (!q->last_pkt) { q->first_pkt = pkt1; }else{ q->last_pkt->next = pkt1; } q->last_pkt = pkt1; q->nb_packets++; q->size += pkt1->pkt.size; SDL_CondSignal(q->cond); SDL_UnlockMutex(q->mutex); return 0; } int packet_queue_get(PacketQueue *q, AVPacket *pkt, int block) { AVPacketList *pkt1; int ret; SDL_LockMutex(q->mutex); for(;;) { if(quit) { ret = -1; break; } pkt1 = q->first_pkt; if (pkt1) { q->first_pkt = pkt1->next; if (!q->first_pkt) q->last_pkt = NULL; q->nb_packets--; q->size -= pkt1->pkt.size; *pkt = pkt1->pkt; av_free(pkt1); ret = 1; break; } else if (!block) { ret = 0; break; } else { SDL_CondWait(q->cond, q->mutex); } } SDL_UnlockMutex(q->mutex); return ret; } int audio_decode_frame(AVCodecContext *aCodecCtx, uint8_t *audio_buf, int buf_size) { static AVPacket pkt; static uint8_t *audio_pkt_data = NULL; static int audio_pkt_size = 0; static AVFrame frame; int len1, data_size = 0; for(;;) { while(audio_pkt_size > 0) { int got_frame = 0; len1 = avcodec_decode_audio4(aCodecCtx, &frame, &got_frame, &pkt); if(len1 < 0) { /* if error, skip frame */ audio_pkt_size = 0; break; } audio_pkt_data += len1; audio_pkt_size -= len1; data_size = 0; if(got_frame) { //fprintf(stderr, "channels:%d, nb_samples:%d, sample_fmt:%d \n", aCodecCtx->channels, frame.nb_samples, aCodecCtx->sample_fmt); /* data_size = av_samples_get_buffer_size(NULL, aCodecCtx->channels, frame.nb_samples, aCodecCtx->sample_fmt, 1); */ data_size = 2 * 2 * frame.nb_samples; assert(data_size <= buf_size); swr_convert(audio_convert_ctx, &audio_buf, MAX_AUDIO_FRAME_SIZE*3/2, (const uint8_t **)frame.data, frame.nb_samples); //memcpy(audio_buf, frame.data[0], data_size); } if(data_size <= 0) { /* No data yet, get more frames */ continue; } /* We have data, return it and come back for more later */ return data_size; } if(pkt.data) av_free_packet(&pkt); if(quit) { return -1; } if(packet_queue_get(&audioq, &pkt, 1) < 0) { return -1; } audio_pkt_data = pkt.data; audio_pkt_size = pkt.size; } } void audio_callback(void *userdata, Uint8 *stream, int len) { AVCodecContext *aCodecCtx = (AVCodecContext *)userdata; int len1, audio_size; static uint8_t audio_buf[(MAX_AUDIO_FRAME_SIZE * 3) / 2]; static unsigned int audio_buf_size = 0; static unsigned int audio_buf_index = 0; while(len > 0) { if(audio_buf_index >= audio_buf_size) { /* We have already sent all our data; get more */ audio_size = audio_decode_frame(aCodecCtx, audio_buf, sizeof(audio_buf)); if(audio_size < 0) { /* If error, output silence */ audio_buf_size = 1024; // arbitrary? memset(audio_buf, 0, audio_buf_size); } else { audio_buf_size = audio_size; } audio_buf_index = 0; } len1 = audio_buf_size - audio_buf_index; if(len1 > len) len1 = len; fprintf(stderr, "index=%d, len1=%d, len=%d\n", audio_buf_index, len, len1); memcpy(stream, (uint8_t *)audio_buf + audio_buf_index, len1); len -= len1; stream += len1; audio_buf_index += len1; } } int main(int argc, char *argv[]) { int ret = -1; int i, videoStream, audioStream; AVFormatContext *pFormatCtx = NULL; //for video decode AVCodecContext *pCodecCtxOrig = NULL; AVCodecContext *pCodecCtx = NULL; AVCodec *pCodec = NULL; struct SwsContext *sws_ctx = NULL; AVPicture *pict = NULL; AVFrame *pFrame = NULL; AVPacket packet; int frameFinished; //for audio decode AVCodecContext *aCodecCtxOrig = NULL; AVCodecContext *aCodecCtx = NULL; AVCodec *aCodec = NULL; int64_t in_channel_layout; int64_t out_channel_layout; //for video render int w_width = 640; int w_height = 480; int pixformat; SDL_Rect rect; SDL_Window *win; SDL_Renderer *renderer; SDL_Texture *texture; //for event SDL_Event event; //for audio SDL_AudioSpec wanted_spec, spec; if(argc < 2) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Usage: command <file>"); return ret; } // Register all formats and codecs av_register_all(); if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Could not initialize SDL - %s\n", SDL_GetError()); return ret; } // Open video file if(avformat_open_input(&pFormatCtx, argv[1], NULL, NULL)!=0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to open multi-media file"); goto __FAIL; // Couldn't open file } // Retrieve stream information if(avformat_find_stream_info(pFormatCtx, NULL)<0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't find stream information "); goto __FAIL; } // Dump information about file onto standard error av_dump_format(pFormatCtx, 0, argv[1], 0); // Find the first video stream videoStream=-1; audioStream=-1; for(i=0; i<pFormatCtx->nb_streams; i++) { if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO && videoStream < 0) { videoStream=i; } if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_AUDIO && audioStream < 0) { audioStream=i; } } if(videoStream==-1) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, " Didn't find a video stream "); goto __FAIL; // Didn't find a video stream } if(audioStream==-1) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, " Didn't find a audio stream "); goto __FAIL; // Didn't find a video stream } aCodecCtxOrig=pFormatCtx->streams[audioStream]->codec; aCodec = avcodec_find_decoder(aCodecCtxOrig->codec_id); if(!aCodec) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unsupported codec! "); goto __FAIL; // Didn't find a video stream } // Copy context aCodecCtx = avcodec_alloc_context3(aCodec); if(avcodec_copy_context(aCodecCtx, aCodecCtxOrig) != 0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't copy codec context! "); goto __FAIL; // Didn't find a video stream } // Set audio settings from codec info wanted_spec.freq = aCodecCtx->sample_rate; wanted_spec.format = AUDIO_S16SYS; wanted_spec.channels = aCodecCtx->channels; wanted_spec.silence = 0; wanted_spec.samples = SDL_AUDIO_BUFFER_SIZE; wanted_spec.callback = audio_callback; wanted_spec.userdata = aCodecCtx; if(SDL_OpenAudio(&wanted_spec, &spec) < 0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to open audio device - %s!", SDL_GetError()); goto __FAIL; } avcodec_open2(aCodecCtx, aCodec, NULL); packet_queue_init(&audioq); in_channel_layout = av_get_default_channel_layout(aCodecCtx->channels); out_channel_layout = in_channel_layout; //AV_CH_LAYOUT_STEREO; fprintf(stderr, "in layout:%lld, out layout:%lld \n", in_channel_layout, out_channel_layout); audio_convert_ctx = swr_alloc(); if(audio_convert_ctx){ swr_alloc_set_opts(audio_convert_ctx, out_channel_layout, AV_SAMPLE_FMT_S16, aCodecCtx->sample_rate, in_channel_layout, aCodecCtx->sample_fmt, aCodecCtx->sample_rate, 0, NULL); } swr_init(audio_convert_ctx); SDL_PauseAudio(0); // Get a pointer to the codec context for the video stream pCodecCtxOrig=pFormatCtx->streams[videoStream]->codec; // Find the decoder for the video stream pCodec=avcodec_find_decoder(pCodecCtxOrig->codec_id); if(pCodec==NULL) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unsupported codec!"); goto __FAIL; } // Copy context pCodecCtx = avcodec_alloc_context3(pCodec); if(avcodec_copy_context(pCodecCtx, pCodecCtxOrig) != 0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to copy context of codec!"); goto __FAIL; } // Open codec if(avcodec_open2(pCodecCtx, pCodec, NULL)<0) { SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to open audio decoder!"); goto __FAIL; } // Allocate video frame pFrame=av_frame_alloc(); w_width = pCodecCtx->width; w_height = pCodecCtx->height; fprintf(stderr, "width:%d, height:%d\n", w_width, w_height); win = SDL_CreateWindow("Media Player", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, w_width, w_height, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE); if(!win){ SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to create window!"); goto __FAIL; } renderer = SDL_CreateRenderer(win, -1, 0); if(!renderer){ SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to create renderer!"); goto __FAIL; } pixformat = SDL_PIXELFORMAT_IYUV; texture = SDL_CreateTexture(renderer, pixformat, SDL_TEXTUREACCESS_STREAMING, w_width, w_height); if(!texture){ SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to create Texture!"); goto __FAIL; } // initialize SWS context for software scaling sws_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_YUV420P, SWS_BILINEAR, NULL, NULL, NULL); pict = (AVPicture*)malloc(sizeof(AVPicture)); avpicture_alloc(pict, AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height); // Read frames and save first five frames to disk while(av_read_frame(pFormatCtx, &packet)>=0) { // Is this a packet from the video stream? if(packet.stream_index==videoStream) { // Decode video frame avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet); // Did we get a video frame? if(frameFinished) { // Convert the image into YUV format that SDL uses sws_scale(sws_ctx, (uint8_t const * const *)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pict->data, pict->linesize); SDL_UpdateYUVTexture(texture, NULL, pict->data[0], pict->linesize[0], pict->data[1], pict->linesize[1], pict->data[2], pict->linesize[2]); rect.x = 0; rect.y = 0; rect.w = pCodecCtx->width; rect.h = pCodecCtx->height; SDL_RenderClear(renderer); SDL_RenderCopy(renderer, texture, NULL, &rect); SDL_RenderPresent(renderer); av_free_packet(&packet); } } else if(packet.stream_index==audioStream) { //for audio packet_queue_put(&audioq, &packet); } else { av_free_packet(&packet); } // Free the packet that was allocated by av_read_frame SDL_PollEvent(&event); switch(event.type) { case SDL_QUIT: quit = 1; goto __QUIT; break; default: break; } } __QUIT: ret = 0; __FAIL: // Free the YUV frame if(pFrame){ av_frame_free(&pFrame); } // Close the codecs if(pCodecCtxOrig){ avcodec_close(pCodecCtxOrig); } if(pCodecCtx){ avcodec_close(pCodecCtx); } if(aCodecCtxOrig) { avcodec_close(aCodecCtxOrig); } if(aCodecCtx) { avcodec_close(aCodecCtx); } // Close the video file if(pFormatCtx){ avformat_close_input(&pFormatCtx); } if(pict){ avpicture_free(pict); free(pict); } if(win){ SDL_DestroyWindow(win); } if(renderer){ SDL_DestroyRenderer(renderer); } if(texture){ SDL_DestroyTexture(texture); } SDL_Quit(); return ret; }