ffmpeg 0.6.3 能用的tutorial04

编译命令：
gcc -o tutorial04 tutorial04.c -lavformat -lavcodec -lz -lm -lswscale `sdl-config --cflags --libs`

点击(此处)折叠或打开

 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 #include <libswscale/swscale.h>
 #include <SDL.h>
 #include <SDL_thread.h>

 #include <stdio.h>
 #include <math.h>

 #define SDL_AUDIO_BUFFER_SIZE 1024
 #define MAX_AUDIOQ_SIZE (5*16*1024)
 #define MAX_VIDEOQ_SIZE (5*256*1024)
 #define FF_ALLOC_EVENT (SDL_USEREVENT)
 #define FF_REFRESH_EVENT (SDL_USEREVENT + 1)
 #define FF_QUIT_EVENT (SDL_USEREVENT + 2)
 #define VIDEO_PICTURE_QUEUE_SIZE 1

 static struct SwsContext *img_convert_ctx;

 typedef struct PacketQueue {
     AVPacketList *first_pkt, *last_pkt;
     int nb_packets;
     int size;
     SDL_mutex *mutex;
     SDL_cond *cond;
 } PacketQueue;

 typedef struct VideoPicture {
     SDL_Overlay *bmp;
     int width, height;
     int allocated;
 } VideoPicture;

 typedef struct VideoState {
     AVFormatContext *pFormatCtx;
     int videoStream, audioStream;
     AVStream *audio_st;
     PacketQueue audioq;
     uint8_t audio_buf[(AVCODEC_MAX_AUDIO_FRAME_SIZE * 3)/2];
     unsigned int audio_buf_size;
     unsigned int audio_buf_index;
     AVPacket audio_pkt;
     uint8_t *audio_pkt_data;
     int *audio_pkt_size;
     AVStream *video_st;
     PacketQueue videoq;

     VideoPicture pictq[VIDEO_PICTURE_QUEUE_SIZE];
     int pictq_size, pictq_rindex, pictq_windex;
     SDL_mutex *pictq_mutex;
     SDL_cond *pictq_cond;

     SDL_Thread *parse_tid;
     SDL_Thread *video_tid;

     char filename[1024];
     int quit;
 } VideoState;

 SDL_Surface *screen;

 VideoState *global_video_state;

 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;
 }

 static int packet_queue_get(PacketQueue *q, AVPacket *pkt, int block) {
     AVPacketList *pkt1;
     int ret;

     SDL_LockMutex(q->mutex);

     for (;;) {
         if (global_video_state->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_decodec_frame(VideoState *is, uint8_t *audio_buf, int buf_size) {
     int len1, data_size;
     AVPacket *pkt = &is->audio_pkt;

     for (;;) {
         while(is->audio_pkt_size > 0) {
             data_size = buf_size;
             len1 = avcodec_decode_audio2(is->audio_st->codec,
                                 (int16_t*)audio_buf, &data_size,
                             is->audio_pkt_data, is->audio_pkt_size);
             if (len1 < 0) {
                 is->audio_pkt_size = 0;
                 break;
             }
             is->audio_pkt_data += len1;
             is->audio_pkt_size -= len1;
             if (data_size <= 0) {
                 continue;
             }
             return data_size;
         }
         if (pkt->data) {
             av_free_packet(pkt);
         }
         if (is->quit) {
             return -1;
         }

         if (packet_queue_get(&is->audioq, pkt, 1) < 0) {
             return -1;
         }
         is->audio_pkt_data = pkt->data;
         is->audio_pkt_size = pkt->size;
     }
 }

 void audio_callback(void *userdata, Uint8 *stream, int len) {
     VideoState *is = (VideoState *)userdata;
     int len1, audio_size;

     while(len > 0) {
         if (is->audio_buf_index >= is->audio_buf_size) {
             audio_size = audio_decodec_frame(is, is->audio_buf, sizeof(is->audio_buf));
             if (audio_size < 0) {
                 is->audio_buf_size = 1024;
                 memset(is->audio_buf, 0, is->audio_buf_size);
             } else {
                 is->audio_buf_size = audio_size;
             }
             is->audio_buf_index = 0;
         }
         len1 = is->audio_buf_size - is->audio_buf_index;
         if (len1 > len) {
             len1 = len;
         }
         memcpy(stream, (uint8_t*)is->audio_buf + is->audio_buf_index, len1);
         len -= len1;
         stream += len1;
         is->audio_buf_index += len1;
     }
 }

 static Uint32 sdl_refresh_timer_cb(Uint32 interval, void *opaque) {
     SDL_Event event;
     event.type = FF_REFRESH_EVENT;
     event.user.data1 = opaque;
     SDL_PushEvent(&event);
     return 0;
 }

 static void schedule_refresh(VideoState *is, int delay) {
     SDL_AddTimer(delay, sdl_refresh_timer_cb, is);
 }

 void video_display(VideoState *is) {
     SDL_Rect rect;
     VideoPicture *vp;
     AVPicture pict;
     float aspect_ratio;
     int w, h, x, y;
     int i;

     vp = &is->pictq[is->pictq_rindex];
     if (vp->bmp) {
         if (is->video_st->codec->sample_aspect_ratio.num == 0) {
             aspect_ratio = 0;
         } else {
             aspect_ratio = av_q2d(is->video_st->codec->sample_aspect_ratio)*is->video_st->codec->width / is->video_st->codec->height;
         }
         if (aspect_ratio <= 0.0) {
             aspect_ratio = (float)is->video_st->codec->width / (float)is->video_st->codec->height;
         }
         h = screen->h;
         w = ((int)rint(h*aspect_ratio)) & -3;
         if (w > screen->w) {
             w = screen->w;
             h = ((int)rint(w / aspect_ratio)) & -3;
         }
         x = (screen->w - w) / 2;
         y = (screen->h - h) / 2;

         rect.x = x;
         rect.y = y;
         rect.w = w;
         rect.h = h;
         SDL_DisplayYUVOverlay(vp->bmp, &rect);
     }
 }

 void video_refresh_timer(void *userdata) {
     VideoState *is = (VideoState *)userdata;
     VideoPicture *vp;

     if (is->video_st) {
         if (is->pictq_size == 0) {
             schedule_refresh(is ,1);
         } else {
             vp = &is->pictq[is->pictq_rindex];
             schedule_refresh(is, 80);
             video_display(is);
             if (++is->pictq_rindex == VIDEO_PICTURE_QUEUE_SIZE) {
                 is->pictq_rindex = 0;
             }
             SDL_LockMutex(is->pictq_mutex);
             is->pictq_size--;
             SDL_CondSignal(is->pictq_cond);
             SDL_UnlockMutex(is->pictq_mutex);
         }
     } else {
         schedule_refresh(is, 100);
     }
 }

 void alloc_picture(void *userdata) {
     VideoState *is = (VideoState *)userdata;
     VideoPicture *vp;

     vp = &is->pictq[is->pictq_windex];
     if (vp->bmp) {
         SDL_FreeYUVOverlay(vp->bmp);
     }

     vp->bmp = SDL_CreateYUVOverlay(is->video_st->codec->width,
                            is->video_st->codec->height,
                        SDL_YV12_OVERLAY,
                        screen);
     vp->width = is->video_st->codec->width;
     vp->height = is->video_st->codec->height;

     SDL_LockMutex(is->pictq_mutex);
     vp->allocated = 1;
     SDL_CondSignal(is->pictq_cond);
     SDL_UnlockMutex(is->pictq_mutex);
 }

 int queue_picture(VideoState *is, AVFrame *pFrame) {
     VideoPicture *vp;
     int dst_pix_fmt;
     AVPicture pict;

     SDL_LockMutex(is->pictq_mutex);
     while (is->pictq_size >= VIDEO_PICTURE_QUEUE_SIZE && !is->quit) {
         SDL_CondWait(is->pictq_cond, is->pictq_mutex);
     }
     SDL_UnlockMutex(is->pictq_mutex);

     if (is->quit) {
         return -1;
     }

     vp = &is->pictq[is->pictq_windex];

     if (!vp->bmp || vp->width != is->video_st->codec->width || vp->height != is->video_st->codec->height) {
         SDL_Event event;

         vp->allocated = 0;
         event.type = FF_ALLOC_EVENT;
         event.user.data1 = is;
         SDL_PushEvent(&event);

         SDL_LockMutex(is->pictq_mutex);
         while (!vp->allocated && !is->quit) {
             SDL_CondWait(is->pictq_cond, is->pictq_mutex);
         }
         SDL_UnlockMutex(is->pictq_mutex);
         if (is->quit) {
             return -1;
         }
     }

     if (vp->bmp) {
         SDL_LockYUVOverlay(vp->bmp);
         dst_pix_fmt = PIX_FMT_YUV420P;

         pict.data[0] = vp->bmp->pixels[0];
         pict.data[1] = vp->bmp->pixels[2];
         pict.data[2] = vp->bmp->pixels[1];

         pict.linesize[0] = vp->bmp->pitches[0];
         pict.linesize[1] = vp->bmp->pitches[2];
         pict.linesize[2] = vp->bmp->pitches[1];

         //*
         sws_scale(img_convert_ctx,
                   pFrame->data,
               pFrame->linesize, 0,
               is->video_st->codec->height,
               pict.data,
               pict.linesize);
         //*/

         SDL_UnlockYUVOverlay(vp->bmp);
         if (++is->pictq_windex == VIDEO_PICTURE_QUEUE_SIZE) {
             is->pictq_windex = 0;
         }
         SDL_LockMutex(is->pictq_mutex);
         is->pictq_size++;
         SDL_UnlockMutex(is->pictq_mutex);
     }
     return 0;
 }

 int video_thread(void *arg) {
     VideoState *is = (VideoState *)arg;
     AVPacket pkt1, *packet = &pkt1;
     int len1, frameFinished;
     AVFrame *pFrame;

     pFrame = avcodec_alloc_frame();

     for (;;) {
         if (packet_queue_get(&is->videoq, packet, 1) < 0) {
             break;
         }
         len1 = avcodec_decode_video(is->video_st->codec, pFrame, &frameFinished, packet->data, packet->size);

         if (frameFinished) {
             if (queue_picture(is, pFrame) < 0) {
                 break;
             }
         }
         av_free_packet(packet);
     }
     av_free(pFrame);
     return 0;
 }

 int stream_component_open(VideoState *is, int stream_index) {
     AVFormatContext *pFormatCtx = is->pFormatCtx;
     AVCodecContext *codecCtx;
     AVCodec *codec;
     SDL_AudioSpec wanted_spec, spec;

     if (stream_index < 0 || stream_index >= pFormatCtx->nb_streams) {
         return -1;
     }

     codecCtx = pFormatCtx->streams[stream_index]->codec;
     ///*
     img_convert_ctx = sws_getContext(codecCtx->width,
             codecCtx->height,
             codecCtx->pix_fmt,
             codecCtx->width,
             codecCtx->height,
             PIX_FMT_YUV420P,
             SWS_BICUBIC,
             NULL, NULL, NULL);
             //*/

     if (codecCtx->codec_type == CODEC_TYPE_AUDIO) {
         wanted_spec.freq = codecCtx->sample_rate;
         wanted_spec.format = AUDIO_S16SYS;
         wanted_spec.channels = codecCtx->channels;
         wanted_spec.silence = 0;
         wanted_spec.samples = SDL_AUDIO_BUFFER_SIZE;
         wanted_spec.callback = audio_callback;
         wanted_spec.userdata = is;

         if (SDL_OpenAudio(&wanted_spec, &spec) < 0) {
             fprintf(stderr,"SDL_OpenAudio: %s\n", SDL_GetError());
             return -1;
         }
     }
     codec = avcodec_find_decoder(codecCtx->codec_id);
     if (!codec || (avcodec_open(codecCtx, codec)) < 0) {
         fprintf(stderr, "Unsupported codec!\n");
         return -1;
     }

     switch(codecCtx->codec_type) {
         case CODEC_TYPE_AUDIO:
             is->audioStream = stream_index;
             is->audio_st = pFormatCtx->streams[stream_index];
             is->audio_buf_size = 0;
             is->audio_buf_index = 0;
             memset(&is->audio_pkt, 0, sizeof(is->audio_pkt));
             packet_queue_init(&is->audioq);
             SDL_PauseAudio(0);
             break;
         case CODEC_TYPE_VIDEO:
             is->videoStream = stream_index;
             is->video_st = pFormatCtx->streams[stream_index];

             packet_queue_init(&is->videoq);
             is->video_tid = SDL_CreateThread(video_thread, is);
             break;
         default:
             break;
     }

 }

 int decode_interrupt_cb(void) {
     return (global_video_state && global_video_state->quit);
 }

 int decode_thread(void *arg) {
     VideoState *is = (VideoState*)arg;
     AVFormatContext *pFormatCtx;
     AVPacket pkt1, *packet = &pkt1;

     int video_index = -1;
     int audio_index = -1;
     int i;

     is->videoStream = -1;
     is->audioStream = -1;

     global_video_state = is;
     url_set_interrupt_cb(decode_interrupt_cb);
     if (av_open_input_file(&pFormatCtx, is->filename, NULL, 0, NULL) != 0) {
         return -1;
     }
     is->pFormatCtx = pFormatCtx;
     if (av_find_stream_info(pFormatCtx) < 0) {
         return -1;
     }

     dump_format(pFormatCtx, 0, is->filename, 0);

     for (i=0; i<pFormatCtx->nb_streams; i++) {
         if (pFormatCtx->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO && video_index < 0) {
             video_index = i;
         }
         if (pFormatCtx->streams[i]->codec->codec_type == CODEC_TYPE_AUDIO && audio_index < 0) {
             audio_index = i;
         }
     }

     if (audio_index >= 0) {
         stream_component_open(is, audio_index);
     }
     if (video_index >= 0) {
         stream_component_open(is, video_index);
     }

     if (is->videoStream < 0 || is->audioStream < 0) {
         fprintf(stderr, "%s: could not open codecs\n", is->filename);
         goto fail;
     }

     for (;;) {
         if (is->quit) {
             break;
         }
         if (is->audioq.size > MAX_AUDIOQ_SIZE || is->videoq.size > MAX_VIDEOQ_SIZE) {
             SDL_Delay(10);
             continue;
         }
         if (av_read_frame(is->pFormatCtx, packet) < 0) {
             if (url_ferror(&pFormatCtx->pb) == 0) {
                 SDL_Delay(100);
                 continue;
             } else {
                 break;
             }
         }
         if (packet->stream_index == is->videoStream) {
             packet_queue_put(&is->videoq, packet);
         } else if (packet->stream_index == is->audioStream){
             packet_queue_put(&is->audioq, packet);
         } else {
             av_free_packet(packet);
         }
     }
     while (!is->quit) {
         SDL_Delay(100);
     }

 fail:
     if (1) {
         SDL_Event event;
         event.type = FF_QUIT_EVENT;
         event.user.data1 = is;
         SDL_PushEvent(&event);
     }
     return 0;
 }

 int main(int argc, char *argv[]) {
     SDL_Event event;
     VideoState *is;

     is = av_mallocz(sizeof(VideoState));

     if (argc < 2) {
         fprintf(stderr, "Isage: test <file>\n");
         exit(1);
     }

     av_register_all();

     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
         fprintf(stderr, "Could not initialize SDL - %s\n", SDL_GetError());
         exit(1);
     }

     screen = SDL_SetVideoMode(640, 480, 24, 0);

     if (!screen) {
         fprintf(stderr, "SDL: could not set video mode - exiting\n");
         exit(1);
     }

     av_strlcpy(is->filename, argv[1], sizeof(is->filename));

     is->pictq_mutex = SDL_CreateMutex();
     is->pictq_cond = SDL_CreateCond();

     schedule_refresh(is, 40);

     is->parse_tid = SDL_CreateThread(decode_thread, is);
     if (!is->parse_tid) {
         av_free(is);
         return -1;
     }

     for (;;) {
         SDL_WaitEvent(&event);
         switch(event.type) {
             case FF_QUIT_EVENT:
             case SDL_QUIT:
                 is->quit = 1;
                 SDL_Quit();
                 return 0;
                 break;
             case FF_ALLOC_EVENT:
                 alloc_picture(event.user.data1);
                 break;
             case FF_REFRESH_EVENT:
                 video_refresh_timer(event.user.data1);
                 break;
             default:
                 break;
         }
     }
     return 0;
 }