An ffmpeg and SDL turorial:FFMpeg 和 SDL编程参考,修改了源代码已无错误运行
2012-12-21 11:10
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turorial 08源代码。
原始代码没有考虑视频和显示窗口大小不同的问题,会导致bug,
而自己又搞不明白到底是什么情况。
我对源代码做了一些修改,可以在VS上顺利编译通过并且无错运行。
av_seek_frame可能存在一些问题,目前不太清楚为什么经常出现错误
下面为修改好的源代码,可以直接编译:
原始代码没有考虑视频和显示窗口大小不同的问题,会导致bug,
而自己又搞不明白到底是什么情况。
我对源代码做了一些修改,可以在VS上顺利编译通过并且无错运行。
av_seek_frame可能存在一些问题,目前不太清楚为什么经常出现错误
下面为修改好的源代码,可以直接编译:
// tutorial08.c // A pedagogical video player that really works! Now with seeking features. // // Code based on FFplay, Copyright (c) 2003 Fabrice Bellard, // and a tutorial by Martin Bohme (boehme@inb.uni-luebeckREMOVETHIS.de) // Tested on Gentoo, CVS version 5/01/07 compiled with GCC 4.1.1 // Use // // gcc -o tutorial08 tutorial08.c -lavformat -lavcodec -lz -lm `sdl-config --cflags --libs` // to build (assuming libavformat and libavcodec are correctly installed, // and assuming you have sdl-config. Please refer to SDL docs for your installation.) // // Run using // tutorial08 myvideofile.mpg // // to play the video. // 2012-12-21 luofl 修改了因为视频大小与创建的窗口大小不一致带来的问题 // 解决方案是通过对视频图像进行缩放以适应窗口大小,见下面的修改代码 #include "avcodec.h" #include "avformat.h" #include "SDL/SDL.h" #include "SDL/SDL_thread.h" #include "swscale.h" #ifdef main #undef main /* Prevents SDL from overriding main() */ #endif #include <stdio.h> #pragma comment(linker,"/NODEFAULTLIB:libc.lib") #pragma comment(lib, "avcodec.lib") #pragma comment(lib, "avdevice.lib") #pragma comment(lib, "avfilter.lib") #pragma comment(lib, "avformat.lib") #pragma comment(lib, "swscale.lib") #pragma comment(lib, "avutil.lib") #pragma comment(lib, "postproc.lib") #pragma comment(lib, "swresample.lib") #pragma comment(lib, "SDL.lib") #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 ***_SYNC_THRESHOLD 0.01 #define ***_NOSYNC_THRESHOLD 10.0 #define SAMPLE_CORRECTION_PERCENT_MAX 10 #define AUDIO_DIFF_***G_NB 20 #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 #define DEFAULT_***_SYNC_TYPE ***_SYNC_VIDEO_MASTER typedef struct PacketQueue { ***PacketList *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; /* source height & width */ int allocated; double pts; } VideoPicture; typedef struct VideoState { ***FormatContext *pFormatCtx; int videoStream, audioStream; int av_sync_type; double external_clock; /* external clock base */ int64_t external_clock_time; int seek_req; int seek_flags; int64_t seek_pos; double audio_clock; ***Stream *audio_st; PacketQueue audioq; DECLARE_ALIGNED(16, uint8_t, audio_buf[(***CODEC_MAX_AUDIO_FRAME_SIZE * 3) / 2]); unsigned int audio_buf_size; unsigned int audio_buf_index; ***Packet audio_pkt; uint8_t *audio_pkt_data; int audio_pkt_size; int audio_hw_buf_size; double audio_diff_cum; /* used for *** difference average computation */ double audio_diff_avg_coef; double audio_diff_threshold; int audio_diff_avg_count; double frame_timer; double frame_last_pts; double frame_last_delay; double video_clock; ///<pts of last decoded frame / predicted pts of next decoded frame double video_current_pts; ///<current displayed pts (different from video_clock if frame fifos are used) int64_t video_current_pts_time; ///<time (av_gettime) at which we updated video_current_pts - used to have running video pts ***Stream *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; enum { ***_SYNC_AUDIO_MASTER, ***_SYNC_VIDEO_MASTER, ***_SYNC_EXTERNAL_MASTER, }; SDL_Surface *screen; /* Since we only have one decoding thread, the Big Struct can be global in case we need it. */ VideoState *global_video_state; ***Packet flush_pkt; long rint(double x) { if(x >= 0.) return (long)(x + 0.5); else return (long)(x - 0.5); } 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, ***Packet *pkt) { ***PacketList *pkt1; if(pkt != &flush_pkt && av_dup_packet(pkt) < 0) { return -1; } pkt1 = av_malloc(sizeof(***PacketList)); 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, ***Packet *pkt, int block) { ***PacketList *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; } static void packet_queue_flush(PacketQueue *q) { ***PacketList *pkt, *pkt1; SDL_LockMutex(q->mutex); for(pkt = q->first_pkt; pkt != NULL; pkt = pkt1) { pkt1 = pkt->next; av_free_packet(&pkt->pkt); av_freep(&pkt); } q->last_pkt = NULL; q->first_pkt = NULL; q->nb_packets = 0; q->size = 0; SDL_UnlockMutex(q->mutex); } double get_audio_clock(VideoState *is) { double pts; int hw_buf_size, bytes_per_sec, n; pts = is->audio_clock; /* maintained in the audio thread */ hw_buf_size = is->audio_buf_size - is->audio_buf_index; bytes_per_sec = 0; n = is->audio_st->codec->channels * 2; if(is->audio_st) { bytes_per_sec = is->audio_st->codec->sample_rate * n; } if(bytes_per_sec) { pts -= (double)hw_buf_size / bytes_per_sec; } return pts; } double get_video_clock(VideoState *is) { double delta; delta = (av_gettime() - is->video_current_pts_time) / 1000000.0; return is->video_current_pts + delta; } double get_external_clock(VideoState *is) { return av_gettime() / 1000000.0; } double get_master_clock(VideoState *is) { if(is->av_sync_type == ***_SYNC_VIDEO_MASTER) { return get_video_clock(is); } else if(is->av_sync_type == ***_SYNC_AUDIO_MASTER) { return get_audio_clock(is); } else { return get_external_clock(is); } } /* Add or subtract samples to get a better sync, return new audio buffer size */ int synchronize_audio(VideoState *is, short *samples, int samples_size, double pts) { int n; double ref_clock; n = 2 * is->audio_st->codec->channels; if(is->av_sync_type != ***_SYNC_AUDIO_MASTER) { double diff, avg_diff; int wanted_size, min_size, max_size, nb_samples; ref_clock = get_master_clock(is); diff = get_audio_clock(is) - ref_clock; if(diff < ***_NOSYNC_THRESHOLD) { // accumulate the diffs is->audio_diff_cum = diff + is->audio_diff_avg_coef * is->audio_diff_cum; if(is->audio_diff_avg_count < AUDIO_DIFF_***G_NB) { is->audio_diff_avg_count++; } else { avg_diff = is->audio_diff_cum * (1.0 - is->audio_diff_avg_coef); if(fabs(avg_diff) >= is->audio_diff_threshold) { wanted_size = samples_size + ((int)(diff * is->audio_st->codec->sample_rate) * n); min_size = samples_size * ((100 - SAMPLE_CORRECTION_PERCENT_MAX) / 100); max_size = samples_size * ((100 + SAMPLE_CORRECTION_PERCENT_MAX) / 100); if(wanted_size < min_size) { wanted_size = min_size; } else if (wanted_size > max_size) { wanted_size = max_size; } if(wanted_size < samples_size) { /* remove samples */ samples_size = wanted_size; } else if(wanted_size > samples_size) { uint8_t *samples_end, *q; int nb; /* add samples by copying final sample*/ nb = (samples_size - wanted_size); samples_end = (uint8_t *)samples + samples_size - n; q = samples_end + n; while(nb > 0) { memcpy(q, samples_end, n); q += n; nb -= n; } samples_size = wanted_size; } } } } else { /* difference is TOO big; reset diff stuff */ is->audio_diff_avg_count = 0; is->audio_diff_cum = 0; } } return samples_size; } int audio_decode_frame(VideoState *is, uint8_t *audio_buf, int buf_size, double *pts_ptr) { int len1, data_size, n; ***Packet *pkt = &is->audio_pkt; double pts; 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) { /* if error, skip frame */ is->audio_pkt_size = 0; break; } is->audio_pkt_data += len1; is->audio_pkt_size -= len1; if(data_size <= 0) { /* No data yet, get more frames */ continue; } pts = is->audio_clock; *pts_ptr = pts; n = 2 * is->audio_st->codec->channels; is->audio_clock += (double)data_size / (double)(n * is->audio_st->codec->sample_rate); /* We have data, return it and come back for more later */ return data_size; } if(pkt->data) av_free_packet(pkt); if(is->quit) { return -1; } /* next packet */ if(packet_queue_get(&is->audioq, pkt, 1) < 0) { return -1; } if(pkt->data == flush_pkt.data) { avcodec_flush_buffers(is->audio_st->codec); continue; } is->audio_pkt_data = pkt->data; is->audio_pkt_size = pkt->size; /* if update, update the audio clock w/pts */ if(pkt->pts != ***_NOPTS_VALUE) { is->audio_clock = av_q2d(is->audio_st->time_base) * pkt->pts; } } } void audio_callback(void *userdata, Uint8 *stream, int len) { VideoState *is = (VideoState *)userdata; int len1, audio_size; double pts; while(len > 0) { if(is->audio_buf_index >= is->audio_buf_size) { /* We have already sent all our data; get more */ audio_size = audio_decode_frame(is, is->audio_buf, sizeof(is->audio_buf), &pts); if(audio_size < 0) { /* If error, output silence */ is->audio_buf_size = 1024; memset(is->audio_buf, 0, is->audio_buf_size); } else { audio_size = synchronize_audio(is, (int16_t *)is->audio_buf, audio_size, pts); 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; /* 0 means stop timer */ } /* schedule a video refresh in 'delay' ms */ 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; ***Picture 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; } // apparently this assumption is bad #if 0 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; #else rect.x = 0; rect.y = 0; rect.w = screen->w; rect.h = screen->h; #endif SDL_LockYUVOverlay(vp->bmp); SDL_DisplayYUVOverlay(vp->bmp, &rect); SDL_UnlockYUVOverlay(vp->bmp); } } void video_refresh_timer(void *userdata) { VideoState *is = (VideoState *)userdata; VideoPicture *vp; double actual_delay, delay, sync_threshold, ref_clock, diff; if(is->video_st) { if(is->pictq_size == 0) { schedule_refresh(is, 1); } else { vp = &is->pictq[is->pictq_rindex]; is->video_current_pts = vp->pts; is->video_current_pts_time = av_gettime(); delay = vp->pts - is->frame_last_pts; /* the pts from last time */ if(delay <= 0 || delay >= 1.0) { /* if incorrect delay, use previous one */ delay = is->frame_last_delay; } /* save for next time */ is->frame_last_delay = delay; is->frame_last_pts = vp->pts; /* update delay to sync to audio if not master source */ if(is->av_sync_type != ***_SYNC_VIDEO_MASTER) { ref_clock = get_master_clock(is); diff = vp->pts - ref_clock; /* Skip or repeat the frame. Take delay into account FFPlay still doesn't "know if this is the best guess." */ sync_threshold = (delay > ***_SYNC_THRESHOLD) ? delay : ***_SYNC_THRESHOLD; if(fabs(diff) < ***_NOSYNC_THRESHOLD) { if(diff <= -sync_threshold) { delay = 0; } else if(diff >= sync_threshold) { delay = 2 * delay; } } } is->frame_timer += delay; /* computer the REAL delay */ actual_delay = is->frame_timer - (av_gettime() / 1000000.0); if(actual_delay < 0.010) { /* Really it should skip the picture instead */ actual_delay = 0.010; } schedule_refresh(is, (int)(actual_delay * 1000 + 0.5)); /* show the picture! */ video_display(is); /* update queue for next picture! */ 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) { // we already have one make another, bigger/smaller SDL_FreeYUVOverlay(vp->bmp); } // Allocate a place to put our YUV image on that screen #if 1 // 修改:这里按照窗口大小创建显示层,而不是根据视频的大小 vp->bmp = SDL_CreateYUVOverlay(screen->w, // is->video_st->codec->width, screen->h, // is->video_st->codec->height, #else vp->bmp = SDL_CreateYUVOverlay(is->video_st->codec->width, is->video_st->codec->height, #endif SDL_YV12_OVERLAY,// SDL_IYUV_OVERLAY、SDL_YV12_OVERLAY screen); #if 0 vp->width = is->video_st->codec->width; vp->height = is->video_st->codec->height; #else vp->width = screen->w; vp->height = screen->h; #endif SDL_LockMutex(is->pictq_mutex); vp->allocated = 1; SDL_CondSignal(is->pictq_cond); SDL_UnlockMutex(is->pictq_mutex); } int queue_picture(VideoState *is, ***Frame *pFrame, double pts) { VideoPicture *vp; int dst_pix_fmt; ***Picture pict; static struct SwsContext *img_convert_ctx; /* wait until we have space for a new pic */ 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; // windex is set to 0 initially vp = &is->pictq[is->pictq_windex]; /* allocate or resize the buffer! */ if(!vp->bmp || vp->width != is->video_st->codec->width || vp->height != is->video_st->codec->height) { SDL_Event event; vp->allocated = 0; /* we have to do it in the main thread */ event.type = FF_ALLOC_EVENT; event.user.data1 = is; SDL_PushEvent(&event); /* wait until we have a picture allocated */ 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; } } /* We have a place to put our picture on the queue */ /* If we are skipping a frame, do we set this to null but still return vp->allocated = 1? */ if(vp->bmp) { SDL_LockYUVOverlay(vp->bmp); dst_pix_fmt = PIX_FMT_YUV420P; /* point pict at the queue */ pict.data[0] = vp->bmp->pixels[0]; pict.data[1] = vp->bmp->pixels[2]; pict.data[2] = vp->bmp->pixels[1]; pict.data[3] = NULL; pict.linesize[0] = vp->bmp->pitches[0]; pict.linesize[1] = vp->bmp->pitches[2]; pict.linesize[2] = vp->bmp->pitches[1]; pict.linesize[3] = 0; // Convert the image into YUV format that SDL uses if(img_convert_ctx == NULL) { int w = is->video_st->codec->width; int h = is->video_st->codec->height; img_convert_ctx = sws_getContext(w, h, is->video_st->codec->pix_fmt, screen->w, screen->h, // 修改:同样这里按照窗口大小创建显示层,而不是根据视频的大小 dst_pix_fmt, SWS_BICUBIC, NULL, NULL, NULL); if(img_convert_ctx == NULL) { fprintf(stderr, "Cannot initialize the conversion context!\n"); exit(1); } } sws_scale(img_convert_ctx, pFrame->data, pFrame->linesize, 0, is->video_st->codec->height, pict.data, pict.linesize); SDL_UnlockYUVOverlay(vp->bmp); vp->pts = pts; /* now we inform our display thread that we have a pic ready */ 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; } double synchronize_video(VideoState *is, ***Frame *src_frame, double pts) { double frame_delay; if(pts != 0) { /* if we have pts, set video clock to it */ is->video_clock = pts; } else { /* if we aren't given a pts, set it to the clock */ pts = is->video_clock; } /* update the video clock */ frame_delay = av_q2d(is->video_st->codec->time_base); /* if we are repeating a frame, adjust clock accordingly */ frame_delay += src_frame->repeat_pict * (frame_delay * 0.5); is->video_clock += frame_delay; return pts; } uint64_t global_video_pkt_pts = ***_NOPTS_VALUE; /* These are called whenever we allocate a frame * buffer. We use this to store the global_pts in * a frame at the time it is allocated. */ int our_get_buffer(struct ***CodecContext *c, ***Frame *pic) { int ret = avcodec_default_get_buffer(c, pic); uint64_t *pts = av_malloc(sizeof(uint64_t)); *pts = global_video_pkt_pts; pic->opaque = pts; return ret; } void our_release_buffer(struct ***CodecContext *c, ***Frame *pic) { if(pic) av_freep(&pic->opaque); avcodec_default_release_buffer(c, pic); } int video_thread(void *arg) { VideoState *is = (VideoState *)arg; ***Packet pkt1, *packet = &pkt1; int len1, frameFinished; ***Frame *pFrame; double pts; pFrame = avcodec_alloc_frame(); for(;;) { if(packet_queue_get(&is->videoq, packet, 1) < 0) { // means we quit getting packets break; } if(packet->data == flush_pkt.data) { avcodec_flush_buffers(is->video_st->codec); continue; } pts = 0; // Save global pts to be stored in pFrame global_video_pkt_pts = packet->pts; // Decode video frame len1 = avcodec_decode_video(is->video_st->codec, pFrame, &frameFinished, packet->data, packet->size); if(packet->dts == ***_NOPTS_VALUE && pFrame->opaque && *(uint64_t *)pFrame->opaque != ***_NOPTS_VALUE) { pts = *(uint64_t *)pFrame->opaque; } else if(packet->dts != ***_NOPTS_VALUE) { pts = packet->dts; } else { pts = 0; } pts *= av_q2d(is->video_st->time_base); // Did we get a video frame? if(frameFinished) { pts = synchronize_video(is, pFrame, pts); if(queue_picture(is, pFrame, pts) < 0) { break; } } av_free_packet(packet); } av_free(pFrame); return 0; } int stream_component_open(VideoState *is, int stream_index) { ***FormatContext *pFormatCtx = is->pFormatCtx; ***CodecContext *codecCtx; ***Codec *codec; SDL_AudioSpec wanted_spec, spec; if(stream_index < 0 || stream_index >= pFormatCtx->nb_streams) { return -1; } // Get a pointer to the codec context for the video stream codecCtx = pFormatCtx->streams[stream_index]->codec; if(codecCtx->codec_type == CODEC_TYPE_AUDIO) { // Set audio settings from codec info 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; } is->audio_hw_buf_size = spec.size; } 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; /* averaging filter for audio sync */ is->audio_diff_avg_coef = exp(log(0.01 / AUDIO_DIFF_***G_NB)); is->audio_diff_avg_count = 0; /* Correct audio only if larger error than this */ is->audio_diff_threshold = 2.0 * SDL_AUDIO_BUFFER_SIZE / codecCtx->sample_rate; 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]; is->frame_timer = (double)av_gettime() / 1000000.0; is->frame_last_delay = 40e-3; is->video_current_pts_time = av_gettime(); packet_queue_init(&is->videoq); is->video_tid = SDL_CreateThread(video_thread, is); codecCtx->get_buffer = our_get_buffer; codecCtx->release_buffer = our_release_buffer; 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; ***FormatContext *pFormatCtx; ***Packet pkt1, *packet = &pkt1; int video_index = -1; int audio_index = -1; int i; is->videoStream = -1; is->audioStream = -1; global_video_state = is; // will interrupt blocking functions if we quit! url_set_interrupt_cb(decode_interrupt_cb); // Open video file if(av_open_input_file(&pFormatCtx, is->filename, NULL, 0, NULL) != 0) return -1; // Couldn't open file is->pFormatCtx = pFormatCtx; // Retrieve stream information if(av_find_stream_info(pFormatCtx) < 0) return -1; // Couldn't find stream information // Dump information about file onto standard error dump_format(pFormatCtx, 0, is->filename, 0); // Find the first video stream 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; } // main decode loop for(;;) { if(is->quit) { break; } // seek stuff goes here if(is->seek_req) { int stream_index = -1; int64_t seek_target = is->seek_pos; if (is->videoStream >= 0) stream_index = is->videoStream; else if(is->audioStream >= 0) stream_index = is->audioStream; if(stream_index >= 0) { ***Rational avRation = {1, ***_TIME_BASE}; seek_target = av_rescale_q(seek_target, avRation, pFormatCtx->streams[stream_index]->time_base); } if(!av_seek_frame(is->pFormatCtx, stream_index, seek_target, is->seek_flags)) { fprintf(stderr, "%s: error while seeking\n", is->pFormatCtx->filename); } else { if(is->audioStream >= 0) { packet_queue_flush(&is->audioq); packet_queue_put(&is->audioq, &flush_pkt); } if(is->videoStream >= 0) { packet_queue_flush(&is->videoq); packet_queue_put(&is->videoq, &flush_pkt); } } is->seek_req = 0; } 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); /* no error; wait for user input */ continue; } else { break; } } // Is this a packet from the video stream? 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); } } /* all done - wait for it */ while(!is->quit) { SDL_Delay(100); } fail: { SDL_Event event; event.type = FF_QUIT_EVENT; event.user.data1 = is; SDL_PushEvent(&event); } return 0; } void stream_seek(VideoState *is, int64_t pos, int rel) { if(!is->seek_req) { is->seek_pos = pos; is->seek_flags = rel < 0 ? ***SEEK_FLAG_BACKWARD : 0; is->seek_req = 1; } } int main(int argc, char *argv[]) { SDL_Event event; double pos; VideoState *is; is = av_mallocz(sizeof(VideoState)); if(argc < 2) { fprintf(stderr, "Usage: test <file>\n"); exit(1); } // Register all formats and codecs 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); } // Make a screen to put our video // 修改:这里是设置窗口大小,原始版本中没有考虑实际视频分辨率不是这么大的问题 // 所以原始代码播放其他大小的视频时出错 #ifndef __DARWIN__ screen = SDL_SetVideoMode(640, 480, 0, 0); #else screen = SDL_SetVideoMode(640, 480, 24, 0); #endif if(!screen) { fprintf(stderr, "SDL: could not set video mode - exiting\n"); exit(1); } strcpy(is->filename, argv[1]); is->pictq_mutex = SDL_CreateMutex(); is->pictq_cond = SDL_CreateCond(); schedule_refresh(is, 40); is->av_sync_type = DEFAULT_***_SYNC_TYPE; is->parse_tid = SDL_CreateThread(decode_thread, is); if(!is->parse_tid) { av_free(is); return -1; } av_init_packet(&flush_pkt); flush_pkt.data = "FLUSH"; for(;;) { double incr, pos; SDL_WaitEvent(&event); switch(event.type) { case SDL_KEYDOWN: switch(event.key.keysym.sym) { case SDLK_LEFT: incr = -1.0; goto do_seek; case SDLK_RIGHT: incr = 1.0; goto do_seek; case SDLK_UP: incr = 6.0; goto do_seek; case SDLK_DOWN: incr = -6.0; goto do_seek; do_seek: if(global_video_state) { pos = get_master_clock(global_video_state); pos += incr; stream_seek(global_video_state, (int64_t)(pos * ***_TIME_BASE), incr); } break; default: break; } break; case FF_QUIT_EVENT: case SDL_QUIT: is->quit = 1; SDL_Quit(); exit(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; }
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