最简单的基于FFmpeg的AVFilter例子 1.2

/** * 最简单的基于FFmpeg的AVFilter例子（叠加水印） * Simplest FFmpeg AVfilter Example (Watermark) * * 雷霄骅 Lei Xiaohua * leixiaohua1020@126.com * 中国传媒大学/数字电视技术 * Communication University of China / Digital TV Technology * http://blog.csdn.net/leixiaohua1020 * * 本程序使用FFmpeg的AVfilter实现了视频的水印叠加功能。 * 可以将一张PNG图片作为水印叠加到视频上。 * 是最简单的FFmpeg的AVFilter方面的教程。 * 适合FFmpeg的初学者。 * * This software uses FFmpeg's AVFilter to add watermark in a video file. * It can add a PNG format picture as watermark to a video file. * It's the simplest example based on FFmpeg's AVFilter. * Suitable for beginner of FFmpeg * */ #include <stdio.h> #define __STDC_CONSTANT_MACROS #ifdef _WIN32 #define snprintf _snprintf //Windows extern "C" { #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" #include "libavfilter/avfiltergraph.h" #include "libavfilter/avcodec.h" #include "libavfilter/buffersink.h" #include "libavfilter/buffersrc.h" #include "libavutil/avutil.h" #include "libswscale/swscale.h" #include "SDL/SDL.h" }; #else //Linux... #ifdef __cplusplus extern "C" { #endif #include <libavcodec/avcodec.h> #include <libavformat/avformat.h> #include <libavfilter/avfiltergraph.h> #include <libavfilter/avcodec.h> #include <libavfilter/buffersink.h> #include <libavfilter/buffersrc.h> #include <libavutil/avutil.h> #include <libswscale/swscale.h> #include <SDL/SDL.h> #ifdef __cplusplus }; #endif #endif //Enable SDL? #define ENABLE_SDL 1 //Output YUV data? #define ENABLE_YUVFILE 1 const char *filter_descr = "movie=my_logo.png[wm];[in][wm]overlay=5:5[out]"; static AVFormatContext *pFormatCtx; static AVCodecContext *pCodecCtx; AVFilterContext *buffersink_ctx; AVFilterContext *buffersrc_ctx; AVFilterGraph *filter_graph; static int video_stream_index = -1; static int open_input_file(const char *filename) { int ret; AVCodec *dec; if ((ret = avformat_open_input(&pFormatCtx, filename, NULL, NULL)) < 0) { printf( "Cannot open input file\n"); return ret; } if ((ret = avformat_find_stream_info(pFormatCtx, NULL)) < 0) { printf( "Cannot find stream information\n"); return ret; } /* select the video stream */ ret = av_find_best_stream(pFormatCtx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0); if (ret < 0) { printf( "Cannot find a video stream in the input file\n"); return ret; } video_stream_index = ret; pCodecCtx = pFormatCtx->streams[video_stream_index]->codec; /* init the video decoder */ if ((ret = avcodec_open2(pCodecCtx, dec, NULL)) < 0) { printf( "Cannot open video decoder\n"); return ret; } return 0; } static int init_filters(const char *filters_descr) { char args[512]; int ret; AVFilter *buffersrc = avfilter_get_by_name("buffer"); AVFilter *buffersink = avfilter_get_by_name("ffbuffersink"); AVFilterInOut *outputs = avfilter_inout_alloc(); AVFilterInOut *inputs = avfilter_inout_alloc(); enum PixelFormat pix_fmts[] = { PIX_FMT_YUV420P, PIX_FMT_NONE }; AVBufferSinkParams *buffersink_params; filter_graph = avfilter_graph_alloc(); /* buffer video source: the decoded frames from the decoder will be inserted here. */ snprintf(args, sizeof(args), "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d", pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->time_base.num, pCodecCtx->time_base.den, pCodecCtx->sample_aspect_ratio.num, pCodecCtx->sample_aspect_ratio.den); ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in", args, NULL, filter_graph); if (ret < 0) { printf("Cannot create buffer source\n"); return ret; } /* buffer video sink: to terminate the filter chain. */ buffersink_params = av_buffersink_params_alloc(); buffersink_params->pixel_fmts = pix_fmts; ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out", NULL, buffersink_params, filter_graph); av_free(buffersink_params); if (ret < 0) { printf("Cannot create buffer sink\n"); return ret; } /* Endpoints for the filter graph. */ outputs->name = av_strdup("in"); outputs->filter_ctx = buffersrc_ctx; outputs->pad_idx = 0; outputs->next = NULL; inputs->name = av_strdup("out"); inputs->filter_ctx = buffersink_ctx; inputs->pad_idx = 0; inputs->next = NULL; if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr, &inputs, &outputs, NULL)) < 0) return ret; if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0) return ret; return 0; } int main(int argc, char* argv[]) { int ret; AVPacket packet; AVFrame frame; int got_frame; av_register_all(); avfilter_register_all(); if ((ret = open_input_file("cuc_ieschool.flv")) < 0) goto end; if ((ret = init_filters(filter_descr)) < 0) goto end; #if ENABLE_YUVFILE FILE *fp_yuv=fopen("test.yuv","wb+"); #endif #if ENABLE_SDL SDL_Surface *screen; SDL_Overlay *bmp; SDL_Rect rect; if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) { printf( "Could not initialize SDL - %s\n", SDL_GetError()); return -1; } screen = SDL_SetVideoMode(pCodecCtx->width, pCodecCtx->height, 0, 0); if(!screen) { printf("SDL: could not set video mode - exiting\n"); return -1; } bmp = SDL_CreateYUVOverlay(pCodecCtx->width, pCodecCtx->height,SDL_YV12_OVERLAY, screen); SDL_WM_SetCaption("Simplest FFmpeg Video Filter",NULL); #endif /* read all packets */ while (1) { AVFilterBufferRef *picref; ret = av_read_frame(pFormatCtx, &packet); if (ret< 0) break; if (packet.stream_index == video_stream_index) { avcodec_get_frame_defaults(&frame); got_frame = 0; ret = avcodec_decode_video2(pCodecCtx, &frame, &got_frame, &packet); if (ret < 0) { printf( "Error decoding video\n"); break; } if (got_frame) { frame.pts = av_frame_get_best_effort_timestamp(&frame); /* push the decoded frame into the filtergraph */ if (av_buffersrc_add_frame(buffersrc_ctx, &frame) < 0) { printf( "Error while feeding the filtergraph\n"); break; } /* pull filtered pictures from the filtergraph */ while (1) { ret = av_buffersink_get_buffer_ref(buffersink_ctx, &picref, 0); if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) break; if (ret < 0) goto end; if (picref) { #if ENABLE_YUVFILE //Y, U, V for(int i=0;i<picref->video->h;i++){ fwrite(picref->data[0]+picref->linesize[0]*i,1,picref->video->w,fp_yuv); } for(int i=0;i<picref->video->h/2;i++){ fwrite(picref->data[1]+picref->linesize[1]*i,1,picref->video->w/2,fp_yuv); } for(int i=0;i<picref->video->h/2;i++){ fwrite(picref->data[2]+picref->linesize[2]*i,1,picref->video->w/2,fp_yuv); } #endif #if ENABLE_SDL SDL_LockYUVOverlay(bmp); int y_size=picref->video->w*picref->video->h; memcpy(bmp->pixels[0],picref->data[0],y_size); //Y memcpy(bmp->pixels[2],picref->data[1],y_size/4); //U memcpy(bmp->pixels[1],picref->data[2],y_s