ffmpeg 代码实现视频添加水印功能

备忘:

用ffmpeg给视频添加水印的命令为:

ffmpeg -i in.mp4 -i xxx.png -filter_complex "overlay=5:5"  out.mp4

代码实现如下, 主要是用了参考了ffmpeg.c里面的filter_complex的代码:

#include <unistd.h>#include <stdio.h>#include <assert.h>#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 <libswscale/swscale.h>const char *filter_descr = "overlay=5:5"; #define ENABLE_YUV_FILE 1AVFormatContext *input_fmt_ctx;AVCodecContext *input_dec_ctx;AVFormatContext *overlay_fmt_ctx;AVCodecContext *overlay_dec_ctx;int input_video_stream_idx, overlay_video_stream_idx;AVFilterGraph *filter_graph;AVFilterInOut *inputs;AVFilterInOut *outputs;AVFilterContext *buffersrc_ctx;AVFilterContext *bufferoverlay_ctx;AVFilterContext *buffersink_ctx;int ret;int got_frame;int video_eof_reached = 0;int overlay_eof_reached = 0;int active_stream_index = -1;FILE* fp_yuv;void yuv420p_save(AVFrame *pFrame);int video_transcode_step(AVFrame* mVideoFrame);int overlay_transcode_step(AVFrame* mOverlayFrame);int video_output_eof_packet(const char* tag, AVStream* ist, AVFilterContext* ifilter);static int open_input_file(const char *filename){    int ret;    AVCodec *dec;    if ((ret = avformat_open_input(&input_fmt_ctx, filename, NULL, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");        return ret;    }    if ((ret = avformat_find_stream_info(input_fmt_ctx, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");        return ret;    }    /* select the video stream */    ret = av_find_best_stream(input_fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0);    if (ret < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot find a video stream in the input file\n");        return ret;    }    input_video_stream_idx = ret;    input_dec_ctx = input_fmt_ctx->streams[input_video_stream_idx]->codec;    /* init the video decoder */    if ((ret = avcodec_open2(input_dec_ctx, dec, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot open video decoder\n");        return ret;    }    return 0;}static int open_overlay_file(const char *filename){    int ret;    AVCodec *dec;    if ((ret = avformat_open_input(&overlay_fmt_ctx, filename, NULL, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");        return ret;    }    if ((ret = avformat_find_stream_info(overlay_fmt_ctx, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");        return ret;    }    /* select the video stream */    ret = av_find_best_stream(overlay_fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0);    if (ret < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot find a video stream in the input file\n");        return ret;    }    overlay_video_stream_idx = ret;    overlay_dec_ctx = overlay_fmt_ctx->streams[overlay_video_stream_idx]->codec;    /* init the video decoder */    if ((ret = avcodec_open2(overlay_dec_ctx, dec, NULL)) < 0) {        av_log(NULL, AV_LOG_ERROR, "Cannot open video decoder\n");        return ret;    }    printf("overlay format = %s\n", overlay_fmt_ctx->iformat->name);    return 0;}static int video_config_input_filter(AVFilterInOut* inputs, AVFilterContext** input_filter_ctx){char args[512];memset(args, 0, sizeof(args));AVFilterContext *first_filter = inputs->filter_ctx;int pad_idx = inputs->pad_idx;AVFilter *filter = avfilter_get_by_name("buffer");//AVRational time_base = input_dec_ctx->time_base;AVStream* video_st = input_fmt_ctx->streams[input_video_stream_idx];AVRational time_base = video_st->time_base;snprintf(args, sizeof(args),            "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d:sws_param=flags=%d:frame_rate=%d/%d",            input_dec_ctx->width, input_dec_ctx->height, input_dec_ctx->pix_fmt,            input_dec_ctx->time_base.num, input_dec_ctx->time_base.den,            input_dec_ctx->sample_aspect_ratio.num, input_dec_ctx->sample_aspect_ratio.den,    SWS_BILINEAR + ((video_st->codec->flags&CODEC_FLAG_BITEXACT) ? SWS_BITEXACT:0),    video_st->r_frame_rate.num, video_st->r_frame_rate.den);       printf("input args = %s\n", args);ret = avfilter_graph_create_filter(input_filter_ctx, filter, "src_in", args, NULL, filter_graph);if (ret < 0 ) {printf("video config input filter fail.\n");return -1;}ret = avfilter_link(*input_filter_ctx, 0, first_filter, pad_idx);assert(ret >= 0);printf("video_config_input_filter avfilter_link ret = %d\n", ret);return ret;}static int video_config_overlay_filter(AVFilterInOut* inputs, AVFilterContext** overlay_filter_ctx ){char args[512];memset(args, 0, sizeof(args));AVFilterContext *first_filter = inputs->filter_ctx;int pad_idx = inputs->pad_idx;AVFilter *filter = avfilter_get_by_name("buffer");//AVRational time_base = overlay_dec_ctx->time_base;AVStream* overlay_st = overlay_fmt_ctx->streams[overlay_video_stream_idx];AVRational time_base = overlay_st->time_base;snprintf(args, sizeof(args),            "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d:sws_param=flags=%d:frame_rate=%d/%d",            overlay_dec_ctx->width, overlay_dec_ctx->height, overlay_dec_ctx->pix_fmt,            time_base.num, time_base.den,    overlay_dec_ctx->sample_aspect_ratio.num, overlay_dec_ctx->sample_aspect_ratio.den,    SWS_BILINEAR + ((overlay_st->codec->flags&CODEC_FLAG_BITEXACT) ? SWS_BITEXACT:0),            overlay_st->r_frame_rate.num, overlay_st->r_frame_rate.den);       printf("overlay args = %s\n", args);ret = avfilter_graph_create_filter(overlay_filter_ctx, filter, "overlay_in", args, NULL, filter_graph);if (ret < 0 ) {printf("video config overlay filter fail.\n");return -1;}ret = avfilter_link(*overlay_filter_ctx, 0, first_filter, pad_idx);assert(ret >= 0);printf("video_config_overlay_filter ret = %d\n", ret);avfilter_inout_free(&inputs);return ret;}static int video_config_output_filter(AVFilterInOut* outputs, AVFilterContext** out_filter_ctx){char args[512];AVFilterContext *last_filter = outputs->filter_ctx;int pad_idx  = outputs->pad_idx;AVFilter *buffersink = avfilter_get_by_name("ffbuffersink");int ret = avfilter_graph_create_filter(out_filter_ctx, buffersink, "video_out", NULL, NULL, filter_graph);assert(ret >= 0);if (ret < 0)return ret;ret = avfilter_link(last_filter, pad_idx, *out_filter_ctx, 0);assert(ret >= 0);if (ret < 0)return ret;avfilter_inout_free(&outputs);return 0;}static int init_input_filters(){filter_graph->scale_sws_opts = av_strdup("flags=0x4");        av_opt_set(filter_graph, "aresample_swr_opts", "", 0);ret = avfilter_graph_parse2(filter_graph, filter_descr, &inputs, &outputs);assert(inputs && inputs->next && !inputs->next->next);ret = video_config_input_filter(inputs, &buffersrc_ctx);ret = video_config_overlay_filter(inputs->next, &bufferoverlay_ctx);return ret;}static int init_output_filters(){return video_config_output_filter(outputs, &buffersink_ctx);}int reap_filters() {AVFilterBufferRef *picref;while (1) {ret = av_buffersink_get_buffer_ref(buffersink_ctx, &picref, AV_BUFFERSINK_FLAG_NO_REQUEST);if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {//printf("reap_filters fail ret = %d\n", ret);return 0; // no frame filtered.}printf("samplesref -------------------\n");AVFrame* filtered_frame = avcodec_alloc_frame();avcodec_get_frame_defaults(filtered_frame);avfilter_copy_buf_props(filtered_frame, picref);yuv420p_save(filtered_frame);avfilter_unref_bufferp(&picref);}}int transcode_from_filter(AVFilterContext** ifilters, int* eof_reached_arr, int* active_stream_indext) {int ret = 0;ret = avfilter_graph_request_oldest(filter_graph);if (ret >= 0) {return ret;        }if (ret == AVERROR_EOF) {return ret;}if (ret != AVERROR(EAGAIN)) {return ret;}int nb_requests_max = 0;int i;for (i = 0; i < 2; i++) {int eof_reached = eof_reached_arr[i];if (eof_reached) {continue;}AVFilterContext* ifilter = ifilters[i];int nb_requests = av_buffersrc_get_nb_failed_requests(ifilter);if (nb_requests > nb_requests_max) {    nb_requests_max = nb_requests;    *active_stream_indext = i;}}return ret;}int main(){avcodec_register_all();av_register_all();avfilter_register_all();avformat_network_init();char* video_file = "outFileSrc.mp4";char* overlay_video_file = "my_logo.png"; // light1.mp4 #if ENABLE_YUV_FILEconst char* yuvFile = "outWater.yuv";fp_yuv = fopen(yuvFile, "wb");#endifopen_input_file(video_file);open_overlay_file(overlay_video_file);filter_graph = avfilter_graph_alloc();if (!filter_graph) {printf("filter graph alloc fail.\n");return -1;}init_input_filters();init_output_filters();if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)            return ret;AVFrame* mVideoFrame = avcodec_alloc_frame();AVFrame* mOverlayFrame = avcodec_alloc_frame();while(1) {if (video_eof_reached && overlay_eof_reached) {            printf("stream EOF.\n");    break;}AVFilterContext* ifilters[] = {buffersrc_ctx, bufferoverlay_ctx};int eof_reacheds[] = {video_eof_reached, overlay_eof_reached};ret = transcode_from_filter(ifilters, eof_reacheds, &active_stream_index);if (ret >= 0) {ret = reap_filters();assert(ret >= 0);continue;        }if (ret == AVERROR_EOF) {ret = reap_filters();assert(ret >= 0);continue;}if (ret == AVERROR(EAGAIN) && active_stream_index < 0) {continue;}assert(active_stream_index >= 0);printf("active_stream_index = %d\n", active_stream_index);if (active_stream_index == 0) {video_transcode_step(mVideoFrame);continue;}overlay_transcode_step(mOverlayFrame);}if (input_dec_ctx)avcodec_close(input_dec_ctx);avformat_close_input(&input_fmt_ctx);if (overlay_dec_ctx)avcodec_close(overlay_dec_ctx);avformat_close_input(&overlay_fmt_ctx);printf("my_filtering_video3 end -------\n");return 0;}int video_transcode_step(AVFrame* mVideoFrame) {int ret = 0;AVPacket pkt;ret = av_read_frame(input_fmt_ctx, &pkt);if (ret == AVERROR(EAGAIN)) {return 0;}if (ret < 0) {video_eof_reached = 1;assert(ret == AVERROR_EOF);ret = video_output_eof_packet("video_eof", input_fmt_ctx->streams[input_video_stream_idx], buffersrc_ctx);assert (ret >= 0);return ret;}if (pkt.stream_index != input_video_stream_idx) {//av_free(&pkt);return ret;}ret = avcodec_decode_video2(input_dec_ctx, mVideoFrame, &got_frame, &pkt);if (ret < 0) {printf("Error decoding input video\n");}if (got_frame) {int64_t best_effort_timestamp = av_frame_get_best_effort_timestamp(mVideoFrame);    mVideoFrame->pts = best_effort_timestamp;if (av_buffersrc_add_frame(buffersrc_ctx, mVideoFrame, AV_BUFFERSRC_FLAG_PUSH) < 0) {av_log(NULL, AV_LOG_ERROR, "Error while feeding the video filtergraph\n");return -1;}reap_filters();}return 0;}int overlay_transcode_step(AVFrame* mOverlayFrame) {int ret = 0;AVPacket pkt;ret = av_read_frame(overlay_fmt_ctx, &pkt);if (ret == AVERROR(EAGAIN)) {return 0;}if (ret < 0) {overlay_eof_reached = 1;ret = video_output_eof_packet("overlay_eof", overlay_fmt_ctx->streams[input_video_stream_idx], bufferoverlay_ctx);assert(ret >=0 );return ret;}if (pkt.stream_index != overlay_video_stream_idx) {av_free_packet(&pkt);return ret;}ret = avcodec_decode_video2(overlay_dec_ctx, mOverlayFrame, &got_frame, &pkt);if (ret < 0) {printf("Error decoding overlay video\n");}if (got_frame) {int64_t best_effort_timestamp = av_frame_get_best_effort_timestamp(mOverlayFrame);    mOverlayFrame->pts = best_effort_timestamp;if (av_buffersrc_add_frame(bufferoverlay_ctx, mOverlayFrame, AV_BUFFERSRC_FLAG_PUSH) < 0) {av_log(NULL, AV_LOG_ERROR, "Error while feeding the audio filtergraph\n");return -1;}}return 0;}/*** output EOF packet to filter to flush*/int video_output_eof_packet(const char* tag, AVStream* ist, AVFilterContext* ifilter){    int ret = 0;        // alloc frame if NULL    AVFrame* decoded_frame = avcodec_alloc_frame();        AVPacket pkt;    av_init_packet(&pkt);    pkt.data = NULL;    pkt.size = 0;        int got_frame = 0;    ret = avcodec_decode_video2(ist->codec, decoded_frame, &got_frame, &pkt);    // EOF, assert got nothing and ret is 0.    // TODO: here we still got frame, different to ffmpeg.    assert(ret >= 0);        // flush filter    av_buffersrc_add_ref(ifilter, NULL, 0);        printf("[%s] filter -> eof packet.\n", tag);        return ret;}/**  * save yuv420p frame [YUV]  */  void yuv420p_save(AVFrame *pFrame)  {      int i = 0;        int width = pFrame->width, height = pFrame->height;      int height_half = height / 2, width_half = width / 2;      int y_wrap = pFrame->linesize[0];      int u_wrap = pFrame->linesize[1];      int v_wrap = pFrame->linesize[2];        unsigned char *y_buf = pFrame->data[0];      unsigned char *u_buf = pFrame->data[1];      unsigned char *v_buf = pFrame->data[2];        //save y      for (i = 0; i < height; i++)          fwrite(y_buf + i * y_wrap, 1, width, fp_yuv);      //save u      for (i = 0; i < height_half; i++)          fwrite(u_buf + i * u_wrap, 1, width_half, fp_yuv);      //save v      for (i = 0; i < height_half; i++)          fwrite(v_buf + i * v_wrap, 1, width_half, fp_yuv);        fflush(fp_yuv);  } 

PS: 用到avfilter的 ，如果有两个输入 ，不管音频还是视频， 代码基本都是这样 (如 视频的overlay   音频的amix 等等)