打開設備
添加濾鏡
循環錄制文件
#include "libavdevice/avdevice.h"
#include "libavformat/avformat.h"
#include "libavcodec/avcodec.h"
#include "libavfilter/avfilter.h"
#include "libavfilter/buffersink.h"
#include "libavfilter/buffersrc.h"
#include "libswscale/swscale.h"
#include "libavutil/pixdesc.h"
#include "libavutil/hash.h"
#include "libavutil/bswap.h"
#include "libavutil/opt.h"
#include "libavutil/time.h"
#include "libavutil/timestamp.h"
#include "libavutil/pixfmt.h"
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>#define DEVICE_NAME "/dev/video0"
#define OUTPUT_FILE "/root/output.mp4"
#define DURATION_SEC 10 // 全局變量AVFormatContext *in_fmt_ctx = NULL, *out_fmt_ctx = NULL;
AVCodecContext *dec_ctx = NULL, *enc_ctx = NULL;
AVFilterGraph *filter_graph = NULL;
AVFilterContext *buffersrc_ctx = NULL, *buffersink_ctx = NULL;
AVStream *in_stream = NULL, *out_stream = NULL;AVCodecParameters *codecParameters = NULL;
int video_stream_index = -1;int init_input_output()
{AVDictionary *opts = NULL;AVInputFormat *input_fmt = av_find_input_format("v4l2");av_dict_set(&opts, "video_size", "640x480", 0);av_dict_set(&opts, "framerate", "25", 0);av_dict_set(&opts, "input_format", "mjpeg", 0);if (avformat_open_input(&in_fmt_ctx, DEVICE_NAME, input_fmt, &opts) < 0){fprintf(stderr, "無法打開輸入設忇\n");return -1;}if (avformat_find_stream_info(in_fmt_ctx, NULL) < 0){printf("open input failed\n");return -1;}video_stream_index = av_find_best_stream(in_fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, NULL);in_stream = in_fmt_ctx->streams[video_stream_index];codecParameters = in_stream->codecpar;printf("codecid = %d ; h = %d ; w = %d;\n", in_stream->codecpar->codec_id, codecParameters->height, codecParameters->width);AVCodec *decoder = avcodec_find_decoder(in_stream->codecpar->codec_id);if (!decoder){printf("upspoort decoder\n");return -1;}dec_ctx = avcodec_alloc_context3(decoder);avcodec_parameters_to_context(dec_ctx, codecParameters);if (avcodec_open2(dec_ctx, decoder, NULL) < 0){printf("decoder avcodec_open2 failed\n");return -1;}avformat_alloc_output_context2(&out_fmt_ctx, NULL, NULL, OUTPUT_FILE);const AVCodec *encoder = avcodec_find_encoder_by_name("mpeg4");; // avcodec_find_encoder(AV_CODEC_ID_H264);if (encoder == NULL){printf("unsporrt edcodec\n");return -1;}out_stream = avformat_new_stream(out_fmt_ctx, NULL);enc_ctx = avcodec_alloc_context3(encoder);enc_ctx->codec_type = AVMEDIA_TYPE_VIDEO;enc_ctx->codec_id = encoder->id;enc_ctx->width = 640;enc_ctx->height = 480;enc_ctx->pix_fmt = AV_PIX_FMT_YUV420P;enc_ctx->time_base = (AVRational){1, 25};enc_ctx->framerate = (AVRational){25, 1}; // in_stream->avg_frame_rate;//編碼幀率按照采集幀率板enc_ctx->has_b_frames = 0;enc_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;// av_opt_set(enc_ctx->priv_data, "tune", "zerolatency", 0);int ret = -1;ret = avcodec_open2(enc_ctx, encoder, NULL);printf("ret = %d\n", ret);if (ret < 0){printf(";;,,;encoder avcodec_open2 fialed\n");return -1;}out_stream->time_base = (AVRational){1, 25};avcodec_parameters_from_context(out_stream->codecpar, enc_ctx);if (!(out_fmt_ctx->oformat->flags & AVFMT_NOFILE)){avio_open(&out_fmt_ctx->pb, OUTPUT_FILE, AVIO_FLAG_WRITE);}avformat_write_header(out_fmt_ctx, NULL);return 0;
}
int init_filter_graph()
{if (!dec_ctx){printf("dec_ctx is nullptr\n");return -1;}printf("----------->init_filter_graph\n");char args[512] = {0};char filter_descr[512] = {0};filter_graph = avfilter_graph_alloc();if (!filter_graph){printf("filter_graph is nullptr\n");return -1;}const AVFilter *buffersrc = avfilter_get_by_name("buffer");const AVFilter *buffersink = avfilter_get_by_name("buffersink");if (!buffersrc || !buffersink){printf("buffersrc or buffersink is nullptr\n");return -1;}snprintf(args, sizeof(args), "video_size=640x480:pix_fmt=%d:time_base=1/25:pixel_aspect=1/1", dec_ctx->pix_fmt);avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in", args, NULL, filter_graph);avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out", NULL, NULL, filter_graph);enum AVPixelFormat pix_fmts[] = {AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE};if (av_opt_set_int_list(buffersink_ctx, "pix_fmts", pix_fmts, AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN) < 0){printf("set buufersink gesgi failed\n");}sprintf(filter_descr, "%s", "drawtext=fontfile=/usr/share/fonts/msyh.ttf:text='%{localtime\\:%Y-%m-%d %X}':fontcolor=white:fontsize=24:x=w-tw-10:y=10");// sprintf(filter_descr, "%s", "drawtext=fontfile=/usr/share/fonts/msyh.ttf:text='hello':fontcolor=white:fontsize=24:x=w-tw-10:y=10");// sprintf(filter_descr, "%s%s%s", "drawtext=fontfile=/usr/share/fonts/msyh.ttf:","text='%{localtime\:%Y-%m-%d %X}':","fontcolor=white:fontsize=24:x=w-tw-10:y=10");printf("text -> %s\n", filter_descr);AVFilterInOut *outputs = avfilter_inout_alloc();AVFilterInOut *inputs = avfilter_inout_alloc();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 (avfilter_graph_parse_ptr(filter_graph, filter_descr, &inputs, &outputs, NULL) < 0){return -1;}if (avfilter_graph_config(filter_graph, NULL) < 0){return -1;}avfilter_inout_free(&inputs);avfilter_inout_free(&outputs);return 0;
}
int process_and_encode()
{AVPacket pkt;AVFrame *frame = av_frame_alloc();AVFrame *filt_frame = av_frame_alloc();int64_t start_time = av_gettime();while (av_gettime() - start_time < DURATION_SEC * 1000000){if (av_read_frame(in_fmt_ctx, &pkt) >= 0 && pkt.stream_index == video_stream_index){avcodec_send_packet(dec_ctx, &pkt);while (avcodec_receive_frame(dec_ctx, frame) == 0){av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF);while (av_buffersink_get_frame(buffersink_ctx, filt_frame) >= 0){avcodec_send_frame(enc_ctx, filt_frame);while (avcodec_receive_packet(enc_ctx, &pkt) == 0){pkt.stream_index = out_stream->index;pkt.pts = av_rescale_q(pkt.pts, enc_ctx->time_base, out_stream->time_base);pkt.dts = av_rescale_q(pkt.dts, enc_ctx->time_base, out_stream->time_base);pkt.duration = av_rescale_q(pkt.duration, enc_ctx->time_base, out_stream->time_base);av_interleaved_write_frame(out_fmt_ctx, &pkt);av_packet_unref(&pkt);}av_frame_unref(filt_frame);}av_frame_unref(frame);}av_packet_unref(&pkt);}}av_frame_free(&frame);av_frame_free(&filt_frame);return 0;
}int process_and_encode1()
{AVPacket pkt;AVFrame *frame = av_frame_alloc();AVFrame *filt_frame = av_frame_alloc();int64_t start_time = av_gettime();int frame_count = 0; // 新忞：用于設置 filt_frame->ptswhile (frame_count <= 250){// 1. 從輸入迻取 packetif (av_read_frame(in_fmt_ctx, &pkt) >= 0 && pkt.stream_index == video_stream_index){// 2. 解碼avcodec_send_packet(dec_ctx, &pkt);while (avcodec_receive_frame(dec_ctx, frame) == 0){// 3. 送入濾鏡（忿 drawtext＿av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF);// 4. 從濾鏡輸鑿 filtered 帿while (av_buffersink_get_frame(buffersink_ctx, filt_frame) >= 0){// ? 顯式設置 filtered 幀的 PTS（避免編碼器無法計算時長＿filt_frame->pts = frame_count++;// 5. 編碼avcodec_send_frame(enc_ctx, filt_frame);while (1){AVPacket out_pkt;av_init_packet(&out_pkt);out_pkt.data = NULL;out_pkt.size = 0;if (avcodec_receive_packet(enc_ctx, &out_pkt) != 0){break; // 暫無叿寫入數據}// ? 轎換時間基（防歿不合泿 time_base 導致時長錯迿＿av_packet_rescale_ts(&out_pkt, enc_ctx->time_base, out_stream->time_base);out_pkt.stream_index = out_stream->index;av_interleaved_write_frame(out_fmt_ctx, &out_pkt);av_packet_unref(&out_pkt);}av_frame_unref(filt_frame);}av_frame_unref(frame);}av_packet_unref(&pkt);}}// ? 強制沖刷編碼器緩存（flush＿avcodec_send_frame(enc_ctx, NULL); // 通知編碼噿：結束了while (1){AVPacket out_pkt;av_init_packet(&out_pkt);out_pkt.data = NULL;out_pkt.size = 0;if (avcodec_receive_packet(enc_ctx, &out_pkt) != 0)break;av_packet_rescale_ts(&out_pkt, enc_ctx->time_base, out_stream->time_base);out_pkt.stream_index = out_stream->index;av_interleaved_write_frame(out_fmt_ctx, &out_pkt);av_packet_unref(&out_pkt);}av_frame_free(&frame);av_frame_free(&filt_frame);return 0;
}int main()
{printf("this is ffmpeg drawtext test mjpeg\n");av_register_all();avcodec_register_all();avdevice_register_all();avfilter_register_all();avformat_network_init();int ret = -1;ret = init_input_output();printf("reto = %d\n", ret);if (ret < 0){return -1;}ret = -1;ret = init_filter_graph();printf("ret1 = %d\n", ret);if (ret < 0){return -1;}ret = -1;ret = process_and_encode1();printf("ret2 = %d\n", ret);if (ret < 0){return -1;}// 清理資源av_write_trailer(out_fmt_ctx);if (!(out_fmt_ctx->oformat->flags & AVFMT_NOFILE)){avio_closep(&out_fmt_ctx->pb);avcodec_free_context(&dec_ctx);avcodec_free_context(&enc_ctx);avformat_close_input(&in_fmt_ctx);avformat_free_context(out_fmt_ctx);avfilter_graph_free(&filter_graph);}return 0;
}
