// main.c
#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/opt.h> #include <libavutil/time.h> #include <libavutil/timestamp.h> #include <time.h> #include <stdio.h> #include <stdlib.h> #include <string.h>
#define WIDTH 640 #define HEIGHT 480 #define FPS 25 #define SEGMENT_DURATION 3600 // 1 hour
char *generate_filename() { time_t rawtime; struct tm *timeinfo; static char filename[256];
time(&rawtime);
timeinfo = localtime(&rawtime);
strftime(filename, sizeof(filename), "%Y-%m-%d_%H-%M-%S.mp4", timeinfo);
return filename;
}
AVFormatContext *open_input_device() { AVFormatContext *fmt_ctx = NULL; AVInputFormat *input_fmt = av_find_input_format("v4l2");
AVDictionary *options = NULL;
av_dict_set(&options, "input_format", "mjpeg", 0);
av_dict_set(&options, "framerate", "25", 0);
av_dict_set(&options, "video_size", "640x480", 0);
if (avformat_open_input(&fmt_ctx, "/dev/video0", input_fmt, &options) != 0) {
fprintf(stderr, "Could not open input device\n");
exit(1);
}
av_dict_free(&options);
return fmt_ctx;
}
AVCodecContext *open_decoder(AVStream *stream) { AVCodecContext *codec_ctx = avcodec_alloc_context3(NULL); avcodec_parameters_to_context(codec_ctx, stream->codecpar); AVCodec *decoder = avcodec_find_decoder(codec_ctx->codec_id); avcodec_open2(codec_ctx, decoder, NULL); return codec_ctx; }
AVFormatContext *open_output_context(const char *filename, AVCodecContext *dec_ctx, AVCodecContext **enc_ctx, AVStream **out_stream) { AVFormatContext *out_fmt_ctx; avformat_alloc_output_context2(&out_fmt_ctx, NULL, NULL, filename);
AVCodec *encoder = avcodec_find_encoder(AV_CODEC_ID_H264);
*enc_ctx = avcodec_alloc_context3(encoder);
(*enc_ctx)->height = dec_ctx->height;
(*enc_ctx)->width = dec_ctx->width;
(*enc_ctx)->pix_fmt = AV_PIX_FMT_YUV420P;
(*enc_ctx)->time_base = (AVRational){1, FPS};
avcodec_open2(*enc_ctx, encoder, NULL);
*out_stream = avformat_new_stream(out_fmt_ctx, encoder);
avcodec_parameters_from_context((*out_stream)->codecpar, *enc_ctx);
if (!(out_fmt_ctx->oformat->flags & AVFMT_NOFILE)) {
avio_open(&out_fmt_ctx->pb, filename, AVIO_FLAG_WRITE);
}
avformat_write_header(out_fmt_ctx, NULL);
return out_fmt_ctx;
}
void encode_and_write(AVFormatContext *out_fmt_ctx, AVCodecContext *enc_ctx, AVFrame *filt_frame) { AVPacket out_pkt; av_init_packet(&out_pkt); out_pkt.data = NULL; out_pkt.size = 0;
avcodec_send_frame(enc_ctx, filt_frame);
while (avcodec_receive_packet(enc_ctx, &out_pkt) == 0) {
out_pkt.stream_index = 0;
av_packet_rescale_ts(&out_pkt, enc_ctx->time_base, out_fmt_ctx->streams[0]->time_base);
av_inter