基于vs2017 vc++ ffmpeg4.0.2下测试
ffmpeg 环境配置请百度(vs2017 ffmpeg )
部分方法在https://blog.csdn.net/Java_lilin/article/details/85118365中查找
#include "pch.h"
#include <iostream>
extern "C" {
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavdevice/avdevice.h"
#include "libavutil/imgutils.h"
#include "libswscale/swscale.h"
#include "libswresample/swresample.h"
#include "libavutil/audio_fifo.h"
#include "libavutil/time.h"
#include "libavutil/opt.h"
#include "libavutil/mathematics.h"
#include "libavutil/channel_layout.h"
}
int main(){
AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL; //输入对应一个AVFormatContext,输出对应一个AVFormatContext
AVOutputFormat *ofmt = NULL;
AVPacket pkt;
const char *in_filename, *out_filename;
int ret, i;
int videoindex = -1;
int frame_index = 0;
int64_t start_time = 0;
in_filename = "C:\\Users\\lilin\\Desktop\\1.mp4";//输入URL
out_filename = "rtmp://192.168.0.108/live/f";//输出 URL[RTMP]
avformat_network_init();
//【2】 打开输入输入文件,获取视频索引号
if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0)
{
printf("Could not open input file.");
return -1;
}
if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0)
{
printf("Failed to retrieve input stream information");
return -1;
}
for (i = 0; i < ifmt_ctx->nb_streams; i++)
{
if (ifmt_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
{
videoindex = i;
break;
}
}
// 输出输入文件的格式信息
av_dump_format(ifmt_ctx, 0, in_filename, 0);
avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_filename); //RTMP
if (!ofmt_ctx)
{
printf("Could not create output context\n");
ret = AVERROR_UNKNOWN;
return -1;
}
ofmt = ofmt_ctx->oformat;
for (i = 0; i < ifmt_ctx->nb_streams; i++)
{
//根据输入流创建输出流
AVStream *in_stream = ifmt_ctx->streams[i];
AVCodec *incodec = avcodec_find_encoder(in_stream->codecpar->codec_id);
if (!incodec) {
printf("not found encoder 1 ");
return -1;
}
AVStream *out_stream = avformat_new_stream(ofmt_ctx, incodec);
if (!out_stream)
{
printf("Failed allocating output stream\n");
return -1;
}
//复制AVCodecContext的设置
AVCodecContext *codec_ctx = avcodec_alloc_context3(incodec);
ret = avcodec_parameters_to_context(codec_ctx, in_stream->codecpar);
if (ret < 0) {
printf("Failed to copy in_stream codecpar to codec context\n");
return -1;
}
codec_ctx->codec_tag = 0;
if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
codec_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
ret = avcodec_parameters_from_context(out_stream->codecpar, codec_ctx);
if (ret < 0) {
printf("Failed to copy codec context to out_stream codecpar context\n");
}
}
av_dump_format(ofmt_ctx, 0, out_filename, 1);
if (!(ofmt->flags & AVFMT_NOFILE))
{
ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
if (ret < 0)
{
printf("Could not open output URL '%s'", out_filename);
return -1;
}
}
//写文件头
ret = avformat_write_header(ofmt_ctx, NULL);
if (ret < 0)
{
printf("Error occurred when opening output URL\n");
return -1;
}
start_time = av_gettime();
while (1)
{
AVStream *in_stream, *out_stream;
//获取一个AVPacket
ret = av_read_frame(ifmt_ctx, &pkt);
if (ret < 0) break;
//设置 PTS
if (pkt.pts == AV_NOPTS_VALUE)
{
//原始两帧之间的时间
int64_t calc_duration = (double)AV_TIME_BASE / av_q2d(ifmt_ctx->streams[videoindex]->r_frame_rate);
//设置一帧的时间参数
AVRational time_base1 = ifmt_ctx->streams[videoindex]->time_base;
pkt.pts = (double)(frame_index*calc_duration) / (double)(av_q2d(time_base1)*AV_TIME_BASE);
pkt.dts = pkt.pts;
pkt.duration = (double)calc_duration / (double)(av_q2d(time_base1)*AV_TIME_BASE);
}
//帧延时
if (pkt.stream_index == videoindex)
{
AVRational time_base = ifmt_ctx->streams[videoindex]->time_base;
AVRational time_base_q = { 1, AV_TIME_BASE };
int64_t pts_time = av_rescale_q(pkt.pts, time_base, time_base_q); //显示的时间
int64_t now_time = av_gettime() - start_time;
if (pts_time > now_time)
av_usleep(pts_time - now_time);
}
in_stream = ifmt_ctx->streams[pkt.stream_index];
out_stream = ofmt_ctx->streams[pkt.stream_index];
//转换PTS/DTS
pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
pkt.pos = -1;
//Print to Screen
if (pkt.stream_index == videoindex)
{
printf("Send %8d video frames to output URL\n", frame_index);
frame_index++;
}
ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
if (ret < 0)
{
printf("Error muxing packet\n");
break;
}
av_packet_unref(&pkt);
}
//【5】写文件尾
av_write_trailer(ofmt_ctx);
avformat_close_input(&ifmt_ctx);
//【6】 关闭输出
if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE)) {
avio_close(ofmt_ctx->pb);
}
avformat_free_context(ofmt_ctx);
if (ret < 0 && ret != AVERROR_EOF)
{
printf("end Error occurred.\n");
return -1;
}
return 0;
}
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