最简单的基于FFMPEG的推流器附件：收流器

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最简单的基于FFmpeg的推流器系列文章列表：

《最简单的基于FFmpeg的推流器（以推送RTMP为例）》

《最简单的基于FFMPEG的推流器附件：收流器》

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出于对《最简单的基于FFmpeg的推流器》的补充，本文记录一个最简单的基于FFmpeg的收流器。收流器和推流器的作用正好相反：推流器用于将本地文件以流媒体的形式发送出去，而收流器用于将流媒体内容保存为本地文件。

本文记录的推流器可以将RTMP流媒体保存成为一个本地的FLV文件。由于FFmpeg本身支持很多的流媒体协议和封装格式，所以也支持其它的封装格式和流媒体协议。

源代码

/**
* 最简单的基于FFmpeg的收流器（接收RTMP）
* Simplest FFmpeg Receiver (Receive RTMP)
*
* 雷霄骅 Lei Xiaohua
* [email protected]
* 中国传媒大学/数字电视技术
* Communication University of China / Digital TV Technology
* http://blog.csdn.net/leixiaohua1020
*
* 本例子将流媒体数据（以RTMP为例）保存成本地文件。
* 是使用FFmpeg进行流媒体接收最简单的教程。
*
* This example saves streaming media data (Use RTMP as example)
* as a local file.
* It's the simplest FFmpeg stream receiver.
*
*/

#include <stdio.h>

#define __STDC_CONSTANT_MACROS

#ifdef _WIN32
//Windows
extern "C"
{
#include "libavformat/avformat.h"
#include "libavutil/mathematics.h"
#include "libavutil/time.h"
};
#else
//Linux...
#ifdef __cplusplus
extern "C"
{
#endif
#include <libavformat/avformat.h>
#include <libavutil/mathematics.h>
#include <libavutil/time.h>
#ifdef __cplusplus
};
#endif
#endif

//'1': Use H.264 Bitstream Filter
#define USE_H264BSF 0

int main(int argc, char* argv[])
{
AVOutputFormat *ofmt = NULL;
//Input AVFormatContext and Output AVFormatContext
AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
AVPacket pkt;
const char *in_filename, *out_filename;
int ret, i;
int videoindex= -1;
int frame_index= 0;
in_filename = "rtmp://live.hkstv.hk.lxdns.com/live/hks";
//in_filename = "rtp://233.233.233.233:6666";
//out_filename = "receive.ts";
//out_filename = "receive.mkv";
out_filename = "receive.flv";

av_register_all();
//Network
avformat_network_init();
//Input
if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
printf( "Could not open input file.");
goto end;
}
if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
printf( "Failed to retrieve input stream information");
goto end;
}

for(i= 0; i<ifmt_ctx->nb_streams; i++)
if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
videoindex=i;
break;
}

av_dump_format(ifmt_ctx, 0, in_filename, 0);

//Output
avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename); //RTMP

if (!ofmt_ctx) {
printf( "Could not create output context\n");
ret = AVERROR_UNKNOWN;
goto end;
}
ofmt = ofmt_ctx->oformat;
for (i = 0; i < ifmt_ctx->nb_streams; i++) {
//Create output AVStream according to input AVStream
AVStream *in_stream = ifmt_ctx->streams[i];
AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
if (!out_stream) {
printf( "Failed allocating output stream\n");
ret = AVERROR_UNKNOWN;
goto end;
}
//Copy the settings of AVCodecContext
ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
if (ret < 0) {
printf( "Failed to copy context from input to output stream codec context\n");
goto end;
}
out_stream->codec->codec_tag = 0;
if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
//Dump Format------------------
av_dump_format(ofmt_ctx, 0, out_filename, 1);
//Open output URL
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);
goto end;
}
}
//Write file header
ret = avformat_write_header(ofmt_ctx, NULL);
if (ret < 0) {
printf( "Error occurred when opening output URL\n");
goto end;
}

#if USE_H264BSF
AVBitStreamFilterContext* h264bsfc = av_bitstream_filter_init( "h264_mp4toannexb");
#endif

while ( 1) {
AVStream *in_stream, *out_stream;
//Get an AVPacket
ret = av_read_frame(ifmt_ctx, &pkt);
if (ret < 0)
break;

in_stream = ifmt_ctx->streams[pkt.stream_index];
out_stream = ofmt_ctx->streams[pkt.stream_index];
/* copy packet */
//Convert 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( "Receive %8d video frames from input URL\n",frame_index);
frame_index++;

#if USE_H264BSF
av_bitstream_filter_filter(h264bsfc, in_stream->codec, NULL, &pkt.data, &pkt.size, pkt.data, pkt.size, 0);
#endif
}
//ret = av_write_frame(ofmt_ctx, &pkt);
ret = av_interleaved_write_frame(ofmt_ctx, &pkt);

if (ret < 0) {
printf( "Error muxing packet\n");
break;
}

av_free_packet(&pkt);

}

#if USE_H264BSF
av_bitstream_filter_close(h264bsfc);
#endif

//Write file trailer
av_write_trailer(ofmt_ctx);
end:
avformat_close_input(&ifmt_ctx);
/* close output */
if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
avio_close(ofmt_ctx->pb);
avformat_free_context(ofmt_ctx);
if (ret < 0 && ret != AVERROR_EOF) {
printf( "Error occurred.\n");
return -1;
}
return 0;
}

运行结果

程序运行之后，即可获取流媒体数据并且在本地保存成一个视频文件。

下载

simplest ffmpeg streamer

项目主页

SourceForge：https://sourceforge.net/projects/simplestffmpegstreamer/

Github：https://github.com/leixiaohua1020/simplest_ffmpeg_streamer

开源中国：http://git.oschina.net/leixiaohua1020/simplest_ffmpeg_streamer

CSDN下载地址：http://download.csdn.net/detail/leixiaohua1020/8924345

解决方案包含2个项目：

simplest_ffmpeg_streamer: 将本地视频文件推送至流媒体服务器。

simplest_ffmpeg_receiver: 将流媒体数据保存成本地文件。