本文主要是记录如何使用ffmpeg进行推流。
本文使用本地的flv视频文件，然后使用ffmpeg读取flv文件的每一帧数据，向指定的rtmp服务器进行推流，rtmp服务器的搭建见之前的文章https://www.jianshu.com/p/206c1a85e570
实现代码如下
- (void)pushStreamWithInputFilePath:(NSString *)inFilePath rtmpServerURL:(NSString *)rtmpServerURL {
AVOutputFormat *ofmt = NULL;
av_register_all();
avformat_network_init();
avcodec_register_all();
//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;
int64_t start_time=0;
NSString *home = inFilePath ;
const char *urlStr = [home cStringUsingEncoding:NSUTF8StringEncoding];
char *url = (char *)urlStr;
in_filename = url;// ‰»ÎURL£®Input file URL£©
//in_filename = "shanghai03_p.h264";
// out_filename = "rtmp://localhost:1935/mytv/room";
out_filename = "rtmp://192.168.0.100/mytv/room";
out_filename = [rtmpServerURL UTF8String];
// out_filename = "rtmp://localhost/publishlive/livestream";//
//out_filename = "rtp://233.233.233.233:6666";// ‰≥ˆ URL£®Output URL£©[UDP]
//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, "flv", out_filename); //RTMP
// avformat_alloc_output_context2(&ofmt_ctx, NULL, "mpegts", out_filename);//UDP
avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_filename);//UDP
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;
}
start_time=av_gettime();
while (1) {
AVStream *in_stream, *out_stream;
//Get an AVPacket
ret = av_read_frame(ifmt_ctx, &pkt);
if (ret < 0)
break;
//FIX£∫No PTS (Example: Raw H.264)
//Simple Write PTS
if(pkt.pts==AV_NOPTS_VALUE){
//Write PTS
AVRational time_base1=ifmt_ctx->streams[videoindex]->time_base;
//Duration between 2 frames (us)
int64_t calc_duration=(double)AV_TIME_BASE/av_q2d(ifmt_ctx->streams[videoindex]->r_frame_rate);
//Parameters
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);
}
//Important:Delay
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.dts, time_base, time_base_q);
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];
/* copy packet */
//Convert PTS/DTS
pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (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_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);
}
//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");
}
}
调用
NSString *inputFilePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"test1.flv"] ;
NSString *rtmpServerURL = @"rtmp://192.168.0.100/mytv/room";
[self pushStreamWithInputFilePath:inputFilePath rtmpServerURL:rtmpServerURL];
完整代码：
//
// ViewController.m
// FFmpegPushStream
//
// Created by bo jiang on 2022/6/12.
//
#import "ViewController.h"
#include <libavformat/avformat.h>
#include <libavutil/mathematics.h>
//#include <libavutil/mat>
#include <libavutil/mathematics.h>
#include <libavutil/version.h>
#include <libavutil/time.h>
#include <libavcodec/version.h>
#include <libavformat/version.h>
#include <libavdevice/version.h>
#include <libavfilter/version.h>
#include <libswscale/version.h>
#include <libswresample/version.h>
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
NSString *inputFilePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"test1.flv"] ;
NSString *rtmpServerURL = @"rtmp://192.168.0.100/mytv/room";
[self pushStreamWithInputFilePath:inputFilePath rtmpServerURL:rtmpServerURL];
}
- (void)pushStreamWithInputFilePath:(NSString *)inFilePath rtmpServerURL:(NSString *)rtmpServerURL {
AVOutputFormat *ofmt = NULL;
av_register_all();
avformat_network_init();
avcodec_register_all();
//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;
int64_t start_time=0;
NSString *home = inFilePath ;
const char *urlStr = [home cStringUsingEncoding:NSUTF8StringEncoding];
char *url = (char *)urlStr;
in_filename = url;// ‰»ÎURL£®Input file URL£©
//in_filename = "shanghai03_p.h264";
// out_filename = "rtmp://localhost:1935/mytv/room";
out_filename = "rtmp://192.168.0.100/mytv/room";
out_filename = [rtmpServerURL UTF8String];
// out_filename = "rtmp://localhost/publishlive/livestream";//
//out_filename = "rtp://233.233.233.233:6666";// ‰≥ˆ URL£®Output URL£©[UDP]
//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, "flv", out_filename); //RTMP
// avformat_alloc_output_context2(&ofmt_ctx, NULL, "mpegts", out_filename);//UDP
avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_filename);//UDP
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;
}
start_time=av_gettime();
while (1) {
AVStream *in_stream, *out_stream;
//Get an AVPacket
ret = av_read_frame(ifmt_ctx, &pkt);
if (ret < 0)
break;
//FIX£∫No PTS (Example: Raw H.264)
//Simple Write PTS
if(pkt.pts==AV_NOPTS_VALUE){
//Write PTS
AVRational time_base1=ifmt_ctx->streams[videoindex]->time_base;
//Duration between 2 frames (us)
int64_t calc_duration=(double)AV_TIME_BASE/av_q2d(ifmt_ctx->streams[videoindex]->r_frame_rate);
//Parameters
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);
}
//Important:Delay
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.dts, time_base, time_base_q);
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];
/* copy packet */
//Convert PTS/DTS
pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (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_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);
}
//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");
}
}
@end
