=====================================================
最简单的基于FFmpeg的移动端样例系列文章列表：
最简单的基于FFmpeg的移动端样例：Android HelloWorld
最简单的基于FFmpeg的移动端样例：Android 视频解码器
最简单的基于FFmpeg的移动端样例：Android 视频解码器-单个库版
最简单的基于FFmpeg的移动端样例：Android 推流器
最简单的基于FFmpeg的移动端样例：Android 视频转码器
最简单的基于FFmpeg的移动端样例附件：Android 自带播放器
最简单的基于FFmpeg的移动端样例附件：SDL Android HelloWorld
最简单的基于FFmpeg的移动端样例：IOS HelloWorld
最简单的基于FFmpeg的移动端样例：Windows Phone HelloWorld
=====================================================
本文记录IOS平台下基于FFmpeg的推流器。
该演示样例C语言的源码来自于《最简单的基于FFMPEG的推流器》。
相关的概念就不再反复记录了。
源码
项目的文件夹结构如图所看到的。
/**
* 最简单的基于FFmpeg的推流器-IOS
* Simplest FFmpeg IOS Streamer
*
* 雷霄骅 Lei Xiaohua
* leixiaohua1020@126.com
* 中国传媒大学/数字电视技术
* Communication University of China / Digital TV Technology
* http://blog.csdn.net/leixiaohua1020
*
* 本程序是IOS平台下的推流器。它能够将本地文件以流媒体的形式推送出去。
*
* This software is the simplest streamer in IOS.
* It can stream local media files to streaming media server.
*/
#import "ViewController.h"
#include <libavformat/avformat.h>
#include <libavutil/mathematics.h>
#include <libavutil/time.h>
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)clickStreamButton:(id)sender {
char input_str_full[500]={0};
char output_str_full[500]={0};
NSString *input_str= [NSString stringWithFormat:@"resource.bundle/%@",self.input.text];
NSString *input_nsstr=[[[NSBundle mainBundle]resourcePath] stringByAppendingPathComponent:input_str];
sprintf(input_str_full,"%s",[input_nsstr UTF8String]);
sprintf(output_str_full,"%s",[self.output.text UTF8String]);
printf("Input Path:%s
",input_str_full);
printf("Output Path:%s
",output_str_full);
AVOutputFormat *ofmt = NULL;
//Input AVFormatContext and Output AVFormatContext
AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
AVPacket pkt;
char in_filename[500]={0};
char out_filename[500]={0};
int ret, i;
int videoindex=-1;
int frame_index=0;
int64_t start_time=0;
//in_filename = "cuc_ieschool.mov";
//in_filename = "cuc_ieschool.h264";
//in_filename = "cuc_ieschool.flv";//Input file URL
//out_filename = "rtmp://localhost/publishlive/livestream";//Output URL[RTMP]
//out_filename = "rtp://233.233.233.233:6666";//Output URL[UDP]
strcpy(in_filename,input_str_full);
strcpy(out_filename,output_str_full);
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, "flv", out_filename); //RTMP
//avformat_alloc_output_context2(&ofmt_ctx, NULL, "mpegts", out_filename);//UDP
if (!ofmt_ctx) {
printf( "Could not create output context
");
ret = AVERROR_UNKNOWN;
goto end;
}
ofmt = ofmt_ctx->oformat;
for (i = 0; i < ifmt_ctx->nb_streams; i++) {
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
");
ret = AVERROR_UNKNOWN;
goto end;
}
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
");
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;
}
}
ret = avformat_write_header(ofmt_ctx, NULL);
if (ret < 0) {
printf( "Error occurred when opening output URL
");
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
",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
");
break;
}
av_free_packet(&pkt);
}
//写文件尾（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.
");
return;
}
return;
}
@end
执行结果
App在手机上执行后的结果例如以下图所看到的。单击“Stream”，将会把位于resource.bundle中的“war3end.mp4”文件推送到“rtmp://www.velab.com.cn/live/test”的URL上。
使用视频播放器（在这里使用ffplay）能够查看推送的实时流，例如以下图所看到的。
下载
simplest ffmpeg mobile
项目主页
Github：https://github.com/leixiaohua1020/simplest_ffmpeg_mobile
开源中国：https://git.oschina.net/leixiaohua1020/simplest_ffmpeg_mobile
SourceForge：https://sourceforge.net/projects/simplestffmpegmobile/
CSDN工程下载地址：http://download.csdn.net/detail/leixiaohua1020/8924391
[Android]
simplest_android_player: 基于安卓接口的视频播放器
simplest_ffmpeg_android_helloworld: 安卓平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_android_decoder: 安卓平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_android_decoder_onelib: 安卓平台下最简单的基于FFmpeg的视频解码器-单库版
simplest_ffmpeg_android_streamer: 安卓平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_android_transcoder: 安卓平台下移植的FFmpeg命令行工具
simplest_sdl_android_helloworld: 移植SDL到安卓平台的最简单程序
[IOS]
simplest_ios_player: 基于IOS接口的视频播放器
simplest_ffmpeg_ios_helloworld: IOS平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_ios_decoder: IOS平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_ios_streamer: IOS平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_ios_transcoder: IOS平台下移植的ffmpeg.c命令行工具
simplest_sdl_ios_helloworld: 移植SDL到IOS平台的最简单程序