本文记录一个安卓平台下基于FFmpeg的视频推流器。该推流器C语言的源代码来自于《最简单的基于FFMPEG的推流器》。相关的概念就不再重复记录了。源代码项目的目录结构如图所示。Java源代码位于src目录，而C代码位于jni目录。
Android程序Java端代码位于src\com\leixiaohua1020\sffmpegandroidstreamer\MainActivity.java，如下所示。/** * 最简单的基于FFmpeg的推流器(RTMP)-安卓 * Simplest FFmpeg Android Streamer (RTMP) * * 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 * * * 本程序是安卓平台下最简单的基于FFmpeg的推流器。 * 它可以将视频文件以流媒体的形式推送到服务器。 * * This software is the simplest streamer based on FFmpeg in Android. * It can stream local media file to streaming media server (in RTMP). * */package com.leixiaohua1020.sffmpegandroidstreamer;import android.os.Bundle;import android.os.Environment;import android.app.Activity;import android.util.Log;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button startButton = (Button) this.findViewById(R.id.button_start);final EditText urlEdittext_input= (EditText) this.findViewById(R.id.input_url);final EditText urlEdittext_output= (EditText) this.findViewById(R.id.output_url);startButton.setOnClickListener(new OnClickListener() {public void onClick(View arg0){String folderurl=Environment.getExternalStorageDirectory().getPath();String urltext_input=urlEdittext_input.getText().toString();String inputurl=folderurl+"/"+urltext_input;String outputurl=urlEdittext_output.getText().toString();Log.e("inputurl",inputurl);Log.e("outputurl",outputurl);String info="";stream(inputurl,outputurl);Log.e("Info",info);}});}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}//JNIpublic native int stream(String inputurl, String outputurl);static{System.loadLibrary("avutil-54");System.loadLibrary("swresample-1");System.loadLibrary("avcodec-56");System.loadLibrary("avformat-56");System.loadLibrary("swscale-3");System.loadLibrary("postproc-53");System.loadLibrary("avfilter-5");System.loadLibrary("avdevice-56");System.loadLibrary("sffstreamer");}}C语言端源代码位于jni/simplest_ffmpeg_streamer.c，如下所示。/** * 最简单的基于FFmpeg的推流器-安卓 * Simplest FFmpeg Android 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 * * * 本程序是安卓平台下最简单的基于FFmpeg的流媒体推送器。 * 它可以将视频数据以流媒体的形式发送出去。 * * This software is the simplest streamer based on FFmpeg in Android. * It can stream local media file to streaming media server (in RTMP). */#include <stdio.h>#include <time.h> #include "libavcodec/avcodec.h"#include "libavformat/avformat.h"#include "libavutil/log.h"#ifdef ANDROID#include <jni.h>#include <android/log.h>#define LOGE(format, …) __android_log_print(ANDROID_LOG_ERROR, "(>_<)", format, ##__VA_ARGS__)#define LOGI(format, …) __android_log_print(ANDROID_LOG_INFO, "(^_^)", format, ##__VA_ARGS__)#else#define LOGE(format, …) printf("(>_<) " format "\n", ##__VA_ARGS__)#define LOGI(format, …) printf("(^_^) " format "\n", ##__VA_ARGS__)#endif//Output FFmpeg’s av_log()void custom_log(void *ptr, int level, const char* fmt, va_list vl){//To TXT fileFILE *fp=fopen("/storage/emulated/0/av_log.txt","a+");if(fp){vfprintf(fp,fmt,vl);fflush(fp);fclose(fp);}//To Logcat//LOGE(fmt, vl);}JNIEXPORT jint JNICALL Java_com_leixiaohua1020_sffmpegandroidstreamer_MainActivity_stream (JNIEnv *env, jobject obj, jstring input_jstr, jstring output_jstr){ AVOutputFormat *ofmt = NULL;AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;AVPacket pkt;int ret, i;char input_str[500]={0};char output_str[500]={0};char info[1000]={0};sprintf(input_str,"%s",(*env)->GetStringUTFChars(env,input_jstr, NULL));sprintf(output_str,"%s",(*env)->GetStringUTFChars(env,output_jstr, NULL));//input_str = "cuc_ieschool.flv";//output_str = "rtmp://localhost/publishlive/livestream";//output_str = "rtp://233.233.233.233:6666";//FFmpeg av_log() callbackav_log_set_callback(custom_log);av_register_all();//Networkavformat_network_init();//Inputif ((ret = avformat_open_input(&ifmt_ctx, input_str, 0, 0)) < 0) {LOGE( "Could not open input file.");goto end;}if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {LOGE( "Failed to retrieve input stream information");goto end;}int videoindex=-1;for(i=0; i<ifmt_ctx->nb_streams; i++) if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){videoindex=i;break;}//Outputavformat_alloc_output_context2(&ofmt_ctx, NULL, "flv",output_str); //RTMP//avformat_alloc_output_context2(&ofmt_ctx, NULL, "mpegts", output_str);//UDPif (!ofmt_ctx) {LOGE( "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 AVStreamAVStream *in_stream = ifmt_ctx->streams[i];AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);if (!out_stream) {LOGE( "Failed allocating output stream\n");ret = AVERROR_UNKNOWN;goto end;}//Copy the settings of AVCodecContextret = avcodec_copy_context(out_stream->codec, in_stream->codec);if (ret < 0) {LOGE( "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;}//Open output URLif (!(ofmt->flags & AVFMT_NOFILE)) {ret = avio_open(&ofmt_ctx->pb, output_str, AVIO_FLAG_WRITE);if (ret < 0) {LOGE( "Could not open output URL ‘%s’", output_str);goto end;}}//Write file headerret = avformat_write_header(ofmt_ctx, NULL);if (ret < 0) {LOGE( "Error occurred when opening output URL\n");goto end;}int frame_index=0;int64_t start_time=av_gettime();while (1) {AVStream *in_stream, *out_stream;//Get an AVPacketret = av_read_frame(ifmt_ctx, &pkt);if (ret < 0)break;//FIX：No PTS (Example: Raw H.264)//Simple Write PTSif(pkt.pts==AV_NOPTS_VALUE){//Write PTSAVRational 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);//Parameterspkt.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:Delayif(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/DTSpkt.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 Screenif(pkt.stream_index==videoindex){LOGE("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) {LOGE( "Error muxing packet\n");break;}av_free_packet(&pkt);}//Write file trailerav_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) {LOGE( "Error occurred.\n");return -1;}return 0;}Android.mk文件位于jni/Android.mk，如下所示。# Android.mk for FFmpeg## Lei Xiaohua 雷霄骅# leixiaohua1020@126.com# # LOCAL_PATH := $(call my-dir)# FFmpeg libraryinclude $(CLEAR_VARS)LOCAL_MODULE := avcodecLOCAL_SRC_FILES := libavcodec-56.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avdeviceLOCAL_SRC_FILES := libavdevice-56.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avfilterLOCAL_SRC_FILES := libavfilter-5.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avformatLOCAL_SRC_FILES := libavformat-56.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avutilLOCAL_SRC_FILES := libavutil-54.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := postprocLOCAL_SRC_FILES := libpostproc-53.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := swresampleLOCAL_SRC_FILES := libswresample-1.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := swscaleLOCAL_SRC_FILES := libswscale-3.soinclude $(PREBUILT_SHARED_LIBRARY)# Programinclude $(CLEAR_VARS)LOCAL_MODULE := sffstreamerLOCAL_SRC_FILES :=simplest_ffmpeg_streamer.cLOCAL_C_INCLUDES += $(LOCAL_PATH)/includeLOCAL_LDLIBS := -llog -lzLOCAL_SHARED_LIBRARIES := avcodec avdevice avfilter avformat avutil postproc swresample swscaleinclude $(BUILD_SHARED_LIBRARY)运行结果
App在手机上运行后的结果如下图所示。
注意需要把等待推送的视频文件拷贝至存储卡相应的目录中。例如对于上述截图的情况，，需要将sintel.mp4拷贝至存储卡的根目录中。
推流后的视频可以在电脑端使用ffplay接收，如下图所示。
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simplest ffmpeg mobile
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Github：https://github.com/leixiaohua1020/simplest_ffmpeg_mobile
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