ffmpeg超详细综合教程(三)——安卓手机摄像头编码
2015-12-30 11:01
471 查看
本文的示例将实现:读取安卓手机摄像头数据并使用H.264编码格式实时编码保存为flv文件。示例包含了
1、编译适用于安卓平台的ffmpeg库
2、在java中通过JNI使用ffmpeg
3、读取安卓摄像头数据并在后台线程中使用ffmpeg进行编码的基本流程
具有较强的综合性。
平时我们编译ffmpeg类库都是在x86平台下,而安卓手机属于arm平台,所以要先通过交叉编译的方法在x86平台下编译出可以在arm平台下使用的ffmpeg类库。Google就为我们提供了一套可以再Linux下完成该任务的交叉编译工具链——NDK,下载时可以看到google同时提供了ndk的windows版和linux版,前者可以在windows下通过cygwin(可以理解为一个在windows下模拟linux的工具)使用。我这里使用的是Android-ndk-r10e,在cygwin下使用。ndk的下载安装基本是傻瓜式的,但要注意linux系统对x86和x64是分的很清楚的,不像windows那么随性,此外还需要提醒的是,在下载安装cygwin时,只需要选择binutils
, gcc , gcc-mingw , gdb , make这几个组件。安装完成后,在cygwin安装目录下点击cygwin.bat打开命令窗口,输入make -version验证是否安装成功。
![](http://img.blog.csdn.net/20150920205515254?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center)
做好以上的准备工作之后就可以正式开始ffmpeg源码的编译了。
首先需要修改configure文件,确保类库版本号不会出现在.so后缀名的后面,否则安卓平台无法识别这样的类库
找到下面几句
[plain] view
plaincopy
SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)'
SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR)$(SLIBNAME)'
修改为
[plain] view
plaincopy
SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
SLIB_INSTALL_LINKS='$(SLIBNAME)'
之后进行常规的configure配置,make, make install步骤即可,下面给出一个常规的脚本示例
[plain] view
plaincopy
make clean
export NDK=xxxx/android-ndk-r10e
export PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.8/prebuilt
export PLATFORM=$NDK/platforms/android-8/arch-arm
export PREFIX=../android_ffmpeglib
./configure --target-os=linux --prefix=$PREFIX \
--enable-cross-compile \
--enable-runtime-cpudetect \
--disable-asm \
--arch=arm \
--cc=$PREBUILT/windows/bin/arm-linux-androideabi-gcc \
--cross-prefix=$PREBUILT/windows/bin/arm-linux-androideabi- \
--disable-stripping \
--nm=$PREBUILT/windows/bin/arm-linux-androideabi-nm \
--sysroot=$PLATFORM \
--enable-gpl --enable-shared --disable-static --enable-small \
--disable-ffprobe --disable-ffplay --disable-ffmpeg --disable-ffserver --disable-debug \
--extra-cflags="-fPIC -DANDROID -D__thumb__ -mthumb -Wfatal-errors -Wno-deprecated -mfloat-abi=softfp -marm -march=armv7-a"
make
make install
成功编译后,可以看到如下类库
![](http://img.blog.csdn.net/20150920211705223?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center)
JNI中的一些概念 :
-- native : Java语言中修饰本地方法的修饰符, 被该修饰符修饰的方法没有方法体;
-- Native方法 : 在Java语言中被native关键字修饰的方法是Native方法;
-- JNI层 : Java声明Native方法的部分;
-- JNI函数 : JNIEnv提供的函数, 这些函数在jni.h中进行定义;
-- JNI方法 : Native方法对应的JNI层实现的 C/C++方法, 即在jni目录中实现的那些C语言代码;
具体流程可以参照ndk的sample目录下的hellojni项目,总结起来有如下几个步骤
1、创建常规Android项目
2、声明Native方法,形如public native String stringFromJNI();
3、创建c文件
在工程根目录下创建 jni 目录, 然后创建一个c语言源文件, 在文件中引入 include <jni.h>。c语言方法声明形如
[cpp] view
plaincopy
jstring
Java_com_example_hellojni_HelloJni_stringFromJNI( JNIEnv* env,
jobject thiz )
jstring 是 Java语言中的String类型, 方法名格式为 : Java_完整包名类名_方法名();
-- JNIEnv参数 : 代表的是Java环境, 通过这个环境可以调用Java里面的方法;
-- jobject参数 : 调用C语言方法的对象, thiz对象表示当前的对象, 即调用JNI方法所在的类;
4、编写Android.mk文件
就好比常用的makefile,形如
[plain] view
plaincopy
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := hello-jni
LOCAL_SRC_FILES := hello-jni.c
include $(BUILD_SHARED_LIBRARY)
-- LOCAL_PATH : 代表mk文件所在的目录;
-- include $(CLEAR_VARS) : 编译工具函数, 通过该函数可以进行一些初始化操作;
-- LOCAL_MODULE : 编译后的 .so 后缀文件叫什么名字;
-- LOCAL_SRC_FILES: 指定编译的源文件名称;
-- include $(BUILD_SHARED_LIBRARY) : 告诉编译器需要生成动态库;
5、NDK编译生成动态库
利用上面写好的.mk文件,进入 cygdrive 找到windows目录下对应的文件, 编译完成之后, 会自动生成so文件并放在libs目录下, 之后就可以在Java中调用C语言方法了;
6、java中加载动态库
在Java类中的静态代码块中使用System.LoadLibrary()方法加载编译好的 .so 动态库,形如
[java] view
plaincopy
static {
System.loadLibrary("hello-jni");
}
需要说明的是,调试JNI程序非常麻烦,无法进入c文件中进行单步调试,只能通过输出一些信息然后利用logcat进行调试,所以也可以先在vs里面把c文件的内容跑一遍简单验证一下。
参照上面的基本流程,具体到利用ffmpeg实现安卓摄像头数据的编码
第一步:我们声明如下四个Native方法
[java] view
plaincopy
//JNI
//初始化,读取待编码数据的宽和高
public native int initial(int width,int height);
//读取yuv数据进行编码
public native int encode(byte[] yuvimage);
//清空缓存的帧
public native int flush();
//清理
public native int close();
第二步:对应的c文件内容如下,基本就是一个将yuv数据编码为H.264的flv文件的流程,唯一需要注意的就是安卓摄像头拍摄数据的像素格式为NV21,需要转换为YUV420P才能进行编码
[cpp] view
plaincopy
/**
* 基于FFmpeg安卓摄像头编码
* FFmpeg Android Camera Encoder
*
* 张晖 Hui Zhang
* zhanghuicuc@gmail.com
* 中国传媒大学/数字电视技术
* Communication University of China / Digital TV Technology
*
*
*/
#include <stdio.h>
#include <time.h>
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.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
***FormatContext *ofmt_ctx;
***Stream* video_st;
***CodecContext* pCodecCtx;
***Codec* pCodec;
***Packet enc_pkt;
***Frame *pFrameYUV;
int framecnt = 0;
int yuv_width;
int yuv_height;
int y_length;
int uv_length;
int64_t start_time;
//Output FFmpeg's av_log()
void custom_log(void *ptr, int level, const char* fmt, va_list vl){
FILE *fp=fopen("/storage/emulated/0/av_log.txt","a+");
if(fp){
vfprintf(fp,fmt,vl);
fflush(fp);
fclose(fp);
}
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_initial
(JNIEnv *env, jobject obj,jint width,jint height)
{
const char* out_path = "/sdcard/zhanghui/testffmpeg.flv";
yuv_width=width;
yuv_height=height;
y_length=width*height;
uv_length=width*height/4;
//FFmpeg av_log() callback
av_log_set_callback(custom_log);
av_register_all();
//output initialize
avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_path);
//output encoder initialize
pCodec = avcodec_find_encoder(***_CODEC_ID_H264);
if (!pCodec){
LOGE("Can not find encoder!\n");
return -1;
}
pCodecCtx = avcodec_alloc_context3(pCodec);
pCodecCtx->pix_fmt = PIX_FMT_YUV420P;
pCodecCtx->width = width;
pCodecCtx->height = height;
pCodecCtx->time_base.num = 1;
pCodecCtx->time_base.den = 30;
pCodecCtx->bit_rate = 800000;
pCodecCtx->gop_size = 300;
/* Some formats want stream headers to be separate. */
if (ofmt_ctx->oformat->flags & ***FMT_GLOBALHEADER)
pCodecCtx->flags |= CODEC_FLAG_GLOBAL_HEADER;
//H264 codec param
//pCodecCtx->me_range = 16;
//pCodecCtx->max_qdiff = 4;
//pCodecCtx->qcompress = 0.6;
pCodecCtx->qmin = 10;
pCodecCtx->qmax = 51;
//Optional Param
pCodecCtx->max_b_frames = 3;
// Set H264 preset and tune
***Dictionary *param = 0;
av_dict_set(¶m, "preset", "ultrafast", 0);
av_dict_set(¶m, "tune", "zerolatency", 0);
if (avcodec_open2(pCodecCtx, pCodec, ¶m) < 0){
LOGE("Failed to open encoder!\n");
return -1;
}
//Add a new stream to output,should be called by the user before avformat_write_header() for muxing
video_st = avformat_new_stream(ofmt_ctx, pCodec);
if (video_st == NULL){
return -1;
}
video_st->time_base.num = 1;
video_st->time_base.den = 30;
video_st->codec = pCodecCtx;
//Open output URL,set before avformat_write_header() for muxing
if (avio_open(&ofmt_ctx->pb, out_path, ***IO_FLAG_READ_WRITE) < 0){
LOGE("Failed to open output file!\n");
return -1;
}
//Write File Header
avformat_write_header(ofmt_ctx, NULL);
start_time = av_gettime();
return 0;
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_encode
(JNIEnv *env, jobject obj, jbyteArray yuv)
{
int ret;
int enc_got_frame=0;
int i=0;
pFrameYUV = avcodec_alloc_frame();
uint8_t *out_buffer = (uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));
avpicture_fill((***Picture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
//安卓摄像头数据为NV21格式,此处将其转换为YUV420P格式
jbyte* in= (jbyte*)(*env)->GetByteArrayElements(env,yuv,0);
memcpy(pFrameYUV->data[0],in,y_length);
for(i=0;i<uv_length;i++)
{
*(pFrameYUV->data[2]+i)=*(in+y_length+i*2);
*(pFrameYUV->data[1]+i)=*(in+y_length+i*2+1);
}
pFrameYUV->format = ***_PIX_FMT_YUV420P;
pFrameYUV->width = yuv_width;
pFrameYUV->height = yuv_height;
enc_pkt.data = NULL;
enc_pkt.size = 0;
av_init_packet(&enc_pkt);
ret = avcodec_encode_video2(pCodecCtx, &enc_pkt, pFrameYUV, &enc_got_frame);
av_frame_free(&pFrameYUV);
if (enc_got_frame == 1){
LOGI("Succeed to encode frame: %5d\tsize:%5d\n", framecnt, enc_pkt.size);
framecnt++;
enc_pkt.stream_index = video_st->index;
//Write PTS
***Rational time_base = ofmt_ctx->streams[0]->time_base;//{ 1, 1000 };
***Rational r_framerate1 = {60, 2 };//{ 50, 2 };
***Rational time_base_q = { 1, ***_TIME_BASE };
//Duration between 2 frames (us)
int64_t calc_duration = (double)(***_TIME_BASE)*(1 / av_q2d(r_framerate1)); //内部时间戳
//Parameters
//enc_pkt.pts = (double)(framecnt*calc_duration)*(double)(av_q2d(time_base_q)) / (double)(av_q2d(time_base));
enc_pkt.pts = av_rescale_q(framecnt*calc_duration, time_base_q, time_base);
enc_pkt.dts = enc_pkt.pts;
enc_pkt.duration = av_rescale_q(calc_duration, time_base_q, time_base); //(double)(calc_duration)*(double)(av_q2d(time_base_q)) / (double)(av_q2d(time_base));
enc_pkt.pos = -1;
//Delay
int64_t pts_time = av_rescale_q(enc_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);
ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
av_free_packet(&enc_pkt);
}
return 0;
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_flush
(JNIEnv *env, jobject obj)
{
int ret;
int got_frame;
***Packet enc_pkt;
if (!(ofmt_ctx->streams[0]->codec->codec->capabilities &
CODEC_CAP_DELAY))
return 0;
while (1) {
enc_pkt.data = NULL;
enc_pkt.size = 0;
av_init_packet(&enc_pkt);
ret = avcodec_encode_video2(ofmt_ctx->streams[0]->codec, &enc_pkt,
NULL, &got_frame);
if (ret < 0)
break;
if (!got_frame){
ret = 0;
break;
}
LOGI("Flush Encoder: Succeed to encode 1 frame!\tsize:%5d\n", enc_pkt.size);
//Write PTS
***Rational time_base = ofmt_ctx->streams[0]->time_base;//{ 1, 1000 };
***Rational r_framerate1 = { 60, 2 };
***Rational time_base_q = { 1, ***_TIME_BASE };
//Duration between 2 frames (us)
int64_t calc_duration = (double)(***_TIME_BASE)*(1 / av_q2d(r_framerate1)); //内部时间戳
//Parameters
enc_pkt.pts = av_rescale_q(framecnt*calc_duration, time_base_q, time_base);
enc_pkt.dts = enc_pkt.pts;
enc_pkt.duration = av_rescale_q(calc_duration, time_base_q, time_base);
//转换PTS/DTS(Convert PTS/DTS)
enc_pkt.pos = -1;
framecnt++;
ofmt_ctx->duration = enc_pkt.duration * framecnt;
/* mux encoded frame */
ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
if (ret < 0)
break;
}
//Write file trailer
av_write_trailer(ofmt_ctx);
return 0;
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_close
(JNIEnv *env, jobject obj)
{
if (video_st)
avcodec_close(video_st->codec);
avio_close(ofmt_ctx->pb);
avformat_free_context(ofmt_ctx);
return 0;
}
第三步:编写Android.mk如下,这里要在jni目录下放入ffmpeg的头文件,就跟平时的调用方法一样
[plain] view
plaincopy
LOCAL_PATH := $(call my-dir)
# FFmpeg library
include $(CLEAR_VARS)
LOCAL_MODULE := avcodec
LOCAL_SRC_FILES := libavcodec-56.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avdevice
LOCAL_SRC_FILES := libavdevice-56.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avfilter
LOCAL_SRC_FILES := libavfilter-5.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avformat
LOCAL_SRC_FILES := libavformat-56.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avutil
LOCAL_SRC_FILES := libavutil-54.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := postproc
LOCAL_SRC_FILES := libpostproc-53.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := swresample
LOCAL_SRC_FILES := libswresample-1.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := swscale
LOCAL_SRC_FILES := libswscale-3.so
include $(PREBUILT_SHARED_LIBRARY)
# Program
include $(CLEAR_VARS)
LOCAL_MODULE := encode
LOCAL_SRC_FILES :=encode.c
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
LOCAL_LDLIBS := -llog -lz
LOCAL_SHARED_LIBRARIES := avcodec avdevice avfilter avformat avutil postproc swresample swscale
include $(BUILD_SHARED_LIBRARY)
第四步:使用cygwin切换到当前项目的jni目录下,输入ndk-build进行编译即可,如下
![](http://img.blog.csdn.net/20150920221826160?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center)
此时就可以在当前项目的libs目录下看到ffmpeg所有的类库以及我们自己的类库,我这里是libencode.so,如下
![](http://img.blog.csdn.net/20150920222202787?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center)
第五步:在java中加载动态库
[java] view
plaincopy
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("encode");
}
至此,就可以在java中调用我们声明的四个方法了。
简单来说,就是利用Camera的PreviewCallback获得摄像头数据,在通过AsyncTask开启后台线程将摄像头数据进行编码。这里为了避免编码过程占用过多的硬件资源,将编码视频宽和高设置为了640和480,。
这里有两个坑,一是onPreviewFrame方法的arg0参数就是YUV数据了,不要再转换为YuvImage对象了,否则会在头部加上一些多余的信息,导致编码错误,二是用于清空缓存帧的flush方法不能在oncreate主线程中调用,否则会导致程序闪退,目前还不清楚原因,所以这里连同close()方法一起放到了onPause方法中进行调用,在安卓开发方面我还是新手,希望有了解这个问题怎么解决的朋友多多指教。
[java] view
plaincopy
package com.zhanghui.test;
import java.io.IOException;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
@SuppressWarnings("deprecation")
public class MainActivity extends Activity {
private static final String TAG= "MainActivity";
private Button mTakeButton;
private Camera mCamera;
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private boolean isRecording = false;
private class StreamTask extends AsyncTask<Void, Void, Void>{
private byte[] mData;
//构造函数
StreamTask(byte[] data){
this.mData = data;
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
if(mData!=null){
Log.i(TAG, "fps: " + mCamera.getParameters().getPreviewFrameRate());
encode(mData);
}
return null;
}
}
private StreamTask mStreamTask;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Camera.PreviewCallback mPreviewCallbacx=new Camera.PreviewCallback() {
@Override
public void onPreviewFrame(byte[] arg0, Camera arg1) {
// TODO Auto-generated method stub
if(null != mStreamTask){
switch(mStreamTask.getStatus()){
case RUNNING:
return;
case PENDING:
mStreamTask.cancel(false);
break;
}
}
mStreamTask = new StreamTask(arg0);
mStreamTask.execute((Void)null);
}
};
mTakeButton=(Button)findViewById(R.id.take_button);
PackageManager pm=this.getPackageManager();
boolean hasCamera=pm.hasSystemFeature(PackageManager.FEATURE_CAMERA) ||
pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT) ||
Build.VERSION.SDK_INT<Build.VERSION_CODES.GINGERBREAD;
if(!hasCamera)
mTakeButton.setEnabled(false);
mTakeButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(mCamera!=null)
{
if (isRecording) {
mTakeButton.setText("Start");
mCamera.setPreviewCallback(null);
Toast.makeText(MainActivity.this, "encode done", Toast.LENGTH_SHORT).show();
isRecording = false;
}else {
mTakeButton.setText("Stop");
initial(mCamera.getParameters().getPreviewSize().width,mCamera.getParameters().getPreviewSize().height);
mCamera.setPreviewCallback(mPreviewCallbacx);
isRecording = true;
}
}
}
});
mSurfaceView=(SurfaceView)findViewById(R.id.surfaceView1);
SurfaceHolder holder=mSurfaceView.getHolder();
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
holder.addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
if(mCamera!=null)
{
mCamera.stopPreview();
mSurfaceView = null;
mSurfaceHolder = null;
}
}
@Override
public void surfaceCreated(SurfaceHolder arg0) {
// TODO Auto-generated method stub
try{
if(mCamera!=null){
mCamera.setPreviewDisplay(arg0);
mSurfaceHolder=arg0;
}
}catch(IOException exception){
Log.e(TAG, "Error setting up preview display", exception);
}
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
if(mCamera==null) return;
Camera.Parameters parameters=mCamera.getParameters();
parameters.setPreviewSize(640,480);
parameters.setPictureSize(640,480);
mCamera.setParameters(parameters);
try{
mCamera.startPreview();
mSurfaceHolder=arg0;
}catch(Exception e){
Log.e(TAG, "could not start preview", e);
mCamera.release();
mCamera=null;
}
}
});
}
@TargetApi(9)
@Override
protected void onResume(){
super.onResume();
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.GINGERBREAD){
mCamera=Camera.open(0);
}else
{
mCamera=Camera.open();
}
}
@Override
protected void onPause(){
super.onPause();
flush();
close();
if(mCamera!=null){
mCamera.release();
mCamera=null;
}
}
@Override
public 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;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
//JNI
public native int initial(int width,int height);
public native int encode(byte[] yuvimage);
public native int flush();
public native int close();
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("encode");
}
}
至此,就完成了全部功能的开发,程序截图如下
首先由用户按下take键开始摄像
![](http://img.blog.csdn.net/20150920225452250?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center)
此时按键转为stop,按下即可停止摄像
![](http://img.blog.csdn.net/20150920225513777?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center)
按下stop后,即停止摄像,弹出encode done信息,退出程序即可在对应目录下看到编码的flv视频
![](http://img.blog.csdn.net/20150920225532640?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center)
项目源代码下载地址
github地址
https://github.com/zhanghuicuc/FFmpegAndroidCameraEncoder
来自:http://blog.csdn.net/nonmarking/article/details/48601317
1、编译适用于安卓平台的ffmpeg库
2、在java中通过JNI使用ffmpeg
3、读取安卓摄像头数据并在后台线程中使用ffmpeg进行编码的基本流程
具有较强的综合性。
编译适用于安卓平台的ffmpeg库
平时我们编译ffmpeg类库都是在x86平台下,而安卓手机属于arm平台,所以要先通过交叉编译的方法在x86平台下编译出可以在arm平台下使用的ffmpeg类库。Google就为我们提供了一套可以再Linux下完成该任务的交叉编译工具链——NDK,下载时可以看到google同时提供了ndk的windows版和linux版,前者可以在windows下通过cygwin(可以理解为一个在windows下模拟linux的工具)使用。我这里使用的是Android-ndk-r10e,在cygwin下使用。ndk的下载安装基本是傻瓜式的,但要注意linux系统对x86和x64是分的很清楚的,不像windows那么随性,此外还需要提醒的是,在下载安装cygwin时,只需要选择binutils, gcc , gcc-mingw , gdb , make这几个组件。安装完成后,在cygwin安装目录下点击cygwin.bat打开命令窗口,输入make -version验证是否安装成功。
做好以上的准备工作之后就可以正式开始ffmpeg源码的编译了。
首先需要修改configure文件,确保类库版本号不会出现在.so后缀名的后面,否则安卓平台无法识别这样的类库
找到下面几句
[plain] view
plaincopy
SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)'
SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR)$(SLIBNAME)'
修改为
[plain] view
plaincopy
SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
SLIB_INSTALL_LINKS='$(SLIBNAME)'
之后进行常规的configure配置,make, make install步骤即可,下面给出一个常规的脚本示例
[plain] view
plaincopy
make clean
export NDK=xxxx/android-ndk-r10e
export PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.8/prebuilt
export PLATFORM=$NDK/platforms/android-8/arch-arm
export PREFIX=../android_ffmpeglib
./configure --target-os=linux --prefix=$PREFIX \
--enable-cross-compile \
--enable-runtime-cpudetect \
--disable-asm \
--arch=arm \
--cc=$PREBUILT/windows/bin/arm-linux-androideabi-gcc \
--cross-prefix=$PREBUILT/windows/bin/arm-linux-androideabi- \
--disable-stripping \
--nm=$PREBUILT/windows/bin/arm-linux-androideabi-nm \
--sysroot=$PLATFORM \
--enable-gpl --enable-shared --disable-static --enable-small \
--disable-ffprobe --disable-ffplay --disable-ffmpeg --disable-ffserver --disable-debug \
--extra-cflags="-fPIC -DANDROID -D__thumb__ -mthumb -Wfatal-errors -Wno-deprecated -mfloat-abi=softfp -marm -march=armv7-a"
make
make install
成功编译后,可以看到如下类库
在java中通过JNI使用ffmpeg
JNI即java本地接口,java native interface,它是一个协议, 该协议用来沟通Java代码和外部的本地C/C++代码, 通过该协议 Java代码可以调用外部的本地代码, 外部的C/C++ 代码可以调用Java代码。简单来说,就是将一个C语言的方法映射到Java的某个方法上;JNI中的一些概念 :
-- native : Java语言中修饰本地方法的修饰符, 被该修饰符修饰的方法没有方法体;
-- Native方法 : 在Java语言中被native关键字修饰的方法是Native方法;
-- JNI层 : Java声明Native方法的部分;
-- JNI函数 : JNIEnv提供的函数, 这些函数在jni.h中进行定义;
-- JNI方法 : Native方法对应的JNI层实现的 C/C++方法, 即在jni目录中实现的那些C语言代码;
具体流程可以参照ndk的sample目录下的hellojni项目,总结起来有如下几个步骤
1、创建常规Android项目
2、声明Native方法,形如public native String stringFromJNI();
3、创建c文件
在工程根目录下创建 jni 目录, 然后创建一个c语言源文件, 在文件中引入 include <jni.h>。c语言方法声明形如
[cpp] view
plaincopy
jstring
Java_com_example_hellojni_HelloJni_stringFromJNI( JNIEnv* env,
jobject thiz )
jstring 是 Java语言中的String类型, 方法名格式为 : Java_完整包名类名_方法名();
-- JNIEnv参数 : 代表的是Java环境, 通过这个环境可以调用Java里面的方法;
-- jobject参数 : 调用C语言方法的对象, thiz对象表示当前的对象, 即调用JNI方法所在的类;
4、编写Android.mk文件
就好比常用的makefile,形如
[plain] view
plaincopy
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := hello-jni
LOCAL_SRC_FILES := hello-jni.c
include $(BUILD_SHARED_LIBRARY)
-- LOCAL_PATH : 代表mk文件所在的目录;
-- include $(CLEAR_VARS) : 编译工具函数, 通过该函数可以进行一些初始化操作;
-- LOCAL_MODULE : 编译后的 .so 后缀文件叫什么名字;
-- LOCAL_SRC_FILES: 指定编译的源文件名称;
-- include $(BUILD_SHARED_LIBRARY) : 告诉编译器需要生成动态库;
5、NDK编译生成动态库
利用上面写好的.mk文件,进入 cygdrive 找到windows目录下对应的文件, 编译完成之后, 会自动生成so文件并放在libs目录下, 之后就可以在Java中调用C语言方法了;
6、java中加载动态库
在Java类中的静态代码块中使用System.LoadLibrary()方法加载编译好的 .so 动态库,形如
[java] view
plaincopy
static {
System.loadLibrary("hello-jni");
}
需要说明的是,调试JNI程序非常麻烦,无法进入c文件中进行单步调试,只能通过输出一些信息然后利用logcat进行调试,所以也可以先在vs里面把c文件的内容跑一遍简单验证一下。
参照上面的基本流程,具体到利用ffmpeg实现安卓摄像头数据的编码
第一步:我们声明如下四个Native方法
[java] view
plaincopy
//JNI
//初始化,读取待编码数据的宽和高
public native int initial(int width,int height);
//读取yuv数据进行编码
public native int encode(byte[] yuvimage);
//清空缓存的帧
public native int flush();
//清理
public native int close();
第二步:对应的c文件内容如下,基本就是一个将yuv数据编码为H.264的flv文件的流程,唯一需要注意的就是安卓摄像头拍摄数据的像素格式为NV21,需要转换为YUV420P才能进行编码
[cpp] view
plaincopy
/**
* 基于FFmpeg安卓摄像头编码
* FFmpeg Android Camera Encoder
*
* 张晖 Hui Zhang
* zhanghuicuc@gmail.com
* 中国传媒大学/数字电视技术
* Communication University of China / Digital TV Technology
*
*
*/
#include <stdio.h>
#include <time.h>
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.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
***FormatContext *ofmt_ctx;
***Stream* video_st;
***CodecContext* pCodecCtx;
***Codec* pCodec;
***Packet enc_pkt;
***Frame *pFrameYUV;
int framecnt = 0;
int yuv_width;
int yuv_height;
int y_length;
int uv_length;
int64_t start_time;
//Output FFmpeg's av_log()
void custom_log(void *ptr, int level, const char* fmt, va_list vl){
FILE *fp=fopen("/storage/emulated/0/av_log.txt","a+");
if(fp){
vfprintf(fp,fmt,vl);
fflush(fp);
fclose(fp);
}
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_initial
(JNIEnv *env, jobject obj,jint width,jint height)
{
const char* out_path = "/sdcard/zhanghui/testffmpeg.flv";
yuv_width=width;
yuv_height=height;
y_length=width*height;
uv_length=width*height/4;
//FFmpeg av_log() callback
av_log_set_callback(custom_log);
av_register_all();
//output initialize
avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_path);
//output encoder initialize
pCodec = avcodec_find_encoder(***_CODEC_ID_H264);
if (!pCodec){
LOGE("Can not find encoder!\n");
return -1;
}
pCodecCtx = avcodec_alloc_context3(pCodec);
pCodecCtx->pix_fmt = PIX_FMT_YUV420P;
pCodecCtx->width = width;
pCodecCtx->height = height;
pCodecCtx->time_base.num = 1;
pCodecCtx->time_base.den = 30;
pCodecCtx->bit_rate = 800000;
pCodecCtx->gop_size = 300;
/* Some formats want stream headers to be separate. */
if (ofmt_ctx->oformat->flags & ***FMT_GLOBALHEADER)
pCodecCtx->flags |= CODEC_FLAG_GLOBAL_HEADER;
//H264 codec param
//pCodecCtx->me_range = 16;
//pCodecCtx->max_qdiff = 4;
//pCodecCtx->qcompress = 0.6;
pCodecCtx->qmin = 10;
pCodecCtx->qmax = 51;
//Optional Param
pCodecCtx->max_b_frames = 3;
// Set H264 preset and tune
***Dictionary *param = 0;
av_dict_set(¶m, "preset", "ultrafast", 0);
av_dict_set(¶m, "tune", "zerolatency", 0);
if (avcodec_open2(pCodecCtx, pCodec, ¶m) < 0){
LOGE("Failed to open encoder!\n");
return -1;
}
//Add a new stream to output,should be called by the user before avformat_write_header() for muxing
video_st = avformat_new_stream(ofmt_ctx, pCodec);
if (video_st == NULL){
return -1;
}
video_st->time_base.num = 1;
video_st->time_base.den = 30;
video_st->codec = pCodecCtx;
//Open output URL,set before avformat_write_header() for muxing
if (avio_open(&ofmt_ctx->pb, out_path, ***IO_FLAG_READ_WRITE) < 0){
LOGE("Failed to open output file!\n");
return -1;
}
//Write File Header
avformat_write_header(ofmt_ctx, NULL);
start_time = av_gettime();
return 0;
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_encode
(JNIEnv *env, jobject obj, jbyteArray yuv)
{
int ret;
int enc_got_frame=0;
int i=0;
pFrameYUV = avcodec_alloc_frame();
uint8_t *out_buffer = (uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));
avpicture_fill((***Picture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
//安卓摄像头数据为NV21格式,此处将其转换为YUV420P格式
jbyte* in= (jbyte*)(*env)->GetByteArrayElements(env,yuv,0);
memcpy(pFrameYUV->data[0],in,y_length);
for(i=0;i<uv_length;i++)
{
*(pFrameYUV->data[2]+i)=*(in+y_length+i*2);
*(pFrameYUV->data[1]+i)=*(in+y_length+i*2+1);
}
pFrameYUV->format = ***_PIX_FMT_YUV420P;
pFrameYUV->width = yuv_width;
pFrameYUV->height = yuv_height;
enc_pkt.data = NULL;
enc_pkt.size = 0;
av_init_packet(&enc_pkt);
ret = avcodec_encode_video2(pCodecCtx, &enc_pkt, pFrameYUV, &enc_got_frame);
av_frame_free(&pFrameYUV);
if (enc_got_frame == 1){
LOGI("Succeed to encode frame: %5d\tsize:%5d\n", framecnt, enc_pkt.size);
framecnt++;
enc_pkt.stream_index = video_st->index;
//Write PTS
***Rational time_base = ofmt_ctx->streams[0]->time_base;//{ 1, 1000 };
***Rational r_framerate1 = {60, 2 };//{ 50, 2 };
***Rational time_base_q = { 1, ***_TIME_BASE };
//Duration between 2 frames (us)
int64_t calc_duration = (double)(***_TIME_BASE)*(1 / av_q2d(r_framerate1)); //内部时间戳
//Parameters
//enc_pkt.pts = (double)(framecnt*calc_duration)*(double)(av_q2d(time_base_q)) / (double)(av_q2d(time_base));
enc_pkt.pts = av_rescale_q(framecnt*calc_duration, time_base_q, time_base);
enc_pkt.dts = enc_pkt.pts;
enc_pkt.duration = av_rescale_q(calc_duration, time_base_q, time_base); //(double)(calc_duration)*(double)(av_q2d(time_base_q)) / (double)(av_q2d(time_base));
enc_pkt.pos = -1;
//Delay
int64_t pts_time = av_rescale_q(enc_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);
ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
av_free_packet(&enc_pkt);
}
return 0;
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_flush
(JNIEnv *env, jobject obj)
{
int ret;
int got_frame;
***Packet enc_pkt;
if (!(ofmt_ctx->streams[0]->codec->codec->capabilities &
CODEC_CAP_DELAY))
return 0;
while (1) {
enc_pkt.data = NULL;
enc_pkt.size = 0;
av_init_packet(&enc_pkt);
ret = avcodec_encode_video2(ofmt_ctx->streams[0]->codec, &enc_pkt,
NULL, &got_frame);
if (ret < 0)
break;
if (!got_frame){
ret = 0;
break;
}
LOGI("Flush Encoder: Succeed to encode 1 frame!\tsize:%5d\n", enc_pkt.size);
//Write PTS
***Rational time_base = ofmt_ctx->streams[0]->time_base;//{ 1, 1000 };
***Rational r_framerate1 = { 60, 2 };
***Rational time_base_q = { 1, ***_TIME_BASE };
//Duration between 2 frames (us)
int64_t calc_duration = (double)(***_TIME_BASE)*(1 / av_q2d(r_framerate1)); //内部时间戳
//Parameters
enc_pkt.pts = av_rescale_q(framecnt*calc_duration, time_base_q, time_base);
enc_pkt.dts = enc_pkt.pts;
enc_pkt.duration = av_rescale_q(calc_duration, time_base_q, time_base);
//转换PTS/DTS(Convert PTS/DTS)
enc_pkt.pos = -1;
framecnt++;
ofmt_ctx->duration = enc_pkt.duration * framecnt;
/* mux encoded frame */
ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
if (ret < 0)
break;
}
//Write file trailer
av_write_trailer(ofmt_ctx);
return 0;
}
JNIEXPORT jint JNICALL Java_com_zhanghui_test_MainActivity_close
(JNIEnv *env, jobject obj)
{
if (video_st)
avcodec_close(video_st->codec);
avio_close(ofmt_ctx->pb);
avformat_free_context(ofmt_ctx);
return 0;
}
第三步:编写Android.mk如下,这里要在jni目录下放入ffmpeg的头文件,就跟平时的调用方法一样
[plain] view
plaincopy
LOCAL_PATH := $(call my-dir)
# FFmpeg library
include $(CLEAR_VARS)
LOCAL_MODULE := avcodec
LOCAL_SRC_FILES := libavcodec-56.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avdevice
LOCAL_SRC_FILES := libavdevice-56.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avfilter
LOCAL_SRC_FILES := libavfilter-5.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avformat
LOCAL_SRC_FILES := libavformat-56.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := avutil
LOCAL_SRC_FILES := libavutil-54.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := postproc
LOCAL_SRC_FILES := libpostproc-53.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := swresample
LOCAL_SRC_FILES := libswresample-1.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := swscale
LOCAL_SRC_FILES := libswscale-3.so
include $(PREBUILT_SHARED_LIBRARY)
# Program
include $(CLEAR_VARS)
LOCAL_MODULE := encode
LOCAL_SRC_FILES :=encode.c
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include
LOCAL_LDLIBS := -llog -lz
LOCAL_SHARED_LIBRARIES := avcodec avdevice avfilter avformat avutil postproc swresample swscale
include $(BUILD_SHARED_LIBRARY)
第四步:使用cygwin切换到当前项目的jni目录下,输入ndk-build进行编译即可,如下
此时就可以在当前项目的libs目录下看到ffmpeg所有的类库以及我们自己的类库,我这里是libencode.so,如下
第五步:在java中加载动态库
[java] view
plaincopy
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("encode");
}
至此,就可以在java中调用我们声明的四个方法了。
java部分获取摄像头数据并编码的流程
简单来说,就是利用Camera的PreviewCallback获得摄像头数据,在通过AsyncTask开启后台线程将摄像头数据进行编码。这里为了避免编码过程占用过多的硬件资源,将编码视频宽和高设置为了640和480,。这里有两个坑,一是onPreviewFrame方法的arg0参数就是YUV数据了,不要再转换为YuvImage对象了,否则会在头部加上一些多余的信息,导致编码错误,二是用于清空缓存帧的flush方法不能在oncreate主线程中调用,否则会导致程序闪退,目前还不清楚原因,所以这里连同close()方法一起放到了onPause方法中进行调用,在安卓开发方面我还是新手,希望有了解这个问题怎么解决的朋友多多指教。
[java] view
plaincopy
package com.zhanghui.test;
import java.io.IOException;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
@SuppressWarnings("deprecation")
public class MainActivity extends Activity {
private static final String TAG= "MainActivity";
private Button mTakeButton;
private Camera mCamera;
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private boolean isRecording = false;
private class StreamTask extends AsyncTask<Void, Void, Void>{
private byte[] mData;
//构造函数
StreamTask(byte[] data){
this.mData = data;
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
if(mData!=null){
Log.i(TAG, "fps: " + mCamera.getParameters().getPreviewFrameRate());
encode(mData);
}
return null;
}
}
private StreamTask mStreamTask;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Camera.PreviewCallback mPreviewCallbacx=new Camera.PreviewCallback() {
@Override
public void onPreviewFrame(byte[] arg0, Camera arg1) {
// TODO Auto-generated method stub
if(null != mStreamTask){
switch(mStreamTask.getStatus()){
case RUNNING:
return;
case PENDING:
mStreamTask.cancel(false);
break;
}
}
mStreamTask = new StreamTask(arg0);
mStreamTask.execute((Void)null);
}
};
mTakeButton=(Button)findViewById(R.id.take_button);
PackageManager pm=this.getPackageManager();
boolean hasCamera=pm.hasSystemFeature(PackageManager.FEATURE_CAMERA) ||
pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT) ||
Build.VERSION.SDK_INT<Build.VERSION_CODES.GINGERBREAD;
if(!hasCamera)
mTakeButton.setEnabled(false);
mTakeButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if(mCamera!=null)
{
if (isRecording) {
mTakeButton.setText("Start");
mCamera.setPreviewCallback(null);
Toast.makeText(MainActivity.this, "encode done", Toast.LENGTH_SHORT).show();
isRecording = false;
}else {
mTakeButton.setText("Stop");
initial(mCamera.getParameters().getPreviewSize().width,mCamera.getParameters().getPreviewSize().height);
mCamera.setPreviewCallback(mPreviewCallbacx);
isRecording = true;
}
}
}
});
mSurfaceView=(SurfaceView)findViewById(R.id.surfaceView1);
SurfaceHolder holder=mSurfaceView.getHolder();
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
holder.addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
if(mCamera!=null)
{
mCamera.stopPreview();
mSurfaceView = null;
mSurfaceHolder = null;
}
}
@Override
public void surfaceCreated(SurfaceHolder arg0) {
// TODO Auto-generated method stub
try{
if(mCamera!=null){
mCamera.setPreviewDisplay(arg0);
mSurfaceHolder=arg0;
}
}catch(IOException exception){
Log.e(TAG, "Error setting up preview display", exception);
}
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
if(mCamera==null) return;
Camera.Parameters parameters=mCamera.getParameters();
parameters.setPreviewSize(640,480);
parameters.setPictureSize(640,480);
mCamera.setParameters(parameters);
try{
mCamera.startPreview();
mSurfaceHolder=arg0;
}catch(Exception e){
Log.e(TAG, "could not start preview", e);
mCamera.release();
mCamera=null;
}
}
});
}
@TargetApi(9)
@Override
protected void onResume(){
super.onResume();
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.GINGERBREAD){
mCamera=Camera.open(0);
}else
{
mCamera=Camera.open();
}
}
@Override
protected void onPause(){
super.onPause();
flush();
close();
if(mCamera!=null){
mCamera.release();
mCamera=null;
}
}
@Override
public 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;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
//JNI
public native int initial(int width,int height);
public native int encode(byte[] yuvimage);
public native int flush();
public native int close();
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("encode");
}
}
至此,就完成了全部功能的开发,程序截图如下
首先由用户按下take键开始摄像
此时按键转为stop,按下即可停止摄像
按下stop后,即停止摄像,弹出encode done信息,退出程序即可在对应目录下看到编码的flv视频
项目源代码下载地址
github地址
https://github.com/zhanghuicuc/FFmpegAndroidCameraEncoder
来自:http://blog.csdn.net/nonmarking/article/details/48601317
相关文章推荐
- Android中Application类用法
- STM32之GPIO配置问题
- OpenGL ES学习笔记(一)——基本用法、绘制流程与着色器编译
- (一)NOR FALSH 讲解
- mycat server.xml的优化
- ZABBIX封装HTML说明
- [CSS3] Animation
- 修改ssh服务的默认端口
- SQL0575N db2查询视图报错
- bootstrap 水平排列表单
- mysql: Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '= 的解决
- 修改ssh服务的默认端口
- phpExcel导出大量数据出现内存溢出错误的解决方法
- 支付开发
- 如何使用 Cloud Insight SDK 实现 Druid 监控?
- 用svn上的文件,覆盖本地文件
- QML之SpinBox使用
- MySQL 列变行 数据变换 行列转换
- servlet容器浅析
- CVI生成发布包的问题