(一）.目的：在Android Studio上呼叫FFmpeg,播放視頻，rtsp流
（二）.準備作業：ffmpeg庫下載 ndk下載 （我用的是 android-ndk-r20b Ffmpeg 3.0)
（三）.1.環境變數中配置好ndk路徑 ，如下圖：
2.Android Studio中配置好ndk路徑，如下圖：
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（四）.呼叫FFmpeg的整體呼叫邏輯為：
1 編譯完ffmpeg庫（我直接網上拷貝下來編譯好的）
2 使用jni方式撰寫c代碼，其中需要包含相應的ffmpeg的頭檔案
3 撰寫相應的Android.mk檔案，里面指定需要編譯的c代碼以及需要鏈接的動態庫
4 執行ndk-build生成相應的jni庫
5 創建andorid java程式，代碼中loadLibrary相應ffmpeg庫以及剛才生成的jni庫
6 靜態方法宣告native函式，這些函式在jni寫的c語言中都已經實作過
我的操作順序和上面的排序有些不一樣，但是每一步都是不能缺少的，我只是順序不同而已，最終不影響運行
1.操作如下：在main下新建jni檔案夾
2.加入編譯好的庫和自定義的方法（我自己創建了一個類MyNdk）
注意點：play是視頻播放的方法，別的方法可以不要，對應的test.c里面也只留play的方法
3.生成com_example_im_myapplication_MyNdk.h 檔案
javah -encoding UTF-8 -classpath C:\Users\IM\AppData\Local\Android\Sdk\platforms\android-25\android.jar;. -jni com.example.im.ffmpegtest3.MainActivity（自己專案的路徑）
4.在Jni 包下面加入已經編譯好的 ffmpeg庫中的Inclued 和 lib 檔案夾，直接復制進來
5.加入 Android.mk Application.mk test.c
a:Android.mk 檔案代碼如下：
LOCAL_PATH := $(call my-dir) # FFmpeg library include $(CLEAR_VARS) LOCAL_MODULE := avcodec LOCAL_SRC_FILES := libavcodec-57.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := avfilter LOCAL_SRC_FILES := libavfilter-6.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := avformat LOCAL_SRC_FILES := libavformat-57.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := avutil LOCAL_SRC_FILES := libavutil-55.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := swresample LOCAL_SRC_FILES := libswresample-2.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := swscale LOCAL_SRC_FILES := libswscale-4.so include $(PREBUILT_SHARED_LIBRARY) # Program include $(CLEAR_VARS) LOCAL_MODULE := MyApplication（名字要對應） LOCAL_SRC_FILES := test.c （名字要對應） LOCAL_C_INCLUDES += $(LOCAL_PATH)/include LOCAL_LDLIBS := -llog -lz -landroid LOCAL_SHARED_LIBRARIES := avcodec avfilter avformat avutil swresample swscale include $(BUILD_SHARED_LIBRARY)
b: Application.mk代碼如下：
APP_ABI := armeabi-v7a APP_MODULES := MyApplication（名字要對應）
c:test.c代碼如下：方法的名字格式要注意一下，最容易出錯了
#include <stdio.h>
#include "com_example_im_myapplication_MyNdk.h"
#include "include/libavformat/avformat.h"
#include "include/libavcodec/avcodec.h"
#include "include/libavutil/avutil.h"
#include "include/libavfilter/avfilter.h"
#include <android/native_window_jni.h>
#include <android/native_window.h>
#include <jni.h>
#include <android/log.h>
#define LOG_TAG "JNI"
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
#define SWS_BICUBIC 4
#define SWS_BILINEAR 2
/**
* com.ihubin.ffmpegstudy.MainActivity.avformatinfo()
* AVFormat Support Information
*/
JNIEXPORT jstring Java_com_example_im_myapplication_MyNdk_avformatinfo(JNIEnv *env, jobject obj){
char info[40000] = { 0 };
av_register_all();
AVInputFormat *if_temp = av_iformat_next(NULL);
AVOutputFormat *of_temp = av_oformat_next(NULL);
//Input
while(if_temp!=NULL){
sprintf(info, "%s[In ][%10s]\n", info, if_temp->name);
if_temp=if_temp->next;
}
//Output
while (of_temp != NULL){
sprintf(info, "%s[Out][%10s]\n", info, of_temp->name);
of_temp = of_temp->next;
}
//LOGE("%s", info);
return (*env)->NewStringUTF(env, info);
}
/**
* com.ihubin.ffmpegstudy.MainActivity.avcodecinfo()
* AVCodec Support Information
*/
JNIEXPORT jstring JNICALL Java_com_example_im_myapplication_MyNdk_avcodecinfo(JNIEnv *env, jobject obj)
{
char info[40000] = { 0 };
av_register_all();
AVCodec *c_temp = av_codec_next(NULL);
while(c_temp!=NULL){
if (c_temp->decode!=NULL){
sprintf(info, "%s[Dec]", info);
}
else{
sprintf(info, "%s[Enc]", info);
}
switch (c_temp->type){
case AVMEDIA_TYPE_VIDEO:
sprintf(info, "%s[Video]", info);
break;
case AVMEDIA_TYPE_AUDIO:
sprintf(info, "%s[Audio]", info);
break;
default:
sprintf(info, "%s[Other]", info);
break;
}
sprintf(info, "%s[%10s]\n", info, c_temp->name);
c_temp=c_temp->next;
}
//LOGE("%s", info);
return (*env)->NewStringUTF(env, info);
}
/**
* com.ihubin.ffmpegstudy.MainActivity.avfilterinfo()
* AVFilter Support Information
*/
JNIEXPORT jstring JNICALL Java_com_example_im_myapplication_MyNdk_avfilterinfo(JNIEnv *env, jobject obj)
{
char info[40000] = { 0 };
avfilter_register_all();
AVFilter *f_temp = (AVFilter *)avfilter_next(NULL);
int i = 0;
while (f_temp != NULL){
sprintf(info, "%s[%10s]\n", info, f_temp->name);
f_temp = f_temp->next;
}
return (*env)->NewStringUTF(env, info);
}
/**
* com.ihubin.ffmpegstudy.MainActivity.urlprotocolinfo()
* Protocol Support Information
*/
JNIEXPORT jstring JNICALL Java_com_example_im_ffmpegtest3_MainActivity_configurationinfo(JNIEnv *env, jobject obj)
{
char info[10000] = {0};
av_register_all();
sprintf(info, "%s\n", avcodec_configuration());
//LOGE("%s", info);
return (*env)->NewStringUTF(env, info);
}
//2020-12-24wpp
static AVPacket *vPacket;
static AVFrame *vFrame, *pFrameRGBA;
static AVCodecContext *vCodecCtx;
struct SwsContext *img_convert_ctx;
static AVFormatContext *pFormatCtx;
ANativeWindow* nativeWindow;
ANativeWindow_Buffer windowBuffer;
uint8_t *v_out_buffer;
JNIEXPORT void JNICALL Java_com_example_im_myapplication_MyNdk_play(JNIEnv *env, jclass clazz, jstring url, jobject surface) {
//char input_str[500]={0};
//sprintf(input_str, "%s", (*env)->GetStringUTFChars(env,url,NULL));
// LOGI("%s",input_str);
char file_name[500]={0};
//讀取輸入的視頻頻檔案地址
sprintf(file_name, "%s", (*env)->GetStringUTFChars(env,url, NULL));
//LOGI("%s",file_name);
// char * file_name = "/storage/emulated/999/tencent/MicroMsg/WeiXin/mmexport1588601045658.mp4";
av_register_all();
AVFormatContext * pFormatCtx = avformat_alloc_context();
//AVDictionary* options = NULL;
//av_dict_set(&options, "rtsp_transport", "udp", 0);
// Open video file
if(avformat_open_input(&pFormatCtx, file_name, NULL, NULL)!=0) {
LOGE("Couldn't open file:%s\n", file_name);
return; // Couldn't open file
}
// Retrieve stream information
if(avformat_find_stream_info(pFormatCtx, NULL)<0) {
LOGE("Couldn't find stream information.");
return;
}
// Find the first video stream
int videoStream = -1,i;
for (i = 0; i < pFormatCtx->nb_streams; i++) {
if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO
&& videoStream < 0) {
videoStream = i;
}
}
if(videoStream==-1) {
LOGE("Didn't find a video stream.");
return; // Didn't find a video stream
}
// Get a pointer to the codec context for the video stream
AVCodecContext * pCodecCtx = pFormatCtx->streams[videoStream]->codec;
// Find the decoder for the video stream
AVCodec * pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
if(pCodec==NULL) {
LOGE("Codec not found.");
return; // Codec not found
}
if(avcodec_open2(pCodecCtx, pCodec, NULL) < 0) {
LOGE("Could not open codec.");
return; // Could not open codec
}
// 獲取native window
ANativeWindow* nativeWindow = ANativeWindow_fromSurface(env, surface);
// 獲取視頻寬高
int videoWidth = pCodecCtx->width;
int videoHeight = pCodecCtx->height;
// 設定native window的buffer大小,可自動拉伸
ANativeWindow_setBuffersGeometry(nativeWindow, videoWidth, videoHeight, WINDOW_FORMAT_RGBA_8888);
ANativeWindow_Buffer windowBuffer;
if(avcodec_open2(pCodecCtx, pCodec, NULL)<0) {
LOGE("Could not open codec.");
return; // Could not open codec
}
// Allocate video frame
AVFrame * pFrame = av_frame_alloc();
// 用于渲染
AVFrame * pFrameRGBA = av_frame_alloc();
if(pFrameRGBA == NULL || pFrame == NULL) {
LOGE("Could not allocate video frame.");
return;
}
// Determine required buffer size and allocate buffer
int numBytes=av_image_get_buffer_size(AV_PIX_FMT_RGBA, pCodecCtx->width, pCodecCtx->height, 1);
uint8_t * buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
av_image_fill_arrays(pFrameRGBA->data, pFrameRGBA->linesize, buffer, AV_PIX_FMT_RGBA,
pCodecCtx->width, pCodecCtx->height, 1);
// 由于解碼出來的幀格式不是RGBA的,在渲染之前需要進行格式轉換
struct SwsContext *sws_ctx = sws_getContext(pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
pCodecCtx->width,
pCodecCtx->height,
AV_PIX_FMT_RGBA,
SWS_BILINEAR,
NULL,
NULL,
NULL);
int frameFinished;
AVPacket packet;
while(av_read_frame(pFormatCtx, &packet)>=0) {
// Is this a packet from the video stream?
if(packet.stream_index==videoStream) {
// Decode video frame
avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
// 并不是decode一次就可解碼出一幀
if (frameFinished) {
// lock native window buffer
ANativeWindow_lock(nativeWindow, &windowBuffer, 0);
// 格式轉換
sws_scale(sws_ctx, (uint8_t const * const *)pFrame->data,
pFrame->linesize, 0, pCodecCtx->height,
pFrameRGBA->data, pFrameRGBA->linesize);
// 獲取stride
uint8_t * dst = windowBuffer.bits;
int dstStride = windowBuffer.stride * 4;
uint8_t * src = (uint8_t*) (pFrameRGBA->data[0]);
int srcStride = pFrameRGBA->linesize[0];
// 由于window的stride和幀的stride不同,因此需要逐行復制
int h;
// LOGI("%d",videoHeight);
for (h = 0; h < videoHeight; h++) {
memcpy(dst + h * dstStride, src + h * srcStride, srcStride);
}
//LOGI("%s","111111111111");
ANativeWindow_unlockAndPost(nativeWindow);
}
}
av_packet_unref(&packet);
}
//記憶體釋放
ANativeWindow_release(nativeWindow);
av_free(buffer);
av_free(pFrameRGBA);
// Free the YUV frame
av_free(pFrame);
// Close the codecs
avcodec_close(pCodecCtx);
// Close the video file
avformat_close_input(&pFormatCtx);
//return 0;
}
注意點：①include 檔案名稱別寫錯了 ② 方法的名字格式不要錯了 ③Java_com_example_im_myapplication_MyNdk_play是視頻播放的方法，別的方法可以不要
6.ndk-build，先進入到jni的目錄下
有時候會提示不存在該命令：那么先set path一下 set path=D:\software\android-ndk-r20b\build 然后再ndk-buil（根據自己的地址來）
6.現在只要在界面上顯示出來就可以了
7.運行成功：
研究了好久，終于研究出來了，開心，為自己鼓個掌
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標籤：其他