FFmpeg在Android使用3
android 移植ffmpeg后so库的使用
只需要将我们编译好的ffmpeg的so包(在/obj/local/armeabi/libffmpeg.so)copy到所在ndk下的\platforms\android-8\arch-arm\usr\lib文件夹下就可以了。
再看下我们的代码吧:
- public class HelloJni extends Activity
- {
- /** Called when the activity is first created. */
- @Override
- public void onCreate(Bundle savedInstanceState)
- {
- super.onCreate(savedInstanceState);
- /* Create a TextView and set its content.
- * the text is retrieved by calling a native
- * function.
- */
- TextView tv = new TextView(this);
- String str = String.valueOf(stringFromJNI());
- str = str +"\n"+getVoice();
- tv.setText(str);
- setContentView(tv);
- }
- public native int getVoice();
- public native String stringFromJNI();
- public native String unimplementedStringFromJNI();
- static {
- System.loadLibrary("ffmpeg");
- System.loadLibrary("hello-jni");
- }
- }
- /*
- * Copyright (C) 2009 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
- #include <string.h>
- #include <jni.h>
- #include <android/log.h>
- #include <ffmpeg/libavcodec/avcodec.h>
- #include <ffmpeg/libavformat/avformat.h>
- #include <ffmpeg/libswscale/swscale.h>
- #include <string.h>
- #define LOG_TAG "***************************lixingyun*****************" // 这个是自定义的LOG的标识
- #undef LOG // 取消默认的LOG
- #define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG,LOG_TAG,__VA_ARGS__) // 定义LOG类型
- #define LOGI(...) __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__) // 定义LOG类型
- #define LOGW(...) __android_log_print(ANDROID_LOG_WARN,LOG_TAG,__VA_ARGS__) // 定义LOG类型
- #define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS__) // 定义LOG类型
- #define LOGF(...) __android_log_print(ANDROID_LOG_FATAL,LOG_TAG,__VA_ARGS__) // 定义LOG类型
- /* This is a trivial JNI example where we use a native method
- * to return a new VM String. See the corresponding Java source
- * file located at:
- *
- * apps/samples/hello-jni/project/src/com/example/HelloJni/HelloJni.java
- */
- JNIEXPORT jstring Java_com_example_hellojni_HelloJni_stringFromJNI(JNIEnv* env,
- jobject thiz) {
- char str[25];
- sprintf(str, "%d", avcodec_version());
- return (*env)->NewStringUTF(env, str);
- // return (*env)->NewStringUTF(env, "Hello from JNI !");0
- }
- JNIEXPORT jint Java_com_example_hellojni_HelloJni_getVoice(JNIEnv* env,
- jobject thiz) {
- int flag = 0;
- AVPacket aacpkt;
- aacpkt.data = NULL;
- aacpkt.size = 0;
- const char *filename = "file:/sdcard/test.mp3";
- av_init_packet(&aacpkt);
- av_register_all(); //注册所有可解码类型
- AVFormatContext *pInFmtCtx = NULL; //文件格式
- AVCodecContext *pInCodecCtx = NULL; //编码格式
- pInFmtCtx = avformat_alloc_context();
- if (av_open_input_file(&pInFmtCtx, filename, NULL, 0, NULL) != 0) //获取文件格式
- LOGE("av_open_input_file error\n");
- if (av_find_stream_info(pInFmtCtx) < 0) //获取文件内音视频流的信息
- LOGE("av_find_stream_info error\n");
- unsigned int j;
- // Find the first audio stream
- int audioStream = -1;
- // Dump information about file onto standard error
- dump_format(pInFmtCtx, 0, filename, 0);
- //从FormatdContext的中找到对应流对应的编码类型,若是CODEC_TYPE_AUDIO则表示是音频
- for (j = 0; j < pInFmtCtx->nb_streams; j++) //找到音频对应的stream
- if (pInFmtCtx->streams[j]->codec->codec_type == CODEC_TYPE_AUDIO) {
- audioStream = j;
- break;
- }
- if (audioStream == -1) {
- printf("input file has no audio stream\n");
- return 0; // Didn't find a audio stream
- }
- LOGE("audio stream num: %d\n", audioStream);
- pInCodecCtx = pInFmtCtx->streams[audioStream]->codec; //音频的编码上下文
- AVCodec *pInCodec = NULL;
- /* FILE *file3 = fopen("codec_private_data_size.txt","w");
- for(int i = 0; i <200000; i++)
- {
- pInCodec = avcodec_find_decoder((CodecID)i);
- if (pInCodec!=NULL)
- {
- fprintf(file3,"%s %d\n",pInCodec->name,pInCodec->priv_data_size );
- }
- }
- fclose(file3);
- system("pause");
- */
- pInCodec = avcodec_find_decoder(pInCodecCtx->codec_id); //根据编码ID找到用于解码的结构体
- if (pInCodec == NULL) {
- printf("error no Codec found\n");
- return -1; // Codec not found
- }
- //使用test的代替pInCodecCtx也可以完成解码,可以看出只要获取以下几个重要信息就可以实现解码和重采样
- AVCodecContext *test = avcodec_alloc_context();
- test->bit_rate = pInCodecCtx->bit_rate; //重采样用
- test->sample_rate = pInCodecCtx->sample_rate; //重采样用
- test->channels = pInCodecCtx->channels; //重采样用
- test->extradata = pInCodecCtx->extradata; //若有则必有
- test->extradata_size = pInCodecCtx->extradata_size; //若有则必要
- test->codec_type = CODEC_TYPE_AUDIO; //不必要
- test->block_align = pInCodecCtx->block_align; //必要
- if (avcodec_open(test, pInCodec) < 0) //将两者结合以便在下面的解码函数中调用pInCodec中的对应解码函数
- {
- printf("error avcodec_open failed.\n");
- return -1; // Could not open codec
- }
- if (avcodec_open(pInCodecCtx, pInCodec) < 0) {
- printf("error avcodec_open failed.\n");
- return -1; // Could not open codec
- }
- static AVPacket packet;
- LOGI(" bit_rate = %d \r\n", pInCodecCtx->bit_rate);
- LOGI(" sample_rate = %d \r\n", pInCodecCtx->sample_rate);
- LOGI(" channels = %d \r\n", pInCodecCtx->channels);
- LOGI(" code_name = %s \r\n", pInCodecCtx->codec->name);
- //LOGI("extra data size: %d :data%x %x %x %x\n",pInCodecCtx->extradata_size,pInCodecCtx->extradata[0]
- // ,pInCodecCtx->extradata[1],pInCodecCtx->extradata[2],pInCodecCtx->extradata[3]);
- LOGI(" block_align = %d\n", pInCodecCtx->block_align);
- /********************************************************/
- unsigned char *outbuf = NULL;
- outbuf = (unsigned char *) malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE * 2);
- int outsize;
- outsize = AVCODEC_MAX_AUDIO_FRAME_SIZE * 2;
- int len = 0;
- int size = 0;
- FILE *out_fp;
- out_fp = fopen("out.dat", "wb+");
- while (av_read_frame(pInFmtCtx, &aacpkt) >= 0) {
- LOGI("***************************");
- if (aacpkt.stream_index == audioStream) {
- int declen = 0;
- size = aacpkt.size;
- while (aacpkt.size > 0) {
- outsize = AVCODEC_MAX_AUDIO_FRAME_SIZE * 2;
- memset(outbuf, 0, outsize);
- len = avcodec_decode_audio3(pInCodecCtx, (int16_t *) outbuf,
- &outsize, &aacpkt);
- if (len < 0) {
- printf("avcodec_decode_audio3 failed!\n");
- break;
- }
- if (outsize > 0) {
- fwrite(outbuf, 1, outsize, out_fp);
- printf("write %d bytes\n", outsize);
- }
- declen += len;
- if (declen == size) {
- av_free_packet(&aacpkt);
- printf("packet decoded succeed!\n");
- break;
- } else if (declen < size) {
- aacpkt.size -= len;
- aacpkt.data += len;
- } else {
- printf("decode error!\n");
- break;
- }
- }
- }
- }
- fclose(out_fp);
- // Close the codec
- avcodec_close(pInCodecCtx);
- // Close the video file
- av_close_input_file(pInFmtCtx);
- return flag;
- }
其中的LOGE那几个就是Android下的哦。
再附上Android.mk的东西吧:
- LOCAL_PATH := $(call my-dir)
- include $(CLEAR_VARS)
- PATH_TO_FFMPEG_SOURCE:=$(LOCAL_PATH)/ffmpeg
- LOCAL_C_INCLUDES += $(PATH_TO_FFMPEG_SOURCE)
- LOCAL_LDLIBS := -lffmpeg -llog
- LOCAL_MODULE := hello-jni
- LOCAL_SRC_FILES := hello-jni.c
- include $(BUILD_SHARED_LIBRARY)
哈哈,这样就Ok了。
源码也附上吧.
失败是什么?没有什么,只是更走近成功一步;成功是什么?就是走过了所有通向失败的路,只剩下一条路,那就是成功的路。