工业安卓怎么解码
① 如何在Android用FFmpeg解码图像
创建一个VideoPicture结构体用来保存解码出来的图像。
LOCAL_PATH := $(call my-dir)
###########################
#
# SDL shared library
#
###########################
include $(CLEAR_VARS)
LOCAL_MODULE := SDL2
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
LOCAL_SRC_FILES := \
$(subst $(LOCAL_PATH)/,, \
$(wildcard $(LOCAL_PATH)/src/*.c) \
$(wildcard $(LOCAL_PATH)/src/audio/*.c) \
$(wildcard $(LOCAL_PATH)/src/audio/android/*.c) \
$(wildcard $(LOCAL_PATH)/src/audio/mmy/*.c) \
$(LOCAL_PATH)/src/atomic/SDL_atomic.c \
$(LOCAL_PATH)/src/atomic/SDL_spinlock.c.arm \
$(wildcard $(LOCAL_PATH)/src/core/android/*.c) \
$(wildcard $(LOCAL_PATH)/src/cpuinfo/*.c) \
$(wildcard $(LOCAL_PATH)/src/dynapi/*.c) \
$(wildcard $(LOCAL_PATH)/src/events/*.c) \
$(wildcard $(LOCAL_PATH)/src/file/*.c) \
$(wildcard $(LOCAL_PATH)/src/haptic/*.c) \
$(wildcard $(LOCAL_PATH)/src/haptic/mmy/*.c) \
$(wildcard $(LOCAL_PATH)/src/joystick/*.c) \
$(wildcard $(LOCAL_PATH)/src/joystick/android/*.c) \
$(wildcard $(LOCAL_PATH)/src/loadso/dlopen/*.c) \
$(wildcard $(LOCAL_PATH)/src/power/*.c) \
$(wildcard $(LOCAL_PATH)/src/power/android/*.c) \
$(wildcard $(LOCAL_PATH)/src/filesystem/mmy/*.c) \
$(wildcard $(LOCAL_PATH)/src/render/*.c) \
$(wildcard $(LOCAL_PATH)/src/render/*/*.c) \
$(wildcard $(LOCAL_PATH)/src/stdlib/*.c) \
$(wildcard $(LOCAL_PATH)/src/thread/*.c) \
$(wildcard $(LOCAL_PATH)/src/thread/pthread/*.c) \
$(wildcard $(LOCAL_PATH)/src/timer/*.c) \
$(wildcard $(LOCAL_PATH)/src/timer/unix/*.c) \
$(wildcard $(LOCAL_PATH)/src/video/*.c) \
$(wildcard $(LOCAL_PATH)/src/video/android/*.c) \
$(wildcard $(LOCAL_PATH)/src/test/*.c))
LOCAL_CFLAGS += -DGL_GLEXT_PROTOTYPES
LOCAL_LDLIBS := -ldl -lGLESv1_CM -lGLESv2 -llog -landroid
include $(BUILD_SHARED_LIBRARY)
###########################
#
# SDL static library
#
###########################
#LOCAL_MODULE := SDL2_static
#LOCAL_MODULE_FILENAME := libSDL2
#LOCAL_SRC_FILES += $(LOCAL_PATH)/src/main/android/SDL_android_main.c
#LOCAL_LDLIBS :=
#LOCAL_EXPORT_LDLIBS := -Wl,--undefined=java_org_libsdl_app_SDLActivity_nativeInit -ldl -lGLESv1_CM -lGLESv2 -llog -landroid
#include $(BUILD_STATIC_LIBRARY)
二、参考[原]如何在Android用FFmpeg解码图像， 在工程中新建一个ffmpeg文件夹，将与ffmpeg相关的头文件include进来。ffmpeg文件夹下的Android.mk内容：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg
LOCAL_SRC_FILES := /path/to/build/ffmpeg/libffmpeg.so
include $(PREBUILT_SHARED_LIBRARY)
三、新建player文件夹，用来编写解码与显示文件。player.c文件内容：
/*
* SDL_Lesson.c
*
* Created on: Aug 12, 2014
* Author: clarck
*/
#include <jni.h>
#include <android/native_window_jni.h>
#include "SDL.h"
#include "SDL_thread.h"
#include "SDL_events.h"
#include "../include/logger.h"
#include "../ffmpeg/include/libavcodec/avcodec.h"
#include "../ffmpeg/include/libavformat/avformat.h"
#include "../ffmpeg/include/libavutil/pixfmt.h"
#include "../ffmpeg/include/libswscale/swscale.h"
int main(int argc, char *argv[]) {
char *file_path = argv[1];
LOGI("file_path:%s", file_path);
AVFormatContext *pFormatCtx;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame, *pFrameYUV;
AVPacket *packet;
uint8_t *out_buffer;
SDL_Texture *bmp = NULL;
SDL_Window *screen = NULL;
SDL_Rect rect;
SDL_Event event;
static struct SwsContext *img_convert_ctx;
int videoStream, i, numBytes;
int ret, got_picture;
av_register_all();
pFormatCtx = avformat_alloc_context();
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
LOGE("Could not initialize SDL - %s. \n", SDL_GetError());
exit(1);
}
if (avformat_open_input(&pFormatCtx, file_path, NULL, NULL) != 0) {
LOGE("can't open the file. \n");
return -1;
}
if (avformat_find_stream_info(pFormatCtx, NULL) < 0) {
LOGE("Could't find stream infomation.\n");
return -1;
}
videoStream = 1;
for (i = 0; i < pFormatCtx->nb_streams; i++) {
if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
videoStream = i;
}
}
LOGI("videoStream:%d", videoStream);
if (videoStream == -1) {
LOGE("Didn't find a video stream.\n");
return -1;
}
pCodecCtx = pFormatCtx->streams[videoStream]->codec;
pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
if (pCodec == NULL) {
LOGE("Codec not found.\n");
return -1;
}
if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) {
LOGE("Could not open codec.\n");
return -1;
}
pFrame = av_frame_alloc();
pFrameYUV = av_frame_alloc();
//---------------------------init sdl---------------------------//
screen = SDL_CreateWindow("My Player Window", SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED, pCodecCtx->width, pCodecCtx->height,
SDL_WINDOW_FULLSCREEN | SDL_WINDOW_OPENGL);
SDL_Renderer *renderer = SDL_CreateRenderer(screen, -1, 0);
bmp = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_YV12,
SDL_TEXTUREACCESS_STREAMING, pCodecCtx->width, pCodecCtx->height);
//-------------------------------------------------------------//
img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,
pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,
AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
numBytes = avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx->width,
pCodecCtx->height);
out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
avpicture_fill((AVPicture *) pFrameYUV, out_buffer, AV_PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
rect.x = 0;
rect.y = 0;
rect.w = pCodecCtx->width;
rect.h = pCodecCtx->height;
int y_size = pCodecCtx->width * pCodecCtx->height;
packet = (AVPacket *) malloc(sizeof(AVPacket));
av_new_packet(packet, y_size);
av_mp_format(pFormatCtx, 0, file_path, 0);
while (av_read_frame(pFormatCtx, packet) >= 0) {
if (packet->stream_index == videoStream) {
ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture,
packet);
if (ret < 0) {
LOGE("decode error.\n");
return -1;
}
LOGI("got_picture:%d", got_picture);
if (got_picture) {
sws_scale(img_convert_ctx,
(uint8_t const * const *) pFrame->data,
pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data,
pFrameYUV->linesize);
////iPitch 计算yuv一行数据占的字节数
SDL_UpdateTexture(bmp, &rect, pFrameYUV->data[0], pFrameYUV->linesize[0]);
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer, bmp, &rect, &rect);
SDL_RenderPresent(renderer);
}
SDL_Delay(50);
}
av_free_packet(packet);
SDL_PollEvent(&event);
switch (event.type) {
case SDL_QUIT:
SDL_Quit();
exit(0);
break;
default:
break;
}
② 如何在Android用FFmpeg解码图像
这涉及到两个问题，一个是解码，另一个是显示，解码问题要先交叉编译ffmpeg，然后参考下面的解码流程
avcodec_register_all();
/*
########################################
[1]
########################################
*/
av_register_all();
/*
// Open video file
########################################
[2]
########################################
*/
pFormatCtx = avformat_alloc_context();
if(avformat_open_input(&pFormatCtx, filename, NULL, NULL)!=0)
return -1; // Couldn't open file
// Retrieve stream information
/*
########################################
[3]
########################################
*/
if(avformat_find_stream_info(pFormatCtx,NULL)<0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
// mp_format(pFormatCtx, 0, argv[1], 0);
// Find the first video stream
videoStream=-1;
for(i=0; i<pFormatCtx->nb_streams; i++)
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO) {
videoStream=i;
break;
}
if(videoStream==-1)
return -1; // Didn't find a video stream
// Get a pointer to the codec context for the video stream
pCodecCtx=pFormatCtx->streams[videoStream]->codec;
// Find the decoder for the video stream
pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
if(pCodec==NULL) {
fprintf(stderr, "Unsupported codec!\n");
return -1; // Codec not found
}
// Open codec
if(avcodec_open2(pCodecCtx, pCodec,NULL)<0)
pFrame=avcodec_alloc_frame();
// Allocate an picture structure
avpicture_alloc(&picture, PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height);
// Determine required buffer size and allocate buffer
img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL);
if(img_convert_ctx == NULL)
{
fprintf(stderr, "Cannot initialize the conversion context!\n");
exit(1);
}
// Read frames and save first five frames to disk
/*
########################################
[4]
########################################
*/
i=0;
dirtyRegion.set(android::Rect(0x3FFF, 0x3FFF));
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);
// Did we get a video frame?
if(frameFinished) {
// Convert the image from its native format to RGB
sws_scale(img_convert_ctx,
pFrame->data, pFrame->linesize, 0, pCodecCtx->height,
picture.data, picture.linesize);
}
}
// Free the packet that was allocated by av_read_frame
av_free_packet(&packet);
}
pFrame为解码后的数据，将它显示在画布上，就完成了FFMEPG解码
③ 如何在Android用FFmpeg解码图像
CC libavcodec/log2_tab.o
CC libavutil/log2_tab.o
CC libswresample/log2_tab.o
AR libavcodec/libavcodec.a
LD libavutil/libavutil.so.52
AR libavutil/libavutil.a
AR libswresample/libswresample.a
LD libavcodec/libavcodec.so.55
LD libswresample/libswresample.so.0
LD libswscale/libswscale.so.2
LD libavformat/libavformat.so.55
INSTALL libavformat/libavformat.a
INSTALL libavformat/libavformat.so
STRIP install-libavformat-shared
INSTALL libavcodec/libavcodec.a
INSTALL libavcodec/libavcodec.so
STRIP install-libavcodec-shared
INSTALL libswresample/libswresample.a
INSTALL libswresample/libswresample.so
STRIP install-libswresample-shared
INSTALL libswscale/libswscale.a
INSTALL libswscale/libswscale.so
STRIP install-libswscale-shared
INSTALL libavutil/libavutil.a
INSTALL libavutil/libavutil.so
STRIP install-libavutil-shared
INSTALL libavformat/avformat.h
INSTALL libavformat/avio.h
INSTALL libavformat/version.h
INSTALL libavformat/libavformat.pc
INSTALL libavcodec/avcodec.h
INSTALL libavcodec/avfft.h
INSTALL libavcodec/dxva2.h
INSTALL libavcodec/old_codec_ids.h
INSTALL libavcodec/vaapi.h
INSTALL libavcodec/vda.h
INSTALL libavcodec/vdpau.h
INSTALL libavcodec/version.h
INSTALL libavcodec/xvmc.h
INSTALL libavcodec/libavcodec.pc
INSTALL libswresample/swresample.h
INSTALL libswresample/version.h
INSTALL libswresample/libswresample.pc
INSTALL libswscale/swscale.h
INSTALL libswscale/version.h
INSTALL libswscale/libswscale.pc
INSTALL libavutil/adler32.h
INSTALL libavutil/aes.h
INSTALL libavutil/attributes.h
INSTALL libavutil/audio_fifo.h
INSTALL libavutil/audioconvert.h
INSTALL libavutil/avassert.h
INSTALL libavutil/avstring.h
INSTALL libavutil/avutil.h
INSTALL libavutil/base64.h
INSTALL libavutil/blowfish.h
INSTALL libavutil/bprint.h
INSTALL libavutil/bswap.h
INSTALL libavutil/buffer.h
INSTALL libavutil/channel_layout.h
INSTALL libavutil/common.h
INSTALL libavutil/cpu.h
INSTALL libavutil/crc.h
INSTALL libavutil/error.h
INSTALL libavutil/eval.h
INSTALL libavutil/fifo.h
INSTALL libavutil/file.h
INSTALL libavutil/frame.h
INSTALL libavutil/hmac.h
INSTALL libavutil/imgutils.h
INSTALL libavutil/intfloat.h
INSTALL libavutil/intfloat_readwrite.h
INSTALL libavutil/intreadwrite.h
INSTALL libavutil/lfg.h
INSTALL libavutil/log.h
INSTALL libavutil/mathematics.h
INSTALL libavutil/md5.h
INSTALL libavutil/mem.h
INSTALL libavutil/murmur3.h
INSTALL libavutil/dict.h
INSTALL libavutil/old_pix_fmts.h
INSTALL libavutil/opt.h
INSTALL libavutil/parseutils.h
INSTALL libavutil/pixdesc.h
INSTALL libavutil/pixfmt.h
INSTALL libavutil/random_seed.h
INSTALL libavutil/rational.h
INSTALL libavutil/ripemd.h
INSTALL libavutil/samplefmt.h
INSTALL libavutil/sha.h
INSTALL libavutil/sha512.h
INSTALL libavutil/time.h
INSTALL libavutil/timecode.h
INSTALL libavutil/timestamp.h
INSTALL libavutil/version.h
INSTALL libavutil/xtea.h
INSTALL libavutil/lzo.h
INSTALL libavutil/avconfig.h
INSTALL libavutil/libavutil.pc
link ffmpeg.
二、新建一个Android工程，在工程目录下新建一个jni文件夹，在文件夹下新建一个ffmpeg文件夹，用来放ffmpeg相关的头文件。在ffmpeg文件夹下新建Android.mk文件用来预先加载ffmpeg动态库。Android.mk文件内容如下：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg
LOCAL_SRC_FILES := /path/to/build/output/libffmpeg.so
include $(PREBUILT_SHARED_LIBRARY)
三、在jni下新建Android.mk文件和Application.mk两个文件用来指定编译的顺序和编译的平台以及对应的cpu指令集。
Application.mk
APP_ABI := armeabi
APP_PLATFORM := android-9
Android.mk
include $(call all-subdir-makefiles)
四、编写JNI文件，用来绑定java文件与.c文件的交互，文件内容如下：
/*
* ffmpeg_jni.c
*
* Created on: Sep 1, 2014
* Author: clarck
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <jni.h>
#include "../include/ffmpeg_logger.h"
#include "../include/ffmpeg.h"
// 指定要注册的类，对应完整的java类名
#define JNIREG_CLASS "com/clarck/android/ffmpeg/MainActivity"
JNIEXPORT void JNICALL native_setDataSource(JNIEnv *env, jclass classzz, jstring path) {
char *filepath = ffmpeg_jstringTostr(env, path);
ffmpeg_setDataSource(filepath);
}
//Java和JNI函数的绑定
static JNINativeMethod method_table[] = {
{ "setDataSource", "(Ljava/lang/String;)V", native_setDataSource }
};
//注册native方法到java中
static int registerNativeMethods(JNIEnv *env, const char *className,
JNINativeMethod *gMethods, int numMethods) {
jclass clazz;
clazz = (*env)->FindClass(env, className);
if (clazz == NULL) {
return JNI_FALSE;
}
if ((*env)->RegisterNatives(env, clazz, gMethods, numMethods) < 0) {
return JNI_FALSE;
}
return JNI_TRUE;
}
//调用注册方法
int register_ndk_load(JNIEnv *env) {
return registerNativeMethods(env, JNIREG_CLASS, method_table,
(int) (sizeof(method_table) / sizeof(method_table[0])));
}
JNIEXPORT jint JNI_OnLoad(JavaVM *vm, void *reserved) {
JNIEnv *env = NULL;
jint result = -1;
if ((*vm)->GetEnv(vm, (void**)&env, JNI_VERSION_1_6) != JNI_OK) {
return result;
}
register_ndk_load(env);
//返回JNI的版本
return JNI_VERSION_1_6;
}
五、编写ffmpeg调用函数，内容如下：
/*
* ffmpeg.c
*
* Created on: Sep 1, 2014
* Author: clarck
*/
#include <jni.h>
#include <android/native_window_jni.h>
#include "../include/ffmpeg.h"
#include "../include/ffmpeg_logger.h"
#include "../ffmpeg/include/libavcodec/avcodec.h"
#include "../ffmpeg/include/libavformat/avformat.h"
#include "../ffmpeg/include/libavutil/pixfmt.h"
#include "../ffmpeg/include/libswscale/swscale.h"
char* ffmpeg_jstringTostr(JNIEnv* env, jstring jstr) {
char* pStr = NULL;
jclass jstrObj = (*env)->FindClass(env, "java/lang/String");
jstring encode = (*env)->NewStringUTF(env, "utf-8");
jmethodID methodId = (*env)->GetMethodID(env, jstrObj, "getBytes",
"(Ljava/lang/String;)[B");
jbyteArray byteArray = (jbyteArray) (*env)->CallObjectMethod(env, jstr,
methodId, encode);
jsize strLen = (*env)->GetArrayLength(env, byteArray);
jbyte *jBuf = (*env)->GetByteArrayElements(env, byteArray, JNI_FALSE);
if (jBuf > 0) {
pStr = (char*) malloc(strLen + 1);
if (!pStr) {
return NULL ;
}
memcpy(pStr, jBuf, strLen);
pStr[strLen] = 0;
}
(*env)->ReleaseByteArrayElements(env, byteArray, jBuf, 0);
return pStr;
}
void ffmpeg_setDataSource(char *file_path) {
LOGI("ffmpeg_setDataSource:%s", file_path);
AVFormatContext *pFormatCtx;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame, *pFrameYUV;
AVPacket *packet;
uint8_t *out_buffer;
static struct SwsContext *img_convert_ctx;
int videoStream, i, numBytes;
int ret, got_picture;
av_register_all();
pFormatCtx = avformat_alloc_context();
if (avformat_open_input(&pFormatCtx, file_path, NULL, NULL) != 0) {
LOGE("can‘t open the file. \n");
return;
}
if (avformat_find_stream_info(pFormatCtx, NULL) < 0) {
LOGE("Could‘t find stream infomation.\n");
return;
}
videoStream = 1;
for (i = 0; i < pFormatCtx->nb_streams; i++) {
if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
videoStream = i;
}
}
if (videoStream == -1) {
LOGE("Didn‘t find a video stream.\n");
return;
}
pCodecCtx = pFormatCtx->streams[videoStream]->codec;
pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
if (pCodec == NULL) {
LOGE("Codec not found.\n");
return;
}
if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) {
LOGE("Could not open codec.\n");
return;
}
pFrame = av_frame_alloc();
pFrameYUV = av_frame_alloc();
numBytes = avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx->width,
pCodecCtx->height);
out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
avpicture_fill((AVPicture *) pFrameYUV, out_buffer, AV_PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
int y_size = pCodecCtx->width * pCodecCtx->height;
packet = (AVPacket *) malloc(sizeof(AVPacket));
av_new_packet(packet, y_size);
av_mp_format(pFormatCtx, 0, file_path, 0);
while (av_read_frame(pFormatCtx, packet) >= 0) {
if (packet->stream_index == videoStream) {
ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture,
packet);
LOGI("avcodec_decode_video2 ret:%d", ret);
if (ret < 0) {
LOGE("decode error.\n");
return;
}
if (got_picture) {
//TODO 此处可以将解码出来的图片保存起来。
}
}
av_free_packet(packet);
}
av_free(out_buffer);
av_free(pFrameYUV);
avcodec_close(pCodecCtx);
avformat_close_input(&pFormatCtx);
}
六、编写Android.mk用来编译相关的.c文件，内容如下：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
FFMPEG_PATH := ../ffmpeg
LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(FFMPEG_PATH)/include
LOCAL_MODULE := ffmpeg_player
LOCAL_SRC_FILES += ffmpeg_jni.c
LOCAL_SRC_FILES += ffmpeg.c
LOCAL_SHARED_LIBRARIES := ffmpeg
LOCAL_LDLIBS := -llog
include $(BUILD_SHARED_LIBRARY)
七、编写java文件中相关执行调用方法
package com.clarck.android.ffmpeg;
import android.app.Activity;
import android.os.Bundle;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setDataSource("/sdcard/a.mp4");
}
public native void setDataSource(String path);
static {
System.loadLibrary("ffmpeg");
System.loadLibrary("ffmpeg_player");
}
}
④ 安卓是怎样调用max进行解码的
在Android中，OpenMax IL层，通常可以用于多媒体引擎的插件，Android的多媒体引擎OpenCore和StageFright都可以使用OpenMax作为插件，主要用于编解码（Codec）处理。在Android的框架层，也定义了由Android封装的OpenMax接口，和标准的接口概念基本相同，但是使用C++类型的接口，并且使用了Android的Binder IPC机制。Android封装OpenMax的接口被StageFright使用，OpenCore没有使用这个接口，而是使用其他形式对OpenMax IL层接口进行封装。
⑤ 安卓工程怎么利用第三方库，就是自己用C++编写的编码解码程序，对图片进行编码解码
你可以尝试将构造函数和析构函数一起导出,并且,将编译DLL文件时生成的LIB文件添加到调用DLL的项目中.
如果还不行,请将定义DLL的头文件贴出来分析.
------------------------------------------------------------------
补充:
MFC扩展DLL只能由MFC的应用程序调用,请问你调用DLL的程序是什么类型?
⑥ android中怎么对音频数据pcm进行解码
工程代码结构较为简单：
简单说下思路，先把PCM音频数据从指定的路径文件读到内存，然后给AudioPlayer设置数据源，音频参数等，最后执行播放，暂停，停止等操作
贴上部分类代码片段：
publicclassAudioParam{
intmFrequency;//采样率
intmChannel;//声道
intmSampBit;//采样精度
}
publicinterfacePlayState{
publicstaticfinalintMPS_UNINIT=0;//未就绪
publicstaticfinalintMPS_PREPARE=1;//准备就绪(停止)
publicstaticfinalintMPS_PLAYING=2;//播放中
publicstaticfinalintMPS_PAUSE=3;//暂停
}
⑦ 在Android系统中如何调用系统自带的视频解码器
对需要用FF解码的视频类型去掉内部解码勾选
2.在外部解码器中对所选视频选择FF解码器即可
⑧ 在android 平台实现硬解的大侠们，你们是怎么实现硬解码的
1、视频尺寸
一般都能支持176X144/352X288这种尺寸，但是大一些的，640X480就有很多机子不行了，至于为什么，我也不知道。当然，这个尺寸必须和摄像头预览的尺寸一致，预览的尺寸可以枚举一下。
2、颜色空间
根据ANdroid SDK文档，确保所有硬件平台都支持的颜色，在摄像头预览输出是YUV12，在编码器输入是COLOR_FormatYUV420Planar，也就是前面代码中设置的那样。 不过，文档终究是文档，否则安卓就不是安卓。
在有的平台上，这两个颜色格式是一样的，摄像头的输出可以直接作为编码器的输入。也有的平台，两个是不一样的，前者就是YUV12，后者等于I420，需要把前者的UV分量颠倒一下。
byte[] i420bytes = null;
private byte[] swapYV12toI420(byte[] yv12bytes, int width, int height) {
if (i420bytes == null)
i420bytes = new byte[yv12bytes.length];
for (int i = 0; i < width*height; i++)
i420bytes[i] = yv12bytes[i];
for (int i = width*height; i < width*height + (width/2*height/2); i++)
i420bytes[i] = yv12bytes[i + (width/2*height/2)];
for (int i = width*height + (width/2*height/2); i < width*height + 2*(width/2*height/2); i++)
i420bytes[i] = yv12bytes[i - (width/2*height/2)];
return i420bytes;
}
3、输入输出缓冲区的格式
SDK里并没有规定格式，但是，这种情况H264的格式基本上就是附录B。但是，也有比较有特色的，它就是不带那个StartCode，就是那个0x000001，搞得把他编码器编出来的东西送给他的解码器。
ByteBuffer outputBuffer = outputBuffers[outputBufferIndex];
byte[] outData = new byte[bufferInfo.size + 3];
outputBuffer.get(outData, 3, bufferInfo.size);
if (frameListener != null) {
if ((outData[3]==0 && outData[4]==0 && outData[5]==1)
|| (outData[3]==0 && outData[4]==0 && outData[5]==0 && outData[6]==1))
{
frameListener.onFrame(outData, 3, outData.length-3, bufferInfo.flags);
}
else
{
outData[0] = 0;
outData[1] = 0;
outData[2] = 1;
frameListener.onFrame(outData, 0, outData.length, bufferInfo.flags);
}
}
⑨ 安卓开发怎么将和h264文件解码播放
如题所示，我想将摄像头采集的数据进行h.264硬编码，我想知道Android是如何对视频数据进行硬件编码的
目前已经知道的方案有：
1、用Android4.1 API MediaCodec来对视频数据进行编码
http://stackoverflow.com/q/17232477/2293921
此种方式我测试了，并未成功，目前一直卡在这里，如果你等帮助我，我将非常感激
2、通过MediaRecorder方式对数据进行编码
具体可参考 http://blog.csdn.net/zblue78/article/details/6083374
3、通过移植ffmpeg
这种方式没接触过，也不了解
可能还有一些其他的方式来对视频硬编码，如果你了解一下，感谢分享!
综上，我更倾向于1的方式去做
我来回答
Android , MediaCodec , 硬编码
post_newreply
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⑩ 安卓模拟器怎样解码
把安卓模拟器上app的默认解码改成硬件解码，但是点不动，下载了解码器也没用。相比其他安卓模拟器还有一个最重要的优点说掉了：没有边框，没有黑边，真正全屏。
把它设置成开机自启动，就是使用体验最近似安卓盒子的模拟器了。