<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">前面有博客讲到linux下编译ffmpeg</span>
那么编译完成之后应该怎么使用呢？
在参考了ffmpeg解码文件的demo这里给出一个解码的so库JNI实现方法
在编译完成ffmpeg的源码后，新建一个工程如下图目录结构
在ffmpeg编译后的源码中include文件夹中拷贝上述头文件，然后将编译出的so库拷贝至prebuilt文件夹
新建Android.mk
内容如下：
LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := avutil-54-prebuilt LOCAL_SRC_FILES := prebuilt/libavutil-54.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := avswresample-1-prebuilt LOCAL_SRC_FILES := prebuilt/libswresample-1.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := swscale-3-prebuilt LOCAL_SRC_FILES := prebuilt/libswscale-3.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := avcodec-56-prebuilt LOCAL_SRC_FILES := prebuilt/libavcodec-56.so include $(PREBUILT_SHARED_LIBRARY) #include $(CLEAR_VARS) #LOCAL_MODULE := avdevice-56-prebuilt #LOCAL_SRC_FILES := prebuilt/libavdevice-56.so #include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := avformat-56-prebuilt LOCAL_SRC_FILES := prebuilt/libavformat-56.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := avfilter-5-prebuilt LOCAL_SRC_FILES := prebuilt/libavfilter-5.so include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE := libffmpegutil LOCAL_SRC_FILES := FFmpeg.c LOCAL_LDLIBS := -llog -ljnigraphics -lz -landroid -lm -pthread LOCAL_SHARED_LIBRARIES := avcodec-56-prebuilt avdevice-56-prebuilt avfilter-5-prebuilt avformat-56-prebuilt avutil-54-prebuilt avswresample-1-prebuilt swscale-3-prebuilt include $(BUILD_SHARED_LIBRARY)
APP_ABI := armeabi-v7a APP_PLATFORM := android-9
package com.android;
import android.util.Log;
public class FFmpeg {
static {
try {
System.loadLibrary("avutil-54");
System.loadLibrary("swresample-1");
System.loadLibrary("swscale-3");
System.loadLibrary("avcodec-56");
System.loadLibrary("avformat-56");
System.loadLibrary("avfilter-5");
System.loadLibrary("ffmpegutils");
} catch (UnsatisfiedLinkError ule) {
Log.d("FFMPEG", ule.getMessage());
}
}
public native int H264DecoderInit(int width, int height);
public native int H264DecoderRelease();
public native int H264Decode(byte[] in, int insize, byte[] out);
public native int GetFFmpegVersion();
}
生成头文件:
定位到FFmpeg.class目录， cmd中运行 javah -jni com.android.FFmpeg.class 生成 com_android_FFmpeg.h
#include <math.h>
#include <libavutil/opt.h>
#include <libavcodec/avcodec.h>
#include <libavutil/channel_layout.h>
#include <libavutil/common.h>
#include <libavutil/imgutils.h>
#include <libavutil/mathematics.h>
#include <libavutil/samplefmt.h>
#include <android/log.h>
#include "com_android_FFmpeg.h"
#define LOG_TAG "H264Android.c"
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG,LOG_TAG,__VA_ARGS__)
#ifdef __cplusplus
extern "C" {
#endif
//Video
struct AVCodecContext *pAVCodecCtx = NULL;
struct AVCodec *pAVCodec;
struct AVPacket mAVPacket;
struct AVFrame *pAVFrame = NULL;
//Audio
struct AVCodecContext *pAUCodecCtx = NULL;
struct AVCodec *pAUCodec;
struct AVPacket mAUPacket;
struct AVFrame *pAUFrame = NULL;
int iWidth = 0;
int iHeight = 0;
int *colortab = NULL;
int *u_b_tab = NULL;
int *u_g_tab = NULL;
int *v_g_tab = NULL;
int *v_r_tab = NULL;
//short *tmp_pic=NULL;
unsigned int *rgb_2_pix = NULL;
unsigned int *r_2_pix = NULL;
unsigned int *g_2_pix = NULL;
unsigned int *b_2_pix = NULL;
void DeleteYUVTab() {
// av_free(tmp_pic);
av_free(colortab);
av_free(rgb_2_pix);
}
void CreateYUVTab_16() {
int i;
int u, v;
// tmp_pic = (short*)av_malloc(iWidth*iHeight*2); // 缂傛挸鐡? iWidth * iHeight * 16bits
colortab = (int *) av_malloc(4 * 256 * sizeof(int));
u_b_tab = &colortab[0 * 256];
u_g_tab = &colortab[1 * 256];
v_g_tab = &colortab[2 * 256];
v_r_tab = &colortab[3 * 256];
for (i = 0; i < 256; i++) {
u = v = (i - 128);
u_b_tab[i] = (int) (1.772 * u);
u_g_tab[i] = (int) (0.34414 * u);
v_g_tab[i] = (int) (0.71414 * v);
v_r_tab[i] = (int) (1.402 * v);
}
rgb_2_pix = (unsigned int *) av_malloc(3 * 768 * sizeof(unsigned int));
r_2_pix = &rgb_2_pix[0 * 768];
g_2_pix = &rgb_2_pix[1 * 768];
b_2_pix = &rgb_2_pix[2 * 768];
for (i = 0; i < 256; i++) {
r_2_pix[i] = 0;
g_2_pix[i] = 0;
b_2_pix[i] = 0;
}
for (i = 0; i < 256; i++) {
r_2_pix[i + 256] = (i & 0xF8) << 8;
g_2_pix[i + 256] = (i & 0xFC) << 3;
b_2_pix[i + 256] = (i) >> 3;
}
for (i = 0; i < 256; i++) {
r_2_pix[i + 512] = 0xF8 << 8;
g_2_pix[i + 512] = 0xFC << 3;
b_2_pix[i + 512] = 0x1F;
}
r_2_pix += 256;
g_2_pix += 256;
b_2_pix += 256;
}
void DisplayYUV_16(unsigned int *pdst1, unsigned char *y, unsigned char *u,
unsigned char *v, int width, int height, int src_ystride,
int src_uvstride, int dst_ystride) {
int i, j;
int r, g, b, rgb;
int yy, ub, ug, vg, vr;
unsigned char* yoff;
unsigned char* uoff;
unsigned char* voff;
unsigned int* pdst = pdst1;
int width2 = width / 2;
int height2 = height / 2;
if (width2 > iWidth / 2) {
width2 = iWidth / 2;
y += (width - iWidth) / 4 * 2;
u += (width - iWidth) / 4;
v += (width - iWidth) / 4;
}
if (height2 > iHeight)
height2 = iHeight;
for (j = 0; j < height2; j++) {
yoff = y + j * 2 * src_ystride;
uoff = u + j * src_uvstride;
voff = v + j * src_uvstride;
for (i = 0; i < width2; i++) {
yy = *(yoff + (i << 1));
ub = u_b_tab[*(uoff + i)];
ug = u_g_tab[*(uoff + i)];
vg = v_g_tab[*(voff + i)];
vr = v_r_tab[*(voff + i)];
b = yy + ub;
g = yy - ug - vg;
r = yy + vr;
rgb = r_2_pix[r] + g_2_pix[g] + b_2_pix[b];
yy = *(yoff + (i << 1) + 1);
b = yy + ub;
g = yy - ug - vg;
r = yy + vr;
pdst[(j * dst_ystride + i)] = (rgb)
+ ((r_2_pix[r] + g_2_pix[g] + b_2_pix[b]) << 16);
yy = *(yoff + (i << 1) + src_ystride);
b = yy + ub;
g = yy - ug - vg;
r = yy + vr;
rgb = r_2_pix[r] + g_2_pix[g] + b_2_pix[b];
yy = *(yoff + (i << 1) + src_ystride + 1);
b = yy + ub;
g = yy - ug - vg;
r = yy + vr;
pdst[((2 * j + 1) * dst_ystride + i * 2) >> 1] = (rgb)
+ ((r_2_pix[r] + g_2_pix[g] + b_2_pix[b]) << 16);
}
}
}
/*
* Class: FFmpeg
* Method: H264DecoderInit
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_com_android_FFmpeg_H264DecoderInit(
JNIEnv * env, jobject jobj, jint width, jint height) {
iWidth = width;
iHeight = height;
if (pAVCodecCtx != NULL) {
avcodec_close(pAVCodecCtx);
pAVCodecCtx = NULL;
}
if (pAVFrame != NULL) {
av_free(pAVFrame);
pAVFrame = NULL;
}
// Register all formats and codecs
av_register_all();
LOGD("avcodec register success");
//CODEC_ID_PCM_ALAW
pAVCodec = avcodec_find_decoder(AV_CODEC_ID_H264);
if (pAVCodec == NULL)
return -1;
//init AVCodecContext
pAVCodecCtx = avcodec_alloc_context3(pAVCodec);
if (pAVCodecCtx == NULL)
return -1;
/* we do not send complete frames */
if (pAVCodec->capabilities & CODEC_CAP_TRUNCATED)
pAVCodecCtx->flags |= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */
/* open it */
if (avcodec_open2(pAVCodecCtx, pAVCodec, NULL) < 0)
return avcodec_open2(pAVCodecCtx, pAVCodec, NULL);
av_init_packet(&mAVPacket);
pAVFrame = av_frame_alloc();
if (pAVFrame == NULL)
return -1;
//pImageConvertCtx = sws_getContext(pAVCodecCtx->width, pAVCodecCtx->height, PIX_FMT_YUV420P, pAVCodecCtx->width, pAVCodecCtx->height,PIX_FMT_RGB565LE, SWS_BICUBIC, NULL, NULL, NULL);
//LOGD("sws_getContext return =%d",pImageConvertCtx);
LOGD("avcodec context success");
CreateYUVTab_16();
LOGD("create yuv table success");
return 1;
}
/*
* Class: com_android_concox_FFmpeg
* Method: H264DecoderRelease
* Signature: ()I
*/
JNIEXPORT jint JNICALL Java_com_android_FFmpeg_H264DecoderRelease(
JNIEnv * env, jobject jobj) {
if (pAVCodecCtx != NULL) {
avcodec_close(pAVCodecCtx);
pAVCodecCtx = NULL;
}
if (pAVFrame != NULL) {
av_free(pAVFrame);
pAVFrame = NULL;
}
DeleteYUVTab();
return 1;
}
/*
* Class: com_android_concox_FFmpeg
* Method: H264Decode
* Signature: ([BI[B)I
*/
JNIEXPORT jint JNICALL Java_com_android_FFmpeg_H264Decode(JNIEnv* env,
jobject thiz, jbyteArray in, jint inbuf_size, jbyteArray out) {
int i;
jbyte * inbuf = (jbyte*) (*env)->GetByteArrayElements(env, in, 0);
jbyte * Picture = (jbyte*) (*env)->GetByteArrayElements(env, out, 0);
av_frame_unref(pAVFrame);
mAVPacket.data = inbuf;
mAVPacket.size = inbuf_size;
LOGD("mAVPacket.size:%d\n ", mAVPacket.size);
int len = -1, got_picture = 0;
len = avcodec_decode_video2(pAVCodecCtx, pAVFrame, &got_picture,
&mAVPacket);
LOGD("len:%d\n", len);
if (len < 0) {
LOGD("len=-1,decode error");
return len;
}
if (got_picture > 0) {
LOGD("GOT PICTURE");
/*pImageConvertCtx = sws_getContext (pAVCodecCtx->width,
pAVCodecCtx->height, pAVCodecCtx->pix_fmt,
pAVCodecCtx->width, pAVCodecCtx->height,
PIX_FMT_RGB565LE, SWS_BICUBIC, NULL, NULL, NULL);
sws_scale (pImageConvertCtx, pAVFrame->data, pAVFrame->linesize,0, pAVCodecCtx->height, pAVFrame->data, pAVFrame->linesize);
*/
DisplayYUV_16((int*) Picture, pAVFrame->data[0], pAVFrame->data[1],
pAVFrame->data[2], pAVCodecCtx->width, pAVCodecCtx->height,
pAVFrame->linesize[0], pAVFrame->linesize[1], iWidth);
} else
LOGD("GOT PICTURE fail");
(*env)->ReleaseByteArrayElements(env, in, inbuf, 0);
(*env)->ReleaseByteArrayElements(env, out, Picture, 0);
return len;
}
/*
* Class: com_android_concox_FFmpeg
* Method: GetFFmpegVersion
* Signature: ()I
*/
JNIEXPORT jint JNICALL Java_com_android_concox_FFmpeg_GetFFmpegVersion(
JNIEnv * env, jobject jobj) {
return avcodec_version();
}
#ifdef __cplusplus
}
#endif
配置好Eclipse中的NDK，build即可生成ffmpeguitl库文件。
原文地址：http://blog.csdn.net/devil__lee/article/details/40649569
