本文记录一个安卓平台下基于FFmpeg的视频解码器。该视频解码器C语言的源代码来自于《最简单的基于FFMPEG+SDL的视频播放器》。相关的概念就不再重复记录了。
源代码
项目的目录结构如图所示。Java源代码位于src目录，而C代码位于jni目录。
Android程序Java端代码位于src\com\leixiaohua1020\sffmpegandroiddecoder\MainActivity.java，如下所示。
/**
* 最简单的基于FFmpeg的视频解码器-安卓
* Simplest FFmpeg Android Decoder
*
* 雷霄骅 Lei Xiaohua
* [email protected]
* 中国传媒大学/数字电视技术
* Communication University of China / Digital TV Technology
* http://blog.csdn.net/leixiaohua1020
*
* 本程序是安卓平台下最简单的基于FFmpeg的视频解码器。它可以将输入的视频数据解码成YUV像素数据。
*
* This software is the simplest decoder based on FFmpeg in Android. It can decode video stream
* to raw YUV data.
*
*/
package com.leixiaohua1020.sffmpegandroiddecoder;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.text.Editable;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button startButton = (Button) this.findViewById(R.id.button_start);
final EditText urlEdittext_input= (EditText) this.findViewById(R.id.input_url);
final EditText urlEdittext_output= (EditText) this.findViewById(R.id.output_url);
startButton.setOnClickListener(new OnClickListener() {
public void onClick(View arg0){
String folderurl=Environment.getExternalStorageDirectory().getPath();
String urltext_input=urlEdittext_input.getText().toString();
String inputurl=folderurl+"/"+urltext_input;
String urltext_output=urlEdittext_output.getText().toString();
String outputurl=folderurl+"/"+urltext_output;
Log.i("inputurl",inputurl);
Log.i("outputurl",outputurl);
decode(inputurl,outputurl);
}
});
}
@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;
}
//JNI
public native int decode(String inputurl, String outputurl);
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("sffdecoder");
}
}
C语言端源代码位于jni/simplest_ffmpeg_decoder.c，如下所示。
/**
* 最简单的基于FFmpeg的视频解码器-安卓
* Simplest FFmpeg Android Decoder
*
* 雷霄骅 Lei Xiaohua
* [email protected]
* 中国传媒大学/数字电视技术
* Communication University of China / Digital TV Technology
* http://blog.csdn.net/leixiaohua1020
*
* 本程序是安卓平台下最简单的基于FFmpeg的视频解码器。它可以将输入的视频数据解码成YUV像素数据。
*
* This software is the simplest decoder based on FFmpeg in Android. It can decode video stream
* to raw YUV data.
*
*/
#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
//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_leixiaohua1020_sffmpegandroiddecoder_MainActivity_decode
(JNIEnv *env, jobject obj, jstring input_jstr, jstring output_jstr)
{
AVFormatContext *pFormatCtx;
int i, videoindex;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame,*pFrameYUV;
uint8_t *out_buffer;
AVPacket *packet;
int y_size;
int ret, got_picture;
struct SwsContext *img_convert_ctx;
FILE *fp_yuv;
int frame_cnt;
clock_t time_start, time_finish;
double time_duration = 0.0;
char input_str[500]={0};
char output_str[500]={0};
char info[1000]={0};
sprintf(input_str,"%s",(*env)->GetStringUTFChars(env,input_jstr, NULL));
sprintf(output_str,"%s",(*env)->GetStringUTFChars(env,output_jstr, NULL));
//FFmpeg av_log() callback
av_log_set_callback(custom_log);
av_register_all();
avformat_network_init();
pFormatCtx = avformat_alloc_context();
if(avformat_open_input(&pFormatCtx,input_str,NULL,NULL)!=0){
LOGE("Couldn‘t open input stream.\n");
return -1;
}
if(avformat_find_stream_info(pFormatCtx,NULL)<0){
LOGE("Couldn‘t find stream information.\n");
return -1;
}
videoindex=-1;
for(i=0; i<pFormatCtx->nb_streams; i++)
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
videoindex=i;
break;
}
if(videoindex==-1){
LOGE("Couldn‘t find a video stream.\n");
return -1;
}
pCodecCtx=pFormatCtx->streams[videoindex]->codec;
pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
if(pCodec==NULL){
LOGE("Couldn‘t find Codec.\n");
return -1;
}
if(avcodec_open2(pCodecCtx, pCodec,NULL)<0){
LOGE("Couldn‘t open codec.\n");
return -1;
}
pFrame=av_frame_alloc();
pFrameYUV=av_frame_alloc();
out_buffer=(uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));
avpicture_fill((AVPicture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
packet=(AVPacket *)av_malloc(sizeof(AVPacket));
img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
pCodecCtx->width, pCodecCtx->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
sprintf(info, "[Input ]%s\n", input_str);
sprintf(info, "%s[Output ]%s\n",info,output_str);
sprintf(info, "%s[Format ]%s\n",info, pFormatCtx->iformat->name);
sprintf(info, "%s[Codec ]%s\n",info, pCodecCtx->codec->name);
sprintf(info, "%s[Resolution]%dx%d\n",info, pCodecCtx->width,pCodecCtx->height);
fp_yuv=fopen(output_str,"wb+");
if(fp_yuv==NULL){
printf("Cannot open output file.\n");
return -1;
}
frame_cnt=0;
time_start = clock();
while(av_read_frame(pFormatCtx, packet)>=0){
if(packet->stream_index==videoindex){
ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
if(ret < 0){
LOGE("Decode Error.\n");
return -1;
}
if(got_picture){
sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height,
pFrameYUV->data, pFrameYUV->linesize);
y_size=pCodecCtx->width*pCodecCtx->height;
fwrite(pFrameYUV->data[0],1,y_size,fp_yuv); //Y
fwrite(pFrameYUV->data[1],1,y_size/4,fp_yuv); //U
fwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv); //V
//Output info
char pictype_str[10]={0};
switch(pFrame->pict_type){
case AV_PICTURE_TYPE_I:sprintf(pictype_str,"I");break;
case AV_PICTURE_TYPE_P:sprintf(pictype_str,"P");break;
case AV_PICTURE_TYPE_B:sprintf(pictype_str,"B");break;
default:sprintf(pictype_str,"Other");break;
}
LOGI("Frame Index: %5d. Type:%s",frame_cnt,pictype_str);
frame_cnt++;
}
}
av_free_packet(packet);
}
//flush decoder
//FIX: Flush Frames remained in Codec
while (1) {
ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
if (ret < 0)
break;
if (!got_picture)
break;
sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height,
pFrameYUV->data, pFrameYUV->linesize);
int y_size=pCodecCtx->width*pCodecCtx->height;
fwrite(pFrameYUV->data[0],1,y_size,fp_yuv); //Y
fwrite(pFrameYUV->data[1],1,y_size/4,fp_yuv); //U
fwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv); //V
//Output info
char pictype_str[10]={0};
switch(pFrame->pict_type){
case AV_PICTURE_TYPE_I:sprintf(pictype_str,"I");break;
case AV_PICTURE_TYPE_P:sprintf(pictype_str,"P");break;
case AV_PICTURE_TYPE_B:sprintf(pictype_str,"B");break;
default:sprintf(pictype_str,"Other");break;
}
LOGI("Frame Index: %5d. Type:%s",frame_cnt,pictype_str);
frame_cnt++;
}
time_finish = clock();
time_duration=(double)(time_finish - time_start);
sprintf(info, "%s[Time ]%fms\n",info,time_duration);
sprintf(info, "%s[Count ]%d\n",info,frame_cnt);
sws_freeContext(img_convert_ctx);
fclose(fp_yuv);
av_frame_free(&pFrameYUV);
av_frame_free(&pFrame);
avcodec_close(pCodecCtx);
avformat_close_input(&pFormatCtx);
return 0;
}
Android.mk文件位于jni/Android.mk，如下所示。
# Android.mk for FFmpeg # # Lei Xiaohua 雷霄骅 # [email protected] # http://blog.csdn.net/leixiaohua1020 # 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 := sffdecoder LOCAL_SRC_FILES :=simplest_ffmpeg_decoder.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)
运行结果
App在手机上运行后的结果如下图所示。
单机“Start”按钮就可以将存储卡根目录中的视频文件解码为YUV文件（需要等待一段时间完成解码）。注意解码后的YUV文件体积巨大，可能会占用大量的存储卡空间。
下载
simplest ffmpeg mobile
项目主页
Github：https://github.com/leixiaohua1020/simplest_ffmpeg_mobile
开源中国：https://git.oschina.net/leixiaohua1020/simplest_ffmpeg_mobile
CSDN工程下载地址：http://download.csdn.net/detail/leixiaohua1020/8924391
本解决方案包含了使用FFmpeg在移动端处理多媒体的各种例子：
[Android]
simplest_android_player: 基于安卓接口的视频播放器
simplest_ffmpeg_android_helloworld: 安卓平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_android_decoder: 安卓平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_android_decoder_onelib: 安卓平台下最简单的基于FFmpeg的视频解码器-单库版
simplest_ffmpeg_android_streamer: 安卓平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_android_transcoder: 安卓平台下移植的FFmpeg命令行工具
simplest_sdl_android_helloworld: 移植SDL到安卓平台的最简单程序
[IOS]
simplest_ios_player: 基于IOS接口的视频播放器
simplest_ffmpeg_ios_helloworld: IOS平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_ios_decoder: IOS平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_ios_streamer: IOS平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_ios_transcoder: IOS平台下移植的ffmpeg.c命令行工具
simplest_sdl_ios_helloworld: 移植SDL到IOS平台的最简单程序
版权声明：本文为博主原创文章，未经博主允许不得转载。
时间： 2024-10-11 16:48:51