最簡單的基於FFmpeg的移動端例子：Android 視頻解碼器

標籤：ffmpeg   android   視頻解碼   jni   

本文記錄一個安卓平台下基於FFmpeg的視頻解碼器。該視頻解碼器C語言的原始碼來自於《最簡單的基於FFMPEG+SDL的視頻播放器》。相關的概念就不再重複記錄了。

原始碼項目的目錄結構。Java原始碼位於src目錄，而C代碼位於jni目錄。
Android程式Java端代碼位於src\com\leixiaohua1020\sffmpegandroiddecoder\MainActivity.java，如下所示。

/** * 最簡單的基於FFmpeg的視頻解碼器-安卓 * Simplest FFmpeg Android Decoder *  * 雷霄驊 Lei Xiaohua * [email protected] * 中國傳媒大學/數字電視技術 * Communication University of China / Digital TV Technology * http://blog.csdn.net/leixiaohua1020 *  * 本程式是安卓平台下最簡單的基於FFmpeg的視頻解碼器。它可以將輸入的視頻資料解碼成YUV像素資料。 *  * 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語言端原始碼位於jni/simplest_ffmpeg_decoder.c，如下所示。

/** * 最簡單的基於FFmpeg的視頻解碼器-安卓 * Simplest FFmpeg Android Decoder * * 雷霄驊 Lei Xiaohua * [email protected] * 中國傳媒大學/數字電視技術 * Communication University of China / Digital TV Technology * http://blog.csdn.net/leixiaohua1020 * * 本程式是安卓平台下最簡單的基於FFmpeg的視頻解碼器。它可以將輸入的視頻資料解碼成YUV像素資料。 * * 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;inti, 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);  //Ufwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv);  //V//Output infochar 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 Codecwhile (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);  //Ufwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv);  //V//Output infochar 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檔案位於jni/Android.mk，如下所示。

# Android.mk for FFmpeg## Lei Xiaohua 雷霄驊# [email protected]# http://blog.csdn.net/leixiaohua1020# LOCAL_PATH := $(call my-dir)# FFmpeg libraryinclude $(CLEAR_VARS)LOCAL_MODULE := avcodecLOCAL_SRC_FILES := libavcodec-56.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avdeviceLOCAL_SRC_FILES := libavdevice-56.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avfilterLOCAL_SRC_FILES := libavfilter-5.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avformatLOCAL_SRC_FILES := libavformat-56.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := avutilLOCAL_SRC_FILES := libavutil-54.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := postprocLOCAL_SRC_FILES := libpostproc-53.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := swresampleLOCAL_SRC_FILES := libswresample-1.soinclude $(PREBUILT_SHARED_LIBRARY)include $(CLEAR_VARS)LOCAL_MODULE := swscaleLOCAL_SRC_FILES := libswscale-3.soinclude $(PREBUILT_SHARED_LIBRARY)# Programinclude $(CLEAR_VARS)LOCAL_MODULE := sffdecoderLOCAL_SRC_FILES :=simplest_ffmpeg_decoder.cLOCAL_C_INCLUDES += $(LOCAL_PATH)/includeLOCAL_LDLIBS := -llog -lzLOCAL_SHARED_LIBRARIES := avcodec avdevice avfilter avformat avutil postproc swresample swscaleinclude $(BUILD_SHARED_LIBRARY)

運行結果App在手機上運行後的結果如所示。
 
單機“Start”按鈕就可以將儲存卡根目錄中的視頻檔案解碼為YUV檔案（需要等待一段時間完成解碼）。注意解碼後的YUV檔案體積巨大，可能會佔用大量的儲存卡空間。
 
下載
simplest ffmpeg mobile

項目首頁

Github：https://github.com/leixiaohua1020/simplest_ffmpeg_mobile

開源中國：https://git.oschina.net/leixiaohua1020/simplest_ffmpeg_mobile

CSDN工程：http://download.csdn.net/detail/leixiaohua1020/8924391

本方案套件含了使用FFmpeg在移動端處理多媒體的各種例子：

[Android]
simplest_android_player: 基於安卓介面的視頻播放器
simplest_ffmpeg_android_helloworld: 安卓平台下基於FFmpeg的HelloWorld程式
simplest_ffmpeg_android_decoder: 安卓平台下最簡單的基於FFmpeg的視頻解碼器
simplest_ffmpeg_android_decoder_onelib: 安卓平台下最簡單的基於FFmpeg的視頻解碼器-單庫版
simplest_ffmpeg_android_streamer: 安卓平台下最簡單的基於FFmpeg的推流器
simplest_ffmpeg_android_transcoder: 安卓平台下移植的FFmpeg命令列工具
simplest_sdl_android_helloworld: 移植SDL到安卓平台的最簡單程式
[IOS]
simplest_ios_player: 基於IOS介面的視頻播放器
simplest_ffmpeg_ios_helloworld: IOS平台下基於FFmpeg的HelloWorld程式
simplest_ffmpeg_ios_decoder: IOS平台下最簡單的基於FFmpeg的視頻解碼器
simplest_ffmpeg_ios_streamer: IOS平台下最簡單的基於FFmpeg的推流器
simplest_ffmpeg_ios_transcoder: IOS平台下移植的ffmpeg.c命令列工具
simplest_sdl_ios_helloworld: 移植SDL到IOS平台的最簡單程式

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最簡單的基於FFmpeg的移動端例子：Android 視頻解碼器