FFmpeg解碼視訊繪制到螢幕

步驟

1.Android端寫surfaceView，設定視訊格式ARGB，callback,holder，不多說

2.解碼視訊資料，得到一幀一幀的YUV資料（了解視訊解碼流程）

3.通過surfaceView擷取nativewindow

4.lock Window

5.第三方的libyuv to RGBA

6.set buffer

7.unlock Window

實作代碼

#include <jni.h>
#include <android/log.h>
#include <stdlib.h>
#include <stdio.h>
//編解碼相關
#include "libavcodec/avcodec.h"
//封裝格式處理
#include "libavformat/avformat.h"
//像素處理
#include "include/libswscale/swscale.h"
// 自定義頭檔案
#include "com_example_ffmpeg_FfmpegUtil.h"

#define LOGI(FORMAT,...) __android_log_print(ANDROID_LOG_INFO,"render",FORMAT,##__VA_ARGS__);
#define LOGE(FORMAT,...) __android_log_print(ANDROID_LOG_ERROR,"render",FORMAT,##__VA_ARGS__);

JNIEXPORT void JNICALL Java_com_example_rendor_SurfaceUtil_render(JNIEnv *env,
        jclass jclzz, jstring input_jstr, jobject surface) {

    const char *input_cstr = (*env)->GetStringUTFChars(env, input_jstr, NULL);

    // 注冊所有的元件
    av_register_all();
    // 拿到封裝格式上下文
    AVFormatContext * aVFormatContext = avformat_alloc_context();

    // 打開視訊檔案
    int isOpen = avformat_open_input(&aVFormatContext, input_cstr, NULL, NULL);
    if (isOpen < ) {

        LOGE("%s", "打開視訊檔案失敗");
        return;
    }

    LOGE("%s", "avformat_open_input");
    int stream_info = avformat_find_stream_info(aVFormatContext, NULL);
    if (stream_info < ) {

        LOGE("%s", "stream_info失敗");
        return;
    }

    LOGE("%s", "avformat_open_input");

    // 拿到解碼器
    AVCodecContext *aVCodecContext;
    int i = ;
    int index = -;
    for (; i < aVFormatContext->nb_streams; i++) {

        aVCodecContext = aVFormatContext->streams[i]->codec;
        if (aVCodecContext->codec_type == AVMEDIA_TYPE_VIDEO) {

            index = i;
            break;
        }
    }

    if (index == -) {

        LOGE("%s", "沒有找到視訊流");
        return;
    }

    // 找到解碼器
    AVCodec *avcodec = avcodec_find_decoder(
            aVFormatContext->streams[index]->codec->codec_id);
    if (avcodec == NULL) {

        LOGE("%s", "沒有找到解碼器");
        return;
    }

    LOGE("%s", "avcodec_find_decoder");
    // 打開解碼器
    int isOpenCodec = avcodec_open2(aVCodecContext, avcodec, NULL);
    if (isOpenCodec < ) {

        LOGE("%s", "打開解碼器失敗");
        return;
    }

    LOGE("%s", "avcodec_open2");
    //讀取每一祯壓縮資料
    AVPacket *aVPacket = (AVPacket *) av_malloc(sizeof(AVPacket));
    AVFrame *aVFrame = av_frame_alloc();
    AVFrame *rgbFrame = av_frame_alloc();

    // 通過Java的surface對象拿到nativeWindow,處理完成之後需要釋放
    ANativeWindow* native_window = ANativeWindow_fromSurface(env, surface);

    ANativeWindow_Buffer outBuffer;

    LOGE("%s", "初始化緩沖區");
    int got_picture_ptr;
    int frameCount;
    int len;

    while (av_read_frame(aVFormatContext, aVPacket) >= ) {

        LOGE("%s", "av_read_frame");
        len = avcodec_decode_video2(aVCodecContext, aVFrame, &got_picture_ptr,
                aVPacket);
        if (got_picture_ptr) {
            // 擷取到解壓資料

            // 設定nativewindow的緩沖區，width，height來控制緩沖區的大小（像素），buffer會進行相應的縮放來适配螢幕的大小
            ANativeWindow_setBuffersGeometry(native_window,
                    aVCodecContext->width, aVCodecContext->height,
                    WINDOW_FORMAT_RGBA_8888);

            //* Lock the window's next drawing surface for writing.
            int lock = ANativeWindow_lock(native_window, &outBuffer, NULL);

            //初始化緩沖區 這裡把解碼後的視訊frame的緩沖區與nativewindow的緩沖區相關聯
            avpicture_fill((AVPicture *) rgbFrame, outBuffer.bits,
                    PIX_FMT_RGB32, aVCodecContext->width,
                    aVCodecContext->height);
            // 将yuv420的frame轉換成rgb
            int convert = I420ToARGB(aVFrame->data[], aVFrame->linesize[],
                    aVFrame->data[], aVFrame->linesize[], aVFrame->data[],
                    aVFrame->linesize[], rgbFrame->data[],
                    rgbFrame->linesize[], aVCodecContext->width,
                    aVCodecContext->height);

            // * Unlock the window's drawing surface after previously locking it,
            // * posting the new buffer to the display.
            int32_t unlock = ANativeWindow_unlockAndPost(native_window);

            usleep( * );
        }
        av_free_packet(aVPacket);
    }

    avformat_free_context(aVFormatContext);
    avcodec_free_context(&aVCodecContext);
    av_frame_free(&aVFrame);
    av_frame_free(&rgbFrame);
    ANativeWindow_release(native_window);
    (*env)->ReleaseStringUTFChars(env, input_jstr, input_cstr);
}

           

Android.mk

依賴FFmpeg的8個so(實際上用不着)，以及第三方的libyuv（YUV 2 RGB）

LOCAL_PATH := $(call my-dir)

#ffmpeg lib
include $(CLEAR_VARS)
LOCAL_MODULE := avcodec
LOCAL_SRC_FILES := libavcodec-.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := avdevice
LOCAL_SRC_FILES := libavdevice-.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := avfilter
LOCAL_SRC_FILES := libavfilter-.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := avformat
LOCAL_SRC_FILES := libavformat-.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := avutil
LOCAL_SRC_FILES := libavutil-.so
include $(PREBUILT_SHARED_LIBRARY)


include $(CLEAR_VARS)
LOCAL_MODULE := postproc
LOCAL_SRC_FILES := libpostproc-.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := swresample
LOCAL_SRC_FILES := libswresample-.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := swscale
LOCAL_SRC_FILES := libswscale-.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := yuv
LOCAL_SRC_FILES := libyuv.so
include $(PREBUILT_SHARED_LIBRARY)

#myapp
include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg
LOCAL_SRC_FILES := ffmpeg.c
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include/ffmpeg
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include/libyuv
##-landroid參數 for native windows（這行很重要，不要編譯老是報找不到window.h）
LOCAL_LDLIBS := -llog -landroid

LOCAL_SHARED_LIBRARIES := yuv avcodec avdevice avfilter avformat avutil postproc swresample swscale
include $(BUILD_SHARED_LIBRARY)
           

Application.mk

// 指定支援的平台
APP_ABI := armeabi
// 指定platFrom,不指定的話低版本的platform（小于9）會沒有這個頭檔案
APP_PLATFORM := android-