FFmpeg解码视频绘制到屏幕

步骤

1.Android端写surfaceView，设置视频格式ARGB，callback,holder，不多说
2.解码视频数据，得到一帧一帧的YUV数据（了解视频解码流程）
3.通过surfaceView获取nativewindow
4.lock Window
5.第三方的libyuv to RGBA
6.set buffer
7.unlock Window

实现代码

#include <jni.h>
#include <android/log.h>
#include <stdlib.h>
#include <stdio.h>
//编解码相关
#include "libavcodec/avcodec.h"
//封装格式处理
#include "libavformat/avformat.h"
//像素处理
#include "include/libswscale/swscale.h"
// 自定义头文件
#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);

    // 注册所有的组件
    av_register_all();
    // 拿到封装格式上下文
    AVFormatContext * aVFormatContext = avformat_alloc_context();

    // 打开视频文件
    int isOpen = avformat_open_input(&aVFormatContext, input_cstr, NULL, NULL);
    if (isOpen < 0) {

        LOGE("%s", "打开视频文件失败");
        return;
    }

    LOGE("%s", "avformat_open_input");
    int stream_info = avformat_find_stream_info(aVFormatContext, NULL);
    if (stream_info < 0) {

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

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

    // 拿到解码器
    AVCodecContext *aVCodecContext;
    int i = 0;
    int index = -1;
    for (; i < aVFormatContext->nb_streams; i++) {

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

            index = i;
            break;
        }
    }

    if (index == -1) {

        LOGE("%s", "没有找到视频流");
        return;
    }

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

        LOGE("%s", "没有找到解码器");
        return;
    }

    LOGE("%s", "avcodec_find_decoder");
    // 打开解码器
    int isOpenCodec = avcodec_open2(aVCodecContext, avcodec, NULL);
    if (isOpenCodec < 0) {

        LOGE("%s", "打开解码器失败");
        return;
    }

    LOGE("%s", "avcodec_open2");
    //读取每一祯压缩数据
    AVPacket *aVPacket = (AVPacket *) av_malloc(sizeof(AVPacket));
    AVFrame *aVFrame = av_frame_alloc();
    AVFrame *rgbFrame = av_frame_alloc();

    // 通过Java的surface对象拿到nativeWindow,处理完成之后需要释放
    ANativeWindow* native_window = ANativeWindow_fromSurface(env, surface);

    ANativeWindow_Buffer outBuffer;

    LOGE("%s", "初始化缓冲区");
    int got_picture_ptr;
    int frameCount;
    int len;

    while (av_read_frame(aVFormatContext, aVPacket) >= 0) {

        LOGE("%s", "av_read_frame");
        len = avcodec_decode_video2(aVCodecContext, aVFrame, &got_picture_ptr,
                aVPacket);
        if (got_picture_ptr) {
            // 获取到解压数据

            // 设置nativewindow的缓冲区，width，height来控制缓冲区的大小（像素），buffer会进行相应的缩放来适配屏幕的大小
            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);

            //初始化缓冲区 这里把解码后的视频frame的缓冲区与nativewindow的缓冲区相关联
            avpicture_fill((AVPicture *) rgbFrame, outBuffer.bits,
                    PIX_FMT_RGB32, aVCodecContext->width,
                    aVCodecContext->height);
            // 将yuv420的frame转换成rgb
            int convert = I420ToARGB(aVFrame->data[0], aVFrame->linesize[0],
                    aVFrame->data[2], aVFrame->linesize[2], aVFrame->data[1],
                    aVFrame->linesize[1], rgbFrame->data[0],
                    rgbFrame->linesize[0], 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(16 * 1000);
        }
        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

依赖FFmpeg的8个so(实际上用不着)，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-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)

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参数 for native windows（这行很重要，不要编译老是报找不到window.h）
LOCAL_LDLIBS := -llog -landroid

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

Application.mk

// 指定支持的平台
APP_ABI := armeabi
// 指定platFrom,不指定的话低版本的platform（小于9）会没有这个头文件
APP_PLATFORM := android-9