CentOS 由 JavaCPP 转让 FFMPEG

static void SaveFrame(AVFrame pFrame, int width, int height, int iFrame)  
        throws IOException {  
    // Open file  
    OutputStream stream = new FileOutputStream("frame" + iFrame + ".ppm");

    // Write header  
    stream.write(("P6\\n" + width + " " + height + "\\n255\\n").getBytes());

    // Write pixel data  
    BytePointer data = pFrame.data(0);  
    byte\[\] bytes = new byte\[width \* 3\];  
    int l = pFrame.linesize(0);  
    for (int y = 0; y < height; y++) {  
        data.position(y \* l).get(bytes);  
        stream.write(bytes);  
    }

    // Close file  
    stream.close();  
}

public static void main(String\[\] args) throws IOException {  
    AVFormatContext pFormatCtx = new AVFormatContext(null);  
    int i, videoStream;  
    AVCodecContext pCodecCtx = null;  
    AVCodec pCodec = null;  
    AVFrame pFrame = null;  
    AVFrame pFrameRGB = null;  
    AVPacket packet = new AVPacket();  
    int\[\] frameFinished = new int\[1\];  
    int numBytes;  
    BytePointer buffer = null;

    AVDictionary optionsDict = null;  
    SwsContext sws\_ctx = null;

    if (args.length < 1) {  
        args = new String\[\] { "/root/test.ts" };  
        // System.out.println("Please provide a movie file");  
        // System.exit(-1);  
    }  
    // Register all formats and codecs  
    av\_register\_all();

    // Open video file  
    if (avformat\_open\_input(pFormatCtx, args\[0\], null, null) != 0) {  
        System.exit(-1); // Couldn't open file  
    }

    // Retrieve stream information  
    if (avformat\_find\_stream\_info(pFormatCtx, (PointerPointer) null) < 0) {  
        System.exit(-1); // Couldn't find stream information  
    }

    // Dump information about file onto standard error  
    av\_dump\_format(pFormatCtx, 0, args\[0\], 0);

    // Find the first video stream  
    videoStream = -1;  
    for (i = 0; i < pFormatCtx.nb\_streams(); i++) {  
        if (pFormatCtx.streams(i).codec().codec\_type() == AVMEDIA\_TYPE\_VIDEO) {  
            videoStream = i;  
            break;  
        }  
    }  
    if (videoStream == -1) {  
        System.exit(-1); // Didn't find a video stream  
    }

    // Get a pointer to the codec context for the video stream  
    pCodecCtx = pFormatCtx.streams(videoStream).codec();

    // Find the decoder for the video stream  
    pCodec = avcodec\_find\_decoder(pCodecCtx.codec\_id());  
    if (pCodec == null) {  
        System.err.println("Unsupported codec!");  
        System.exit(-1); // Codec not found  
    }  
    // Open codec  
    if (avcodec\_open2(pCodecCtx, pCodec, optionsDict) < 0) {  
        System.exit(-1); // Could not open codec  
    }

    // Allocate video frame  
    pFrame = av\_frame\_alloc();

    // Allocate an AVFrame structure  
    pFrameRGB = av\_frame\_alloc();  
    if (pFrameRGB == null) {  
        System.exit(-1);  
    }

    // Determine required buffer size and allocate buffer  
    numBytes = avpicture\_get\_size(AV\_PIX\_FMT\_RGB24, pCodecCtx.width(),  
            pCodecCtx.height());  
    buffer = new BytePointer(av\_malloc(numBytes));

    sws\_ctx = sws\_getContext(pCodecCtx.width(), pCodecCtx.height(),  
            pCodecCtx.pix\_fmt(), pCodecCtx.width(), pCodecCtx.height(),  
            AV\_PIX\_FMT\_RGB24, SWS\_BILINEAR, null, null,  
            (DoublePointer) null);

    // Assign appropriate parts of buffer to image planes in pFrameRGB  
    // Note that pFrameRGB is an AVFrame, but AVFrame is a superset  
    // of AVPicture  
    avpicture\_fill(new AVPicture(pFrameRGB), buffer, AV\_PIX\_FMT\_RGB24,  
            pCodecCtx.width(), pCodecCtx.height());

    // Read frames and save first five frames to disk  
    i = 0;  
    while (av\_read\_frame(pFormatCtx, packet) >= 0) {  
        // Is this a packet from the video stream?  
        if (packet.stream\_index() == videoStream) {  
            // Decode video frame  
            avcodec\_decode\_video2(pCodecCtx, pFrame, frameFinished, packet);

            // Did we get a video frame?  
            if (frameFinished\[0\] != 0) {  
                // Convert the image from its native format to RGB  
                sws\_scale(sws\_ctx, pFrame.data(), pFrame.linesize(), 0,  
                        pCodecCtx.height(), pFrameRGB.data(),  
                        pFrameRGB.linesize());

                // Save the frame to disk  
                if (++i <= 5) {  
                    SaveFrame(pFrameRGB, pCodecCtx.width(),  
                            pCodecCtx.height(), i);  
                }  
            }  
        }

        // Free the packet that was allocated by av\_read\_frame  
        av\_free\_packet(packet);  
    }

    // Free the RGB image  
    av\_free(buffer);  
    av\_free(pFrameRGB);

    // Free the YUV frame  
    av\_free(pFrame);

    // Close the codec  
    avcodec\_close(pCodecCtx);

    // Close the video file  
    avformat\_close\_input(pFormatCtx);

    System.exit(0);  
}

}

4）执行实例，得到输出结果：

Input #0, mpegts, from '/root/test.ts':

Duration: 00:03:20.02, start: 0.056778, bitrate: 1455 kb/s

Program 1

Metadata:

service_name : jVideo

service_provider: jTeam

Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p, 960x540 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc

Stream #0:1[0x101]: Audio: aac ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp, 66 kb/s

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