Example #1
0
        private static unsafe void Main(string[] args)
        {
            Console.WriteLine("Runnung in {0}-bit mode.", Environment.Is64BitProcess ? "64" : "32");

            // register path to ffmpeg
            switch (Environment.OSVersion.Platform)
            {
            case PlatformID.Win32NT:
            case PlatformID.Win32S:
            case PlatformID.Win32Windows:
                string ffmpegPath = string.Format(@"../../../FFmpeg/bin/windows/{0}", Environment.Is64BitProcess ? "x64" : "x86");
                InteropHelper.RegisterLibrariesSearchPath(ffmpegPath);
                break;

            case PlatformID.Unix:
            case PlatformID.MacOSX:
                string libraryPath = Environment.GetEnvironmentVariable(InteropHelper.LD_LIBRARY_PATH);
                InteropHelper.RegisterLibrariesSearchPath(libraryPath);
                break;
            }

            // decode 100 frame from url or path

            //string url = @"../../sample_mpeg4.mp4";
            string url = @"http://hubblesource.stsci.edu/sources/video/clips/details/images/centaur_1.mpg";

            FFmpegInvoke.av_register_all();
            FFmpegInvoke.avcodec_register_all();
            FFmpegInvoke.avformat_network_init();


            AVFormatContext *pFormatContext = FFmpegInvoke.avformat_alloc_context();

            if (FFmpegInvoke.avformat_open_input(&pFormatContext, url, null, null) != 0)
            {
                throw new Exception("Could not open file");
            }

            if (FFmpegInvoke.avformat_find_stream_info(pFormatContext, null) != 0)
            {
                throw new Exception("Could not find stream info");
            }

            AVStream *pStream = null;

            for (int i = 0; i < pFormatContext->nb_streams; i++)
            {
                if (pFormatContext->streams[i]->codec->codec_type == AVMediaType.AVMEDIA_TYPE_VIDEO)
                {
                    pStream = pFormatContext->streams[i];
                    break;
                }
            }
            if (pStream == null)
            {
                throw new Exception("Could not found video stream");
            }

            AVCodecContext codecContext    = *(pStream->codec);
            int            width           = codecContext.width;
            int            height          = codecContext.height;
            AVPixelFormat  sourcePixFmt    = codecContext.pix_fmt;
            AVCodecID      codecId         = codecContext.codec_id;
            var            convertToPixFmt = AVPixelFormat.PIX_FMT_BGR24;
            SwsContext *   pConvertContext = FFmpegInvoke.sws_getContext(width, height, sourcePixFmt,
                                                                         width, height, convertToPixFmt,
                                                                         FFmpegInvoke.SWS_FAST_BILINEAR, null, null, null);

            if (pConvertContext == null)
            {
                throw new Exception("Could not initialize the conversion context");
            }

            var pConvertedFrame          = (AVPicture *)FFmpegInvoke.avcodec_alloc_frame();
            int convertedFrameBufferSize = FFmpegInvoke.avpicture_get_size(convertToPixFmt, width, height);
            var pConvertedFrameBuffer    = (byte *)FFmpegInvoke.av_malloc((uint)convertedFrameBufferSize);

            FFmpegInvoke.avpicture_fill(pConvertedFrame, pConvertedFrameBuffer, convertToPixFmt, width, height);

            AVCodec *pCodec = FFmpegInvoke.avcodec_find_decoder(codecId);

            if (pCodec == null)
            {
                throw new Exception("Unsupported codec");
            }

            // Reusing codec context from stream info,
            // as an alternative way it could look like this: (but it works not for all kind of codecs)
            // AVCodecContext* pCodecContext = FFmpegInvoke.avcodec_alloc_context3(pCodec);
            AVCodecContext *pCodecContext = &codecContext;

            if ((pCodec->capabilities & FFmpegInvoke.CODEC_CAP_TRUNCATED) == FFmpegInvoke.CODEC_CAP_TRUNCATED)
            {
                pCodecContext->flags |= FFmpegInvoke.CODEC_FLAG_TRUNCATED;
            }

            if (FFmpegInvoke.avcodec_open2(pCodecContext, pCodec, null) < 0)
            {
                throw new Exception("Could not open codec");
            }

            AVFrame *pDecodedFrame = FFmpegInvoke.avcodec_alloc_frame();

            var       packet  = new AVPacket();
            AVPacket *pPacket = &packet;

            FFmpegInvoke.av_init_packet(pPacket);

            int frameNumber = 0;

            while (frameNumber < 100)
            {
                if (FFmpegInvoke.av_read_frame(pFormatContext, pPacket) < 0)
                {
                    throw new Exception("Could not read frame");
                }

                if (pPacket->stream_index != pStream->index)
                {
                    continue;
                }

                int gotPicture = 0;
                int size       = FFmpegInvoke.avcodec_decode_video2(pCodecContext, pDecodedFrame, &gotPicture, pPacket);
                if (size < 0)
                {
                    throw new Exception(string.Format("Error while decoding frame {0}", frameNumber));
                }

                if (gotPicture == 1)
                {
                    Console.WriteLine("frame: {0}", frameNumber);

                    byte **src = &pDecodedFrame->data_0;
                    byte **dst = &pConvertedFrame->data_0;
                    FFmpegInvoke.sws_scale(pConvertContext, src, pDecodedFrame->linesize, 0,
                                           height, dst, pConvertedFrame->linesize);

                    byte *convertedFrameAddress = pConvertedFrame->data_0;

                    var imageBufferPtr = new IntPtr(convertedFrameAddress);

                    int linesize = pConvertedFrame->linesize[0];
                    using (var bitmap = new Bitmap(width, height, linesize, PixelFormat.Format24bppRgb, imageBufferPtr))
                    {
                        bitmap.Save(@"frame.buffer.jpg", ImageFormat.Jpeg);
                    }

                    frameNumber++;

                    System.Threading.Thread.Sleep(1000);
                }
            }

            FFmpegInvoke.av_free(pConvertedFrame);
            FFmpegInvoke.av_free(pConvertedFrameBuffer);
            FFmpegInvoke.sws_freeContext(pConvertContext);

            FFmpegInvoke.av_free(pDecodedFrame);
            FFmpegInvoke.avcodec_close(pCodecContext);
            FFmpegInvoke.avformat_close_input(&pFormatContext);
        }