public static unsafe void GetFrame(string url, double request_time)
{
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 = @"test.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;
int stream_index = 0;
for (int i = 0; i < pFormatContext->nb_streams; i++)
{
if (pFormatContext->streams[i]->codec->codec_type == AVMediaType.AVMEDIA_TYPE_VIDEO)
{
pStream = pFormatContext->streams[i];
stream_index = 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);
long request_timestamp = (long)(request_time * FFmpegInvoke.AV_TIME_BASE / (*pStream).time_base.num); //av_q2d(stream_time_base);
FFmpegInvoke.avformat_seek_file(pFormatContext, stream_index, long.MinValue, request_timestamp, long.MaxValue, 0);
//FFmpegInvoke.av_seek_frame(pFormatContext, stream_index, timestamp, 0);
int frameNumber = 0;
while (frameNumber < 1)
{
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))
{
form.SetImage(bitmap);
//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);
}