C# IMediaSample.SetSyncPoint方法代码示例

        public static void CopySample(IMediaSample src, IMediaSample dest, bool copySamples)
        {
            var sourceSize = src.GetActualDataLength();

            if (copySamples)
            {
                IntPtr sourceBuffer;
                src.GetPointer(out sourceBuffer);

                IntPtr destBuffer;
                dest.GetPointer(out destBuffer);

                CopyMemory(destBuffer, sourceBuffer, sourceSize);
            }

            // Copy the sample times
            long start, end;

            if (src.GetTime(out start, out end) == S_OK)
            {
                dest.SetTime(start, end);
            }

            if (src.GetMediaTime(out start, out end) == S_OK)
            {
                dest.SetMediaTime(start, end);
            }

            // Copy the media type
            AMMediaType mediaType;
            src.GetMediaType(out mediaType);
            dest.SetMediaType(mediaType);
            DsUtils.FreeAMMediaType(mediaType);

            dest.SetSyncPoint(src.IsSyncPoint() == S_OK);
            dest.SetPreroll(src.IsPreroll() == S_OK);
            dest.SetDiscontinuity(src.IsDiscontinuity() == S_OK);

            // Copy the actual data length
            dest.SetActualDataLength(sourceSize);
        }

        /// <summary>
        /// Called by the GenericSampleSourceFilter.  This routine populates the MediaSample.
        /// </summary>
        /// <param name="pSample">Pointer to a sample</param>
        /// <returns>0 = success, 1 = end of stream, negative values for errors</returns>
        public virtual int SampleCallback(IMediaSample pSample)
        {
            int hr;
            IntPtr pData;

            try
            {
                // Get the buffer into which we will copy the data
                hr = pSample.GetPointer(out pData);
                if (hr >= 0)
                {
                    // Set TRUE on every sample for uncompressed frames
                    hr = pSample.SetSyncPoint(true);
                    if (hr >= 0)
                    {
                        // Find out the amount of space in the buffer
                        int cbData = pSample.GetSize();

                        hr = SetTimeStamps(pSample);
                        if (hr >= 0)
                        {
                            int iRead;

                            // Get copy the data into the sample
                            hr = GetImage(m_iFrameNumber, pData, cbData, out iRead);
                            if (hr == 0) // 1 == End of stream
                            {
                                pSample.SetActualDataLength(iRead);

                                // increment the frame number for next time
                                m_iFrameNumber++;
                            }
                        }
                    }
                }
            }
            finally
            {
                // Release our pointer the the media sample.  THIS IS ESSENTIAL!  If
                // you don't do this, the graph will stop after about 2 samples.
                Marshal.ReleaseComObject(pSample);
            }

            return hr;
        }

        /// <summary>
        /// Calculate and populate the timestamps
        /// </summary>
        /// <param name="pSample">The IMediaSample to set the timestamps on</param>
        /// <returns>HRESULT</returns>
        public override int SetTimeStamps(IMediaSample pSample)
        {
            // Time per frame
            int tpf = (UNIT / m_Fps);

            DsLong rtStart = new DsLong(m_rtSampleTime);
            m_rtSampleTime += tpf;

            DsLong rtStop = new DsLong(m_rtSampleTime);

            // Set the times into the sample
            int hr = pSample.SetTime(rtStart, rtStop);

            // Set TRUE on every sample for uncompressed frames
            if (hr >= 0)
            {
                hr = pSample.SetSyncPoint(true);
            }

            return hr;
        }

        /// <summary>
        /// This routine populates the MediaSample.
        /// </summary>
        /// <param name="pSample">Pointer to a sample</param>
        /// <returns>0 = success, 1 = end of stream, negative values for errors</returns>
        public int MediaSampleCB(IMediaSample pSample)
        {
            int hr;

            try
            {
                IntPtr pData;

                hr = pSample.GetPointer(out pData);
                if (hr >= 0)
                {
                    hr = pSample.SetSyncPoint(true);
                    if (hr >= 0)
                    {
                        var len = Source.Read(pData, Constants.DShowNumberOfPacketsTS);
                        if (len != 0)
                        {
                            hr = 0;
                            pSample.SetActualDataLength(len);
                        }
                        else
                        {
                            //hr = 1;
                            hr = 0;
                        }
                    }
                }
            }
            catch(Exception ex)
            {
                Log.ErrorException("Error in Sample handler.", ex);
                hr = -1;
            }
            finally
            {
                Marshal.ReleaseComObject(pSample);
            }

            return hr;
        }