/// <inheritdoc />
        protected override MediaFrame CreateFrameSource(IntPtr framePointer)
        {
            // Validate the audio frame
            var frame = (AVFrame *)framePointer;

            if (framePointer == IntPtr.Zero || frame->channels <= 0 || frame->nb_samples <= 0 || frame->sample_rate <= 0)
            {
                return(null);
            }

            if (string.IsNullOrWhiteSpace(FilterString) == false)
            {
                InitializeFilterGraph(frame);
            }

            AVFrame *outputFrame;

            // Filter Graph can be changed by issuing a ChangeMedia command
            if (FilterGraph != null)
            {
                // Allocate the output frame
                outputFrame = MediaFrame.CloneAVFrame(frame);

                var result = ffmpeg.av_buffersrc_add_frame(SourceFilter, outputFrame);
                while (result >= 0)
                {
                    result = ffmpeg.av_buffersink_get_frame_flags(SinkFilter, outputFrame, 0);
                }

                if (outputFrame->nb_samples <= 0)
                {
                    // If we don't have a valid output frame simply release it and
                    // return the original input frame
                    MediaFrame.ReleaseAVFrame(outputFrame);
                    outputFrame = frame;
                }
                else
                {
                    // the output frame is the new valid frame (output frame).
                    // theretofore, we need to release the original
                    MediaFrame.ReleaseAVFrame(frame);
                }
            }
            else
            {
                outputFrame = frame;
            }

            // Check if the output frame is valid
            if (outputFrame->nb_samples <= 0)
            {
                return(null);
            }

            var frameHolder = new AudioFrame(outputFrame, this);

            return(frameHolder);
        }
Beispiel #2
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        /// <inheritdoc />
        protected override MediaFrame CreateFrameSource(IntPtr framePointer)
        {
            // Validate the video frame
            var frame = (AVFrame *)framePointer;

            if (framePointer == IntPtr.Zero || frame->width <= 0 || frame->height <= 0)
            {
                return(null);
            }

            // Move the frame from hardware (GPU) memory to RAM (CPU)
            if (HardwareAccelerator != null)
            {
                frame = HardwareAccelerator.ExchangeFrame(CodecContext, frame, out var isHardwareFrame);
                IsUsingHardwareDecoding = isHardwareFrame;
            }

            // Init the filter graph for the frame
            InitializeFilterGraph(frame);

            AVFrame *outputFrame;

            // Changes in the filter graph can be applied by calling the ChangeMedia command
            if (FilterGraph != null)
            {
                // Allocate the output frame
                outputFrame = MediaFrame.CloneAVFrame(frame);

                var result = ffmpeg.av_buffersrc_add_frame(SourceFilter, outputFrame);
                while (result >= 0)
                {
                    result = ffmpeg.av_buffersink_get_frame_flags(SinkFilter, outputFrame, 0);
                }

                if (outputFrame->width <= 0 || outputFrame->height <= 0)
                {
                    // If we don't have a valid output frame simply release it and
                    // return the original input frame
                    MediaFrame.ReleaseAVFrame(outputFrame);
                    outputFrame = frame;
                }
                else
                {
                    // the output frame is the new valid frame (output frame).
                    // therefore, we need to release the original
                    MediaFrame.ReleaseAVFrame(frame);
                }
            }
            else
            {
                outputFrame = frame;
            }

            // Check if the output frame is valid
            if (outputFrame->width <= 0 || outputFrame->height <= 0)
            {
                return(null);
            }

            // Create the frame holder object and return it.
            return(new VideoFrame(outputFrame, this));
        }