Ejemplo n.º 1
0
        /// <inheritdoc />
        public override bool MaterializeFrame(MediaFrame input, ref MediaBlock output, MediaBlock previousBlock)
        {
            if (output == null)
            {
                output = new AudioBlock();
            }
            if (input is AudioFrame == false || output is AudioBlock == false)
            {
                throw new ArgumentNullException($"{nameof(input)} and {nameof(output)} are either null or not of a compatible media type '{MediaType}'");
            }

            var source = (AudioFrame)input;
            var target = (AudioBlock)output;

            // Create the source and target audio specs. We might need to scale from
            // the source to the target
            var sourceSpec = FFAudioParams.CreateSource(source.Pointer);
            var targetSpec = FFAudioParams.CreateTarget(source.Pointer);

            // Initialize or update the audio scaler if required
            if (Scaler == null || LastSourceSpec == null || FFAudioParams.AreCompatible(LastSourceSpec, sourceSpec) == false)
            {
                Scaler = ffmpeg.swr_alloc_set_opts(
                    Scaler,
                    targetSpec.ChannelLayout,
                    targetSpec.Format,
                    targetSpec.SampleRate,
                    sourceSpec.ChannelLayout,
                    sourceSpec.Format,
                    sourceSpec.SampleRate,
                    0,
                    null);

                RC.Current.Add(Scaler);
                ffmpeg.swr_init(Scaler);
                LastSourceSpec = sourceSpec;
            }

            // Allocate the unmanaged output buffer and convert to stereo.
            int outputSamplesPerChannel;

            if (target.Allocate(targetSpec.BufferLength) &&
                target.TryAcquireWriterLock(out var writeLock))
            {
                using (writeLock)
                {
                    var outputBufferPtr = (byte *)target.Buffer;

                    // Execute the conversion (audio scaling). It will return the number of samples that were output
                    outputSamplesPerChannel = ffmpeg.swr_convert(
                        Scaler,
                        &outputBufferPtr,
                        targetSpec.SamplesPerChannel,
                        source.Pointer->extended_data,
                        source.Pointer->nb_samples);
                }
            }
            else
            {
                return(false);
            }

            // Compute the buffer length
            var outputBufferLength =
                ffmpeg.av_samples_get_buffer_size(null, targetSpec.ChannelCount, outputSamplesPerChannel, targetSpec.Format, 1);

            // Flag the block if we have to
            target.IsStartTimeGuessed = source.HasValidStartTime == false;

            // Try to fix the start time, duration and End time if we don't have valid data
            if (source.HasValidStartTime == false && previousBlock != null)
            {
                // Get timing information from the previous block
                target.StartTime = TimeSpan.FromTicks(previousBlock.EndTime.Ticks + 1);
                target.Duration  = source.Duration.Ticks > 0 ? source.Duration : previousBlock.Duration;
                target.EndTime   = TimeSpan.FromTicks(target.StartTime.Ticks + target.Duration.Ticks);
            }
            else
            {
                // We set the target properties directly from the source
                target.StartTime = source.StartTime;
                target.Duration  = source.Duration;
                target.EndTime   = source.EndTime;
            }

            target.CompressedSize      = source.CompressedSize;
            target.SamplesBufferLength = outputBufferLength;
            target.ChannelCount        = targetSpec.ChannelCount;

            target.SampleRate        = targetSpec.SampleRate;
            target.SamplesPerChannel = outputSamplesPerChannel;
            target.StreamIndex       = input.StreamIndex;

            return(true);
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Converts decoded, raw frame data in the frame source into a a usable frame. <br />
        /// The process includes performing picture, samples or text conversions
        /// so that the decoded source frame data is easily usable in multimedia applications
        /// </summary>
        /// <param name="input">The source frame to use as an input.</param>
        /// <param name="output">The target frame that will be updated with the source frame. If null is passed the frame will be instantiated.</param>
        /// <param name="siblings">The sibling blocks that may help guess some additional parameters for the input frame.</param>
        /// <returns>
        /// Return the updated output frame
        /// </returns>
        /// <exception cref="System.ArgumentNullException">input</exception>
        public override MediaBlock MaterializeFrame(MediaFrame input, ref MediaBlock output, List <MediaBlock> siblings)
        {
            if (output == null)
            {
                output = new AudioBlock();
            }
            var source = input as AudioFrame;
            var target = output as AudioBlock;

            if (source == null || target == null)
            {
                throw new ArgumentNullException($"{nameof(input)} and {nameof(output)} are either null or not of a compatible media type '{MediaType}'");
            }

            // Create the source and target ausio specs. We might need to scale from
            // the source to the target
            var sourceSpec = AudioParams.CreateSource(source.Pointer);
            var targetSpec = AudioParams.CreateTarget(source.Pointer);

            // Initialize or update the audio scaler if required
            if (Scaler == null || LastSourceSpec == null || AudioParams.AreCompatible(LastSourceSpec, sourceSpec) == false)
            {
                Scaler = ffmpeg.swr_alloc_set_opts(
                    Scaler,
                    targetSpec.ChannelLayout,
                    targetSpec.Format,
                    targetSpec.SampleRate,
                    sourceSpec.ChannelLayout,
                    sourceSpec.Format,
                    sourceSpec.SampleRate,
                    0,
                    null);

                RC.Current.Add(Scaler, $"109: {nameof(AudioComponent)}.{nameof(MaterializeFrame)}()");
                ffmpeg.swr_init(Scaler);
                LastSourceSpec = sourceSpec;
            }

            // Allocate the unmanaged output buffer
            if (target.AudioBufferLength != targetSpec.BufferLength)
            {
                if (target.AudioBuffer != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(target.AudioBuffer);
                }

                target.AudioBufferLength = targetSpec.BufferLength;
                target.AudioBuffer       = Marshal.AllocHGlobal(targetSpec.BufferLength);
            }

            var outputBufferPtr = (byte *)target.AudioBuffer;

            // Execute the conversion (audio scaling). It will return the number of samples that were output
            var outputSamplesPerChannel =
                ffmpeg.swr_convert(
                    Scaler,
                    &outputBufferPtr,
                    targetSpec.SamplesPerChannel,
                    source.Pointer->extended_data,
                    source.Pointer->nb_samples);

            // Compute the buffer length
            var outputBufferLength =
                ffmpeg.av_samples_get_buffer_size(null, targetSpec.ChannelCount, outputSamplesPerChannel, targetSpec.Format, 1);

            // Flag the block if we have to
            target.IsStartTimeGuessed = source.HasValidStartTime == false;

            // Try to fix the start time, duration and End time if we don't have valid data
            if (source.HasValidStartTime == false && siblings != null && siblings.Count > 0)
            {
                // Get timing information from the last sibling
                var lastSibling = siblings[siblings.Count - 1];

                // We set the target properties
                target.StartTime = lastSibling.EndTime;
                target.Duration  = source.Duration.Ticks > 0 ? source.Duration : lastSibling.Duration;
                target.EndTime   = TimeSpan.FromTicks(target.StartTime.Ticks + target.Duration.Ticks);
            }
            else
            {
                // We set the target properties directly from the source
                target.StartTime = source.StartTime;
                target.Duration  = source.Duration;
                target.EndTime   = source.EndTime;
            }

            target.BufferLength = outputBufferLength;
            target.ChannelCount = targetSpec.ChannelCount;

            target.SampleRate        = targetSpec.SampleRate;
            target.SamplesPerChannel = outputSamplesPerChannel;
            target.StreamIndex       = input.StreamIndex;

            return(target);
        }
Ejemplo n.º 3
0
        /// <summary>
        /// Converts decoded, raw frame data in the frame source into a a usable frame. <br />
        /// The process includes performing picture, samples or text conversions
        /// so that the decoded source frame data is easily usable in multimedia applications
        /// </summary>
        /// <param name="input">The source frame to use as an input.</param>
        /// <param name="output">The target frame that will be updated with the source frame. If null is passed the frame will be instantiated.</param>
        /// <returns>
        /// Return the updated output frame
        /// </returns>
        /// <exception cref="System.ArgumentNullException">input</exception>
        internal override MediaBlock MaterializeFrame(MediaFrame input, ref MediaBlock output)
        {
            if (output == null)
            {
                output = new AudioBlock();
            }
            var source = input as AudioFrame;
            var target = output as AudioBlock;

            if (source == null || target == null)
            {
                throw new ArgumentNullException($"{nameof(input)} and {nameof(output)} are either null or not of a compatible media type '{MediaType}'");
            }

            // Create the source and target ausio specs. We might need to scale from
            // the source to the target
            var sourceSpec = AudioParams.CreateSource(source.Pointer);
            var targetSpec = AudioParams.CreateTarget(source.Pointer);

            // Initialize or update the audio scaler if required
            if (Scaler == null || LastSourceSpec == null || AudioParams.AreCompatible(LastSourceSpec, sourceSpec) == false)
            {
                Scaler = ffmpeg.swr_alloc_set_opts(Scaler, targetSpec.ChannelLayout, targetSpec.Format, targetSpec.SampleRate,
                                                   sourceSpec.ChannelLayout, sourceSpec.Format, sourceSpec.SampleRate, 0, null);

                RC.Current.Add(Scaler, $"109: {nameof(AudioComponent)}.{nameof(MaterializeFrame)}()");
                ffmpeg.swr_init(Scaler);
                LastSourceSpec = sourceSpec;
            }

            // Allocate the unmanaged output buffer
            if (target.AudioBufferLength != targetSpec.BufferLength)
            {
                if (target.AudioBuffer != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(target.AudioBuffer);
                }

                target.AudioBufferLength = targetSpec.BufferLength;
                target.AudioBuffer       = Marshal.AllocHGlobal(targetSpec.BufferLength);
            }

            var outputBufferPtr = (byte *)target.AudioBuffer;

            // Execute the conversion (audio scaling). It will return the number of samples that were output
            var outputSamplesPerChannel =
                ffmpeg.swr_convert(Scaler, &outputBufferPtr, targetSpec.SamplesPerChannel,
                                   source.Pointer->extended_data, source.Pointer->nb_samples);

            // Compute the buffer length
            var outputBufferLength =
                ffmpeg.av_samples_get_buffer_size(null, targetSpec.ChannelCount, outputSamplesPerChannel, targetSpec.Format, 1);

            // set the target properties
            target.StartTime         = source.StartTime;
            target.EndTime           = source.EndTime;
            target.BufferLength      = outputBufferLength;
            target.ChannelCount      = targetSpec.ChannelCount;
            target.Duration          = source.Duration;
            target.SampleRate        = targetSpec.SampleRate;
            target.SamplesPerChannel = outputSamplesPerChannel;

            return(target);
        }