/// <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> public abstract MediaBlock MaterializeFrame(MediaFrame input, ref MediaBlock output, List <MediaBlock> siblings);
/// <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 siblings to help guess additional frame parameters.</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 VideoBlock();
}
var source = input as VideoFrame;
var target = output as VideoBlock;
if (source == null || target == null)
{
throw new ArgumentNullException($"{nameof(input)} and {nameof(output)} are either null or not of a compatible media type '{MediaType}'");
}
// Retrieve a suitable scaler or create it on the fly
Scaler = ffmpeg.sws_getCachedContext(
Scaler,
source.Pointer->width,
source.Pointer->height,
NormalizePixelFormat(source.Pointer),
source.Pointer->width,
source.Pointer->height,
OutputPixelFormat,
ScalerFlags,
null,
null,
null);
RC.Current.Add(Scaler, $"311: {nameof(VideoComponent)}.{nameof(MaterializeFrame)}()");
// Perform scaling and save the data to our unmanaged buffer pointer
var targetBufferStride = ffmpeg.av_image_get_linesize(OutputPixelFormat, source.Pointer->width, 0);
var targetStride = new int[] { targetBufferStride };
var targetLength = ffmpeg.av_image_get_buffer_size(OutputPixelFormat, source.Pointer->width, source.Pointer->height, 1);
// Ensure proper allocation of the buffer
// If there is a size mismatch between the wanted buffer length and the existing one,
// then let's reallocate the buffer and set the new size (dispose of the existing one if any)
if (target.PictureBufferLength != targetLength)
{
if (target.PictureBuffer != IntPtr.Zero)
{
Marshal.FreeHGlobal(target.PictureBuffer);
}
target.PictureBufferLength = targetLength;
target.PictureBuffer = Marshal.AllocHGlobal(target.PictureBufferLength);
}
var targetScan = default(byte_ptrArray8);
targetScan[0] = (byte *)target.PictureBuffer;
// The scaling is done here
var outputHeight = ffmpeg.sws_scale(Scaler, source.Pointer->data, source.Pointer->linesize, 0, source.Pointer->height, targetScan, targetStride);
// 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.StreamIndex = input.StreamIndex;
target.SmtpeTimecode = source.SmtpeTimecode;
target.DisplayPictureNumber = source.DisplayPictureNumber;
target.CodedPictureNumber = source.DisplayPictureNumber;
target.BufferStride = targetStride[0];
target.PixelHeight = source.Pointer->height;
target.PixelWidth = source.Pointer->width;
var aspectRatio = source.Pointer->sample_aspect_ratio;
if (aspectRatio.num == 0 || aspectRatio.den == 0)
{
target.AspectWidth = 1;
target.AspectHeight = 1;
}
else
{
target.AspectWidth = aspectRatio.num;
target.AspectHeight = aspectRatio.den;
}
return(target);
}
/// <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);
}
