/// <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);
}
/// <inheritdoc />
public override bool MaterializeFrame(MediaFrame input, ref MediaBlock output, MediaBlock previousBlock)
{
if (output == null)
{
output = new SubtitleBlock();
}
if (input is SubtitleFrame == false || output is SubtitleBlock == false)
{
throw new ArgumentNullException($"{nameof(input)} and {nameof(output)} are either null or not of a compatible media type '{MediaType}'");
}
var source = (SubtitleFrame)input;
var target = (SubtitleBlock)output;
// Set the target data
target.EndTime = source.EndTime;
target.StartTime = source.StartTime;
target.Duration = source.Duration;
target.StreamIndex = input.StreamIndex;
// Process time offsets
if (Delay != TimeSpan.Zero)
{
target.StartTime = TimeSpan.FromTicks(target.StartTime.Ticks + Delay.Ticks);
target.EndTime = TimeSpan.FromTicks(target.EndTime.Ticks + Delay.Ticks);
target.Duration = TimeSpan.FromTicks(target.EndTime.Ticks - target.StartTime.Ticks);
}
target.OriginalText.Clear();
if (source.Text.Count > 0)
{
foreach (var t in source.Text)
{
target.OriginalText.Add(t);
}
}
target.OriginalTextType = source.TextType;
target.Text.Clear();
foreach (var text in source.Text)
{
if (string.IsNullOrWhiteSpace(text))
{
continue;
}
if (source.TextType == AVSubtitleType.SUBTITLE_ASS)
{
var strippedText = StripAssFormat(text);
if (string.IsNullOrWhiteSpace(strippedText) == false)
{
target.Text.Add(strippedText);
}
}
else
{
var strippedText = StripSrtFormat(text);
if (string.IsNullOrWhiteSpace(strippedText) == false)
{
target.Text.Add(strippedText);
}
}
}
// TODO: CompressedSize is just an estimate.
// It would be better if we counted chars in all text lines.
target.CompressedSize = source.CompressedSize;
return(true);
}
/// <inheritdoc />
public override bool MaterializeFrame(MediaFrame input, ref MediaBlock output, MediaBlock previousBlock)
{
if (output == null)
{
output = new VideoBlock();
}
if (input is VideoFrame == false || output is VideoBlock == false)
{
throw new ArgumentNullException($"{nameof(input)} and {nameof(output)} are either null or not of a compatible media type '{MediaType}'");
}
var source = (VideoFrame)input;
var target = (VideoBlock)output;
// Retrieve a suitable scaler or create it on the fly
var newScaler = ffmpeg.sws_getCachedContext(
Scaler,
source.Pointer->width,
source.Pointer->height,
NormalizePixelFormat(source.Pointer),
source.Pointer->width,
source.Pointer->height,
Constants.VideoPixelFormat,
ScalerFlags,
null,
null,
null);
// if it's the first time we set the scaler, simply assign it.
if (Scaler == null)
{
Scaler = newScaler;
RC.Current.Add(Scaler);
}
// Reassign to the new scaler and remove the reference to the existing one
// The get cached context function automatically frees the existing scaler.
if (Scaler != newScaler)
{
RC.Current.Remove(Scaler);
Scaler = newScaler;
}
// Perform scaling and save the data to our unmanaged buffer pointer
if (target.Allocate(source, Constants.VideoPixelFormat) &&
target.TryAcquireWriterLock(out var writeLock))
{
using (writeLock)
{
var targetStride = new[] { target.PictureBufferStride };
var targetScan = default(byte_ptrArray8);
targetScan[0] = (byte *)target.Buffer;
// The scaling is done here
var outputHeight = ffmpeg.sws_scale(
Scaler,
source.Pointer->data,
source.Pointer->linesize,
0,
source.Pointer->height,
targetScan,
targetStride);
if (outputHeight <= 0)
{
return(false);
}
}
}
else
{
return(false);
}
// After scaling, we need to copy and guess some of the block properties
// 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);
// Guess picture number and SMTPE
var frameRate = ffmpeg.av_guess_frame_rate(Container.InputContext, Stream, source.Pointer);
target.DisplayPictureNumber = Utilities.ComputePictureNumber(StartTime, target.StartTime, frameRate);
target.SmtpeTimeCode = Utilities.ComputeSmtpeTimeCode(target.DisplayPictureNumber, frameRate);
}
else
{
// We set the target properties directly from the source
target.StartTime = source.StartTime;
target.Duration = source.Duration;
target.EndTime = source.EndTime;
// Copy picture number and SMTPE
target.DisplayPictureNumber = source.DisplayPictureNumber;
target.SmtpeTimeCode = source.SmtpeTimeCode;
}
// Fill out other properties
target.IsHardwareFrame = source.IsHardwareFrame;
target.HardwareAcceleratorName = source.HardwareAcceleratorName;
target.CompressedSize = source.CompressedSize;
target.CodedPictureNumber = source.CodedPictureNumber;
target.StreamIndex = source.StreamIndex;
target.ClosedCaptions = source.ClosedCaptions.ToList();
// Update the stream info object if we get Closed Caption Data
if (StreamInfo.HasClosedCaptions == false && target.ClosedCaptions.Count > 0)
{
StreamInfo.HasClosedCaptions = true;
}
// Process the aspect ratio
var aspectRatio = ffmpeg.av_guess_sample_aspect_ratio(Container.InputContext, Stream, source.Pointer);
if (aspectRatio.num == 0 || aspectRatio.den == 0)
{
target.PixelAspectWidth = 1;
target.PixelAspectHeight = 1;
}
else
{
target.PixelAspectWidth = aspectRatio.num;
target.PixelAspectHeight = aspectRatio.den;
}
return(true);
}
