/// <summary>
/// Initializes a new instance of the <see cref="SubtitleFrame" /> class.
/// </summary>
/// <param name="frame">The frame.</param>
/// <param name="component">The component.</param>
internal SubtitleFrame(AVSubtitle *frame, MediaComponent component)
: base(frame, component)
{
m_Pointer = (AVSubtitle *)InternalPointer;
// Extract timing information (pts for Subtitles is always in AV_TIME_BASE units)
var timeOffset = TimeSpan.FromTicks(frame->pts.ToTimeSpan(ffmpeg.AV_TIME_BASE).Ticks - component.Container.MediaStartTimeOffset.Ticks);
StartTime = TimeSpan.FromTicks(timeOffset.Ticks + ((long)frame->start_display_time).ToTimeSpan(StreamTimeBase).Ticks);
EndTime = TimeSpan.FromTicks(timeOffset.Ticks + ((long)frame->end_display_time).ToTimeSpan(StreamTimeBase).Ticks);
Duration = TimeSpan.FromTicks(EndTime.Ticks - StartTime.Ticks);
// Extract text strings
for (var i = 0; i < frame->num_rects; i++)
{
var rect = frame->rects[i];
if (rect->text != null)
{
Text.Add(Utils.PtrToStringUTF8(rect->text));
}
}
// Immediately release the frame as the struct was created in managed memory
// Accessing it later will eventually caused a memory access error.
Release();
}
/// <summary>
/// Initializes a new instance of the <see cref="VideoFrame" /> class.
/// </summary>
/// <param name="frame">The frame.</param>
/// <param name="component">The component.</param>
internal VideoFrame(AVFrame *frame, MediaComponent component)
: base(frame, component)
{
m_Pointer = (AVFrame *)InternalPointer;
// for vide frames, we always get the best effort timestamp as dts and pts might
// contain different times.
frame->pts = ffmpeg.av_frame_get_best_effort_timestamp(frame);
StartTime = frame->pts == Constants.AV_NOPTS ?
TimeSpan.FromTicks(component.Container.MediaStartTimeOffset.Ticks) :
TimeSpan.FromTicks(frame->pts.ToTimeSpan(StreamTimeBase).Ticks - component.Container.MediaStartTimeOffset.Ticks);
var repeatFactor = 1d + (0.5d * frame->repeat_pict);
var timeBase = ffmpeg.av_guess_frame_rate(component.Container.InputContext, component.Stream, frame);
Duration = repeatFactor.ToTimeSpan(new AVRational {
num = timeBase.den, den = timeBase.num
});
EndTime = TimeSpan.FromTicks(StartTime.Ticks + Duration.Ticks);
}
/// <summary>
/// Initializes a new instance of the <see cref="AudioFrame" /> class.
/// </summary>
/// <param name="frame">The frame.</param>
/// <param name="component">The component.</param>
internal AudioFrame(AVFrame *frame, MediaComponent component)
: base(frame, component)
{
m_Pointer = (AVFrame *)InternalPointer;
// Compute the timespans
//frame->pts = ffmpeg.av_frame_get_best_effort_timestamp(frame);
StartTime = frame->pts == Constants.AV_NOPTS ?
TimeSpan.FromTicks(component.Container.MediaStartTimeOffset.Ticks) :
TimeSpan.FromTicks(frame->pts.ToTimeSpan(StreamTimeBase).Ticks - component.Container.MediaStartTimeOffset.Ticks);
// Compute the audio frame duration
if (frame->pkt_duration != 0)
{
Duration = frame->pkt_duration.ToTimeSpan(StreamTimeBase);
}
else
{
Duration = TimeSpan.FromTicks((long)Math.Round(TimeSpan.TicksPerMillisecond * 1000d * frame->nb_samples / frame->sample_rate, 0));
}
EndTime = TimeSpan.FromTicks(StartTime.Ticks + Duration.Ticks);
}
/// <summary>
/// Initializes a new instance of the <see cref="MediaFrame" /> class.
/// </summary>
/// <param name="pointer">The pointer.</param>
/// <param name="component">The component.</param>
internal MediaFrame(void *pointer, MediaComponent component)
{
InternalPointer = pointer;
StreamTimeBase = component.Stream->time_base;
}
