public static float CalculateTimeScale(MovieMetadataBox moovBox, TrackBox trackBox)
{
MovieHeaderBox headerBox = moovBox.MovieHeaderBox;
ulong moovDuration = headerBox.Duration;
uint moovTimeScale = headerBox.TimeScale;
MediaHeaderBox mdhdBox = trackBox.MediaBox.MediaHeaderBox;
ulong mediaDuration = mdhdBox.Duration;
float mediaTimeScale = mdhdBox.TimeScale;
// Note that time scales may differ between moov and each media (because sampling rate can differ?)
moovDuration = moovDuration / moovTimeScale;
mediaDuration = (ulong)(mediaDuration / mediaTimeScale);
long diff = Math.Abs((long)moovDuration - (long)mediaDuration);
if ((diff * diff) > (long)((moovDuration * moovDuration) / 100)) // must be within 1%
{
throw new Exception("Media Box Header inconsistent with Track Header");
}
// scale to 10,000,000 ticks per second
mediaTimeScale /= TimeSpan.FromSeconds(1.0).Ticks;
if (mediaTimeScale == 0)
{
throw new Exception("MP4VideoTrack: media time scale is zero");
}
return(mediaTimeScale);
}
public MediaBox(IsochronousTrackInfo trackInfo)
: this()
{
ulong scaledDuration = (ulong)TimeArithmetic.ConvertToTimeScale(trackInfo.TimeScale, trackInfo.DurationIn100NanoSecs);
MediaHeaderBox = new MediaHeaderBox(this, scaledDuration, trackInfo.TimeScale);
this.Size += MediaHeaderBox.Size;
Codec codec = null;
if (trackInfo.GetType() == typeof(RawAudioTrackInfo))
{
RawAudioTrackInfo audioInfo = (RawAudioTrackInfo)trackInfo;
codec = new Codec(CodecTypes.Audio);
codec.PrivateCodecData = audioInfo.CodecPrivateData;
}
else if (trackInfo.GetType() == typeof(RawVideoTrackInfo))
{
RawVideoTrackInfo videoInfo = (RawVideoTrackInfo)trackInfo;
codec = new Codec(CodecTypes.Video);
codec.PrivateCodecData = videoInfo.CodecPrivateData;
}
HandlerReferenceBox = new HandlerReferenceBox(this, codec);
this.Size += HandlerReferenceBox.Size;
MediaInformationBox = new MediaInformationBox(this, trackInfo);
// MediaInformationBox.Size is indeterminate at this time; it is determined only during SampleTableBox.FinalizeBox
}
public override void Write(BoxWriter writer)
{
using (new SizeCalculator(this, writer))
{
base.Write(writer);
MediaHeaderBox.Write(writer);
HandlerReferenceBox.Write(writer);
MediaInformationBox.Write(writer);
}
}
public override string ToString()
{
StringBuilder xml = new StringBuilder();
xml.Append(base.ToString());
xml.Append(MediaHeaderBox.ToString());
xml.Append(HandlerReferenceBox.ToString());
xml.Append(MediaInformationBox.ToString());
xml.Append("</box>");
return(xml.ToString());
}
public override void Read(BoxReader reader)
{
using (new SizeChecker(this, reader)) {
base.Read(reader);
MediaHeaderBox = new MediaHeaderBox(this);
HandlerReferenceBox = new HandlerReferenceBox(this);
MediaInformationBox = new MediaInformationBox(this);
MediaHeaderBox.Read(reader);
HandlerReferenceBox.Read(reader);
MediaInformationBox.Read(reader);
}
}
public override void Read(BoxReader reader)
{
using (new SizeChecker(this, reader)) {
base.Read(reader);
MediaHeaderBox = new MediaHeaderBox(this);
HandlerReferenceBox = new HandlerReferenceBox(this);
MediaInformationBox = new MediaInformationBox(this);
MediaHeaderBox.Read(reader);
HandlerReferenceBox.Read(reader);
MediaInformationBox.Read(reader);
}
}
public MediaBox(IsochronousTrackInfo trackInfo)
: this()
{
ulong scaledDuration = (ulong)TimeArithmetic.ConvertToTimeScale(trackInfo.TimeScale, trackInfo.DurationIn100NanoSecs);
MediaHeaderBox = new MediaHeaderBox(this, scaledDuration, trackInfo.TimeScale);
this.Size += MediaHeaderBox.Size;
Codec codec = null;
if (trackInfo.GetType() == typeof(RawAudioTrackInfo))
{
RawAudioTrackInfo audioInfo = (RawAudioTrackInfo)trackInfo;
codec = new Codec(CodecTypes.Audio);
codec.PrivateCodecData = audioInfo.CodecPrivateData;
}
else if (trackInfo.GetType() == typeof(RawVideoTrackInfo))
{
RawVideoTrackInfo videoInfo = (RawVideoTrackInfo)trackInfo;
codec = new Codec(CodecTypes.Video);
codec.PrivateCodecData = videoInfo.CodecPrivateData;
}
HandlerReferenceBox = new HandlerReferenceBox(this, codec);
this.Size += HandlerReferenceBox.Size;
MediaInformationBox = new MediaInformationBox(this, trackInfo);
// MediaInformationBox.Size is indeterminate at this time; it is determined only during SampleTableBox.FinalizeBox
}