public static void readExtension(MemoryStream bb, SequenceHeader sh)
{
m_hasExtensions = true;
BitReader inb = new BitReader(bb);
int extType = inb.readNBit(4);
switch (extType)
{
case Sequence_Extension:
sh.sequenceExtension = SequenceExtension.read(inb);
break;
case Sequence_Scalable_Extension:
sh.sequenceScalableExtension = SequenceScalableExtension.read(inb);
break;
case Sequence_Display_Extension:
sh.sequenceDisplayExtension = SequenceDisplayExtension.read(inb);
break;
default:
throw new Exception("Unsupported extension: " + extType);
}
}
public static SequenceScalableExtension read(BitReader inb)
{
SequenceScalableExtension sse = new SequenceScalableExtension();
sse.scalable_mode = inb.readNBit(2);
sse.layer_id = inb.readNBit(4);
if (sse.scalable_mode == SPATIAL_SCALABILITY)
{
sse.lower_layer_prediction_horizontal_size = inb.readNBit(14);
inb.read1Bit();
sse.lower_layer_prediction_vertical_size = inb.readNBit(14);
sse.horizontal_subsampling_factor_m = inb.readNBit(5);
sse.horizontal_subsampling_factor_n = inb.readNBit(5);
sse.vertical_subsampling_factor_m = inb.readNBit(5);
sse.vertical_subsampling_factor_n = inb.readNBit(5);
}
if (sse.scalable_mode == TEMPORAL_SCALABILITY)
{
sse.picture_mux_enable = inb.read1Bit();
if (sse.picture_mux_enable != 0)
{
sse.mux_to_progressive_sequence = inb.read1Bit();
}
sse.picture_mux_order = inb.readNBit(3);
sse.picture_mux_factor = inb.readNBit(3);
}
return(sse);
}
public static MBType[] mbTypeVal(int picture_coding_type, SequenceScalableExtension sse)
{
if (sse != null && sse.scalable_mode == SequenceScalableExtension.SNR_SCALABILITY)
{
return(mbTypeValSNR);
}
else if (sse != null && sse.scalable_mode == SequenceScalableExtension.SPATIAL_SCALABILITY)
{
return(picture_coding_type == PictureHeader.IntraCoded ? mbTypeValISpat
: (picture_coding_type == PictureHeader.PredictiveCoded ? mbTypeValPSpat : mbTypeValBSpat));
}
else
{
return(picture_coding_type == PictureHeader.IntraCoded ? mbTypeValI
: (picture_coding_type == PictureHeader.PredictiveCoded ? mbTypeValP : mbTypeValB));
}
}
public static VLC vlcMBType(int picture_coding_type, SequenceScalableExtension sse)
{
if (sse != null && sse.scalable_mode == SequenceScalableExtension.SNR_SCALABILITY)
{
return(vlcMBTypeSNR);
}
else if (sse != null && sse.scalable_mode == SequenceScalableExtension.SPATIAL_SCALABILITY)
{
return(picture_coding_type == PictureHeader.IntraCoded ? vlcMBTypeISpat
: (picture_coding_type == PictureHeader.PredictiveCoded ? vlcMBTypePSpat : vlcMBTypeBSpat));
}
else
{
return(picture_coding_type == PictureHeader.IntraCoded ? vlcMBTypeI
: (picture_coding_type == PictureHeader.PredictiveCoded ? vlcMBTypeP : vlcMBTypeB));
}
}
public void copyExtensions(SequenceHeader sh)
{
sequenceExtension = sh.sequenceExtension;
sequenceScalableExtension = sh.sequenceScalableExtension;
sequenceDisplayExtension = sh.sequenceDisplayExtension;
}
