/** Picture:
* @param b payload buffer
* @param d decoder of the picture
*
* The b buffer should only point to the payload data section of
* the picture (not the header). The only methods that would ever need
* to be called are parse(), decode(), and getImage(). However,
* one should check wether the error variable is set before and after
* calling a method. One should not call them in any other order than that
* just specified. Each can be called without arguments and should not be
* called twice. */
public Picture(Buffer b, Decoder d)
{
num = b.GetInt(13);
code = b.GetByte(4);
buf = b;
dec = d;
par = new Parameters(code);
coeffs = new SubBand[3][];
coeffs[0] = new SubBand[19];
coeffs[1] = new SubBand[19];
coeffs[2] = new SubBand[19];
motion_buffers = new Buffer[9];
status = Decoder.Status.NULL;
}
/** synchronized decoding
*
* Decodes the picture. */
public void Decode()
{
lock (obj)
{
if (status != Decoder.Status.OK)
return;
status = Decoder.Status.WAIT;
if (!zero_residual)
{
InitializeIwtFrames();
DecodeWaveletTransform();
}
if (!par.is_intra)
{
InitializeMCFrames();
DecodeMotionCompensate();
if (zero_residual)
iwt_frame = mc_frame;
else for (int i = 0; i < 3; i++)
mc_frame[i].AddTo(iwt_frame[i]);
}
if (par.is_ref)
{
if (retire != 0)
dec.refs.Remove(retire + num);
dec.refs.Add(num, iwt_frame);
}
CreateImage();
status = Decoder.Status.DONE;
}
}
public void Parse()
{
lock(obj)
{
if(status != Decoder.Status.NULL)
return;
status = Decoder.Status.WAIT;
try {
Unpack u = new Unpack(buf);
u.Skip(136); /* 17 * 8 */
ParseHeader(u);
par.CalculateIwtSizes(dec.format);
if(!par.is_intra) {
u.Align();
ParsePredictionParameters(u);
par.CalculateMCSizes();
u.Align();
ParseBlockData(u);
}
u.Align();
if(!par.is_intra) {
zero_residual = u.DecodeBool();
}
if(!zero_residual) {
ParseTransformParameters(u);
u.Align();
if(par.is_lowdelay) {
ParseLowDelayTransformData(u);
} else {
ParseTransformData(u);
}
}
status = Decoder.Status.OK;
} catch(Exception e) {
error = e;
status = Decoder.Status.ERROR;
}
buf = null;
}
}
