| 164 | |
| 165 | |
| 166 | bool Unpack::ReadTables20() |
| 167 | { |
| 168 | byte BitLength[BC20]; |
| 169 | byte Table[MC20*4]; |
| 170 | if (Inp.InAddr>ReadTop-25) |
| 171 | if (!UnpReadBuf()) |
| 172 | return false; |
| 173 | uint BitField=Inp.getbits(); |
| 174 | UnpAudioBlock=(BitField & 0x8000)!=0; |
| 175 | |
| 176 | if (!(BitField & 0x4000)) |
| 177 | memset(UnpOldTable20,0,sizeof(UnpOldTable20)); |
| 178 | Inp.addbits(2); |
| 179 | |
| 180 | uint TableSize; |
| 181 | if (UnpAudioBlock) |
| 182 | { |
| 183 | UnpChannels=((BitField>>12) & 3)+1; |
| 184 | if (UnpCurChannel>=UnpChannels) |
| 185 | UnpCurChannel=0; |
| 186 | Inp.addbits(2); |
| 187 | TableSize=MC20*UnpChannels; |
| 188 | } |
| 189 | else |
| 190 | TableSize=NC20+DC20+RC20; |
| 191 | |
| 192 | for (uint I=0;I<BC20;I++) |
| 193 | { |
| 194 | BitLength[I]=(byte)(Inp.getbits() >> 12); |
| 195 | Inp.addbits(4); |
| 196 | } |
| 197 | MakeDecodeTables(BitLength,&BlockTables.BD,BC20); |
| 198 | for (uint I=0;I<TableSize;) |
| 199 | { |
| 200 | if (Inp.InAddr>ReadTop-5) |
| 201 | if (!UnpReadBuf()) |
| 202 | return false; |
| 203 | uint Number=DecodeNumber(Inp,&BlockTables.BD); |
| 204 | if (Number<16) |
| 205 | { |
| 206 | Table[I]=(Number+UnpOldTable20[I]) & 0xf; |
| 207 | I++; |
| 208 | } |
| 209 | else |
| 210 | if (Number==16) |
| 211 | { |
| 212 | uint N=(Inp.getbits() >> 14)+3; |
| 213 | Inp.addbits(2); |
| 214 | if (I==0) |
| 215 | return false; // We cannot have "repeat previous" code at the first position. |
| 216 | else |
| 217 | while (N-- > 0 && I<TableSize) |
| 218 | { |
| 219 | Table[I]=Table[I-1]; |
| 220 | I++; |
| 221 | } |
| 222 | } |
| 223 | else |