2 |
#define _VLC_CODES_H_ |
#define _VLC_CODES_H_ |
3 |
|
|
4 |
#include "../portab.h" |
#include "../portab.h" |
5 |
|
#include "mbcoding.h" |
6 |
|
|
7 |
#define VLC_ERROR (-1) |
#define VLC_ERROR (-1) |
8 |
|
#define ESCAPE 7167 |
9 |
|
|
10 |
typedef struct |
typedef struct |
11 |
{ |
{ |
13 |
int8_t len; |
int8_t len; |
14 |
} VLC; |
} VLC; |
15 |
|
|
16 |
|
static VLC *DCT3D[2]; |
17 |
|
|
18 |
|
|
19 |
/****************************************************************** |
/****************************************************************** |
20 |
* common tables between encoder/decoder * |
* common tables between encoder/decoder * |
636 |
coeff_inter_last1, |
coeff_inter_last1, |
637 |
}; |
}; |
638 |
|
|
639 |
static const VLC mcbpc_I[4] = { |
/* MCBPC Indexing by cbpc in first two bits, mode in last two. |
640 |
{1, 1}, {1, 3}, {2, 3}, {3, 3} |
CBPC as in table 4/H.263, MB type (mode): 3 = 01, 4 = 10. |
641 |
}; |
Example: cbpc = 01 and mode = 4 gives index = 0110 = 6. */ |
642 |
|
|
643 |
static const VLC mcbpc_P_intra[4] = { |
static VLC mcbpc_intra_tab[15] = { |
644 |
{3, 5}, {4, 8}, {3, 8}, {3, 7} |
{0x01, 9}, {0x01, 1}, {0x01, 4}, {0x00, 0}, |
645 |
}; |
{0x00, 0}, {0x01, 3}, {0x01, 6}, {0x00, 0}, |
646 |
|
{0x00, 0}, {0x02, 3}, {0x02, 6}, {0x00, 0}, |
647 |
static const VLC mcbpc_P_inter[4] = { |
{0x00, 0}, {0x03, 3}, {0x03, 6} |
648 |
{1, 1}, {3, 4}, {2, 4}, {5, 6} |
}; |
649 |
}; |
|
650 |
|
/* MCBPC inter. |
651 |
static const VLC mcbpc_P_inter4v[4] = { |
Addressing: 5 bit ccmmm (cc = CBPC, mmm = mode (1-4 binary)) */ |
652 |
{2, 3}, {5, 7}, {4, 7}, {5, 8} |
|
653 |
|
static VLC mcbpc_inter_tab[29] = { |
654 |
|
{1, 1}, {3, 3}, {2, 3}, {3, 5}, {4, 6}, {1, 9}, {0, 0}, {0, 0}, |
655 |
|
{3, 4}, {7, 7}, {5, 7}, {4, 8}, {4, 9}, {0, 0}, {0, 0}, {0, 0}, |
656 |
|
{2, 4}, {6, 7}, {4, 7}, {3, 8}, {3, 9}, {0, 0}, {0, 0}, {0, 0}, |
657 |
|
{5, 6}, {5, 9}, {5, 8}, {3, 7}, {2, 9} |
658 |
}; |
}; |
659 |
|
|
660 |
static const VLC cbpy_tab[16] = { |
static const VLC cbpy_tab[16] = { |
1227 |
{2, 2}, {2, 2}, {1, 2}, {1, 2}, |
{2, 2}, {2, 2}, {1, 2}, {1, 2}, |
1228 |
}; |
}; |
1229 |
|
|
1230 |
|
static __inline int get_coeff(Bitstream * bs, int *run, int *last, |
1231 |
|
int intra, int short_video_header) |
1232 |
|
{ |
1233 |
|
|
1234 |
|
uint32_t mode; |
1235 |
|
const VLC *tab; |
1236 |
|
int32_t level; |
1237 |
|
|
1238 |
|
if(short_video_header) // inter-VLCs will be used for both intra and inter blocks |
1239 |
|
intra = 0; |
1240 |
|
|
1241 |
|
tab = &DCT3D[intra][BitstreamShowBits(bs, 12)]; |
1242 |
|
|
1243 |
|
if(tab->code == -1) |
1244 |
|
goto error; |
1245 |
|
|
1246 |
|
BitstreamSkip(bs, tab->len); |
1247 |
|
|
1248 |
|
if(tab->code != ESCAPE) { |
1249 |
|
if(!intra) |
1250 |
|
{ |
1251 |
|
*run = (tab->code >> 4) & 255; |
1252 |
|
level = tab->code & 15; |
1253 |
|
*last = (tab->code >> 12) & 1; |
1254 |
|
} |
1255 |
|
else |
1256 |
|
{ |
1257 |
|
*run = (tab->code >> 8) & 255; |
1258 |
|
level = tab->code & 255; |
1259 |
|
*last = (tab->code >> 16) & 1; |
1260 |
|
} |
1261 |
|
return BitstreamGetBit(bs) ? -level : level; |
1262 |
|
} |
1263 |
|
|
1264 |
|
if(short_video_header) |
1265 |
|
{ |
1266 |
|
// escape mode 4 - H.263 type, only used if short_video_header = 1 |
1267 |
|
*last = BitstreamGetBit(bs); |
1268 |
|
*run = BitstreamGetBits(bs, 6); |
1269 |
|
level = BitstreamGetBits(bs, 8); |
1270 |
|
|
1271 |
|
if (level == 0 || level == 128) |
1272 |
|
DEBUG1("Illegal LEVEL for ESCAPE mode 4:", level); |
1273 |
|
|
1274 |
|
return (level >= 128 ? -(256 - level) : level); |
1275 |
|
} |
1276 |
|
|
1277 |
|
mode = BitstreamShowBits(bs, 2); |
1278 |
|
|
1279 |
|
if(mode < 3) { |
1280 |
|
BitstreamSkip(bs, (mode == 2) ? 2 : 1); |
1281 |
|
|
1282 |
|
tab = &DCT3D[intra][BitstreamShowBits(bs, 12)]; |
1283 |
|
if (tab->code == -1) |
1284 |
|
goto error; |
1285 |
|
|
1286 |
|
BitstreamSkip(bs, tab->len); |
1287 |
|
|
1288 |
|
if (!intra) { |
1289 |
|
*run = (tab->code >> 4) & 255; |
1290 |
|
level = tab->code & 15; |
1291 |
|
*last = (tab->code >> 12) & 1; |
1292 |
|
} |
1293 |
|
else |
1294 |
|
{ |
1295 |
|
*run = (tab->code >> 8) & 255; |
1296 |
|
level = tab->code & 255; |
1297 |
|
*last = (tab->code >> 16) & 1; |
1298 |
|
} |
1299 |
|
|
1300 |
|
if(mode < 2) // first escape mode, level is offset |
1301 |
|
level += max_level[*last + (!intra<<1)][*run]; // need to add back the max level |
1302 |
|
else if(mode == 2) // second escape mode, run is offset |
1303 |
|
*run += max_run[*last + (!intra<<1)][level] + 1; |
1304 |
|
|
1305 |
|
return BitstreamGetBit(bs) ? -level : level; |
1306 |
|
} |
1307 |
|
|
1308 |
|
// third escape mode - fixed length codes |
1309 |
|
BitstreamSkip(bs, 2); |
1310 |
|
*last = BitstreamGetBits(bs, 1); |
1311 |
|
*run = BitstreamGetBits(bs, 6); |
1312 |
|
BitstreamSkip(bs, 1); // marker |
1313 |
|
level = BitstreamGetBits(bs, 12); |
1314 |
|
BitstreamSkip(bs, 1); // marker |
1315 |
|
|
1316 |
|
return (level & 0x800) ? (level | (-1 ^ 0xfff)) : level; |
1317 |
|
|
1318 |
|
error: |
1319 |
|
*run = VLC_ERROR; |
1320 |
|
return 0; |
1321 |
|
|
1322 |
|
} |
1323 |
|
|
1324 |
#endif /* _VLC_CODES_H */ |
#endif /* _VLC_CODES_H */ |