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truemotion1.c
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1 /*
2  * Duck TrueMotion 1.0 Decoder
3  * Copyright (C) 2003 Alex Beregszaszi & Mike Melanson
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Duck TrueMotion v1 Video Decoder by
25  * Alex Beregszaszi and
26  * Mike Melanson (melanson@pcisys.net)
27  *
28  * The TrueMotion v1 decoder presently only decodes 16-bit TM1 data and
29  * outputs RGB555 (or RGB565) data. 24-bit TM1 data is not supported yet.
30  */
31 
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 
36 #include "avcodec.h"
37 #include "internal.h"
38 #include "libavutil/imgutils.h"
39 #include "libavutil/internal.h"
40 #include "libavutil/intreadwrite.h"
41 #include "libavutil/mem.h"
42 
43 #include "truemotion1data.h"
44 
45 typedef struct TrueMotion1Context {
46  AVCodecContext *avctx;
47  AVFrame *frame;
48 
49  const uint8_t *buf;
50  int size;
51 
52  const uint8_t *mb_change_bits;
53  int mb_change_bits_row_size;
54  const uint8_t *index_stream;
55  int index_stream_size;
56 
57  int flags;
58  int x, y, w, h;
59 
60  uint32_t y_predictor_table[1024];
61  uint32_t c_predictor_table[1024];
62  uint32_t fat_y_predictor_table[1024];
63  uint32_t fat_c_predictor_table[1024];
64 
65  int compression;
66  int block_type;
67  int block_width;
68  int block_height;
69 
70  int16_t ydt[8];
71  int16_t cdt[8];
72  int16_t fat_ydt[8];
73  int16_t fat_cdt[8];
74 
75  int last_deltaset, last_vectable;
76 
77  unsigned int *vert_pred;
78  int vert_pred_size;
79 
80 } TrueMotion1Context;
81 
82 #define FLAG_SPRITE 32
83 #define FLAG_KEYFRAME 16
84 #define FLAG_INTERFRAME 8
85 #define FLAG_INTERPOLATED 4
86 
87 struct frame_header {
88  uint8_t header_size;
89  uint8_t compression;
90  uint8_t deltaset;
91  uint8_t vectable;
92  uint16_t ysize;
93  uint16_t xsize;
94  uint16_t checksum;
95  uint8_t version;
96  uint8_t header_type;
97  uint8_t flags;
98  uint8_t control;
99  uint16_t xoffset;
100  uint16_t yoffset;
101  uint16_t width;
102  uint16_t height;
103 };
104 
105 #define ALGO_NOP 0
106 #define ALGO_RGB16V 1
107 #define ALGO_RGB16H 2
108 #define ALGO_RGB24H 3
109 
110 /* these are the various block sizes that can occupy a 4x4 block */
111 #define BLOCK_2x2 0
112 #define BLOCK_2x4 1
113 #define BLOCK_4x2 2
114 #define BLOCK_4x4 3
115 
116 typedef struct comp_types {
117  int algorithm;
118  int block_width; // vres
119  int block_height; // hres
120  int block_type;
121 } comp_types;
122 
123 /* { valid for metatype }, algorithm, num of deltas, vert res, horiz res */
124 static const comp_types compression_types[17] = {
125  { ALGO_NOP, 0, 0, 0 },
126 
127  { ALGO_RGB16V, 4, 4, BLOCK_4x4 },
128  { ALGO_RGB16H, 4, 4, BLOCK_4x4 },
129  { ALGO_RGB16V, 4, 2, BLOCK_4x2 },
130  { ALGO_RGB16H, 4, 2, BLOCK_4x2 },
131 
132  { ALGO_RGB16V, 2, 4, BLOCK_2x4 },
133  { ALGO_RGB16H, 2, 4, BLOCK_2x4 },
134  { ALGO_RGB16V, 2, 2, BLOCK_2x2 },
135  { ALGO_RGB16H, 2, 2, BLOCK_2x2 },
136 
137  { ALGO_NOP, 4, 4, BLOCK_4x4 },
138  { ALGO_RGB24H, 4, 4, BLOCK_4x4 },
139  { ALGO_NOP, 4, 2, BLOCK_4x2 },
140  { ALGO_RGB24H, 4, 2, BLOCK_4x2 },
141 
142  { ALGO_NOP, 2, 4, BLOCK_2x4 },
143  { ALGO_RGB24H, 2, 4, BLOCK_2x4 },
144  { ALGO_NOP, 2, 2, BLOCK_2x2 },
145  { ALGO_RGB24H, 2, 2, BLOCK_2x2 }
146 };
147 
148 static void select_delta_tables(TrueMotion1Context *s, int delta_table_index)
149 {
150  int i;
151 
152  if (delta_table_index > 3)
153  return;
154 
155  memcpy(s->ydt, ydts[delta_table_index], 8 * sizeof(int16_t));
156  memcpy(s->cdt, cdts[delta_table_index], 8 * sizeof(int16_t));
157  memcpy(s->fat_ydt, fat_ydts[delta_table_index], 8 * sizeof(int16_t));
158  memcpy(s->fat_cdt, fat_cdts[delta_table_index], 8 * sizeof(int16_t));
159 
160  /* Y skinny deltas need to be halved for some reason; maybe the
161  * skinny Y deltas should be modified */
162  for (i = 0; i < 8; i++)
163  {
164  /* drop the lsb before dividing by 2-- net effect: round down
165  * when dividing a negative number (e.g., -3/2 = -2, not -1) */
166  s->ydt[i] &= 0xFFFE;
167  s->ydt[i] /= 2;
168  }
169 }
170 
171 #if HAVE_BIGENDIAN
172 static int make_ydt15_entry(int p2, int p1, int16_t *ydt)
173 #else
174 static int make_ydt15_entry(int p1, int p2, int16_t *ydt)
175 #endif
176 {
177  int lo, hi;
178 
179  lo = ydt[p1];
180  lo += (lo << 5) + (lo << 10);
181  hi = ydt[p2];
182  hi += (hi << 5) + (hi << 10);
183  return (lo + (hi << 16)) << 1;
184 }
185 
186 static int make_cdt15_entry(int p1, int p2, int16_t *cdt)
187 {
188  int r, b, lo;
189 
190  b = cdt[p2];
191  r = cdt[p1] << 10;
192  lo = b + r;
193  return (lo + (lo << 16)) << 1;
194 }
195 
196 #if HAVE_BIGENDIAN
197 static int make_ydt16_entry(int p2, int p1, int16_t *ydt)
198 #else
199 static int make_ydt16_entry(int p1, int p2, int16_t *ydt)
200 #endif
201 {
202  int lo, hi;
203 
204  lo = ydt[p1];
205  lo += (lo << 6) + (lo << 11);
206  hi = ydt[p2];
207  hi += (hi << 6) + (hi << 11);
208  return (lo + (hi << 16)) << 1;
209 }
210 
211 static int make_cdt16_entry(int p1, int p2, int16_t *cdt)
212 {
213  int r, b, lo;
214 
215  b = cdt[p2];
216  r = cdt[p1] << 11;
217  lo = b + r;
218  return (lo + (lo << 16)) << 1;
219 }
220 
221 static int make_ydt24_entry(int p1, int p2, int16_t *ydt)
222 {
223  int lo, hi;
224 
225  lo = ydt[p1];
226  hi = ydt[p2];
227  return (lo + (hi << 8) + (hi << 16)) << 1;
228 }
229 
230 static int make_cdt24_entry(int p1, int p2, int16_t *cdt)
231 {
232  int r, b;
233 
234  b = cdt[p2];
235  r = cdt[p1]<<16;
236  return (b+r) << 1;
237 }
238 
239 static void gen_vector_table15(TrueMotion1Context *s, const uint8_t *sel_vector_table)
240 {
241  int len, i, j;
242  unsigned char delta_pair;
243 
244  for (i = 0; i < 1024; i += 4)
245  {
246  len = *sel_vector_table++ / 2;
247  for (j = 0; j < len; j++)
248  {
249  delta_pair = *sel_vector_table++;
250  s->y_predictor_table[i+j] = 0xfffffffe &
251  make_ydt15_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
252  s->c_predictor_table[i+j] = 0xfffffffe &
253  make_cdt15_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
254  }
255  s->y_predictor_table[i+(j-1)] |= 1;
256  s->c_predictor_table[i+(j-1)] |= 1;
257  }
258 }
259 
260 static void gen_vector_table16(TrueMotion1Context *s, const uint8_t *sel_vector_table)
261 {
262  int len, i, j;
263  unsigned char delta_pair;
264 
265  for (i = 0; i < 1024; i += 4)
266  {
267  len = *sel_vector_table++ / 2;
268  for (j = 0; j < len; j++)
269  {
270  delta_pair = *sel_vector_table++;
271  s->y_predictor_table[i+j] = 0xfffffffe &
272  make_ydt16_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
273  s->c_predictor_table[i+j] = 0xfffffffe &
274  make_cdt16_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
275  }
276  s->y_predictor_table[i+(j-1)] |= 1;
277  s->c_predictor_table[i+(j-1)] |= 1;
278  }
279 }
280 
281 static void gen_vector_table24(TrueMotion1Context *s, const uint8_t *sel_vector_table)
282 {
283  int len, i, j;
284  unsigned char delta_pair;
285 
286  for (i = 0; i < 1024; i += 4)
287  {
288  len = *sel_vector_table++ / 2;
289  for (j = 0; j < len; j++)
290  {
291  delta_pair = *sel_vector_table++;
292  s->y_predictor_table[i+j] = 0xfffffffe &
293  make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
294  s->c_predictor_table[i+j] = 0xfffffffe &
295  make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
296  s->fat_y_predictor_table[i+j] = 0xfffffffe &
297  make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_ydt);
298  s->fat_c_predictor_table[i+j] = 0xfffffffe &
299  make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_cdt);
300  }
301  s->y_predictor_table[i+(j-1)] |= 1;
302  s->c_predictor_table[i+(j-1)] |= 1;
303  s->fat_y_predictor_table[i+(j-1)] |= 1;
304  s->fat_c_predictor_table[i+(j-1)] |= 1;
305  }
306 }
307 
308 /* Returns the number of bytes consumed from the bytestream. Returns -1 if
309  * there was an error while decoding the header */
310 static int truemotion1_decode_header(TrueMotion1Context *s)
311 {
312  int i, ret;
313  int width_shift = 0;
314  int new_pix_fmt;
315  struct frame_header header;
316  uint8_t header_buffer[128] = { 0 }; /* logical maximum size of the header */
317  const uint8_t *sel_vector_table;
318 
319  header.header_size = ((s->buf[0] >> 5) | (s->buf[0] << 3)) & 0x7f;
320  if (s->buf[0] < 0x10)
321  {
322  av_log(s->avctx, AV_LOG_ERROR, "invalid header size (%d)\n", s->buf[0]);
323  return AVERROR_INVALIDDATA;
324  }
325 
326  if (header.header_size + 1 > s->size) {
327  av_log(s->avctx, AV_LOG_ERROR, "Input packet too small.\n");
328  return AVERROR_INVALIDDATA;
329  }
330 
331  /* unscramble the header bytes with a XOR operation */
332  for (i = 1; i < header.header_size; i++)
333  header_buffer[i - 1] = s->buf[i] ^ s->buf[i + 1];
334 
335  header.compression = header_buffer[0];
336  header.deltaset = header_buffer[1];
337  header.vectable = header_buffer[2];
338  header.ysize = AV_RL16(&header_buffer[3]);
339  header.xsize = AV_RL16(&header_buffer[5]);
340  header.checksum = AV_RL16(&header_buffer[7]);
341  header.version = header_buffer[9];
342  header.header_type = header_buffer[10];
343  header.flags = header_buffer[11];
344  header.control = header_buffer[12];
345 
346  /* Version 2 */
347  if (header.version >= 2)
348  {
349  if (header.header_type > 3)
350  {
351  av_log(s->avctx, AV_LOG_ERROR, "invalid header type (%d)\n", header.header_type);
352  return AVERROR_INVALIDDATA;
353  } else if ((header.header_type == 2) || (header.header_type == 3)) {
354  s->flags = header.flags;
355  if (!(s->flags & FLAG_INTERFRAME))
356  s->flags |= FLAG_KEYFRAME;
357  } else
358  s->flags = FLAG_KEYFRAME;
359  } else /* Version 1 */
360  s->flags = FLAG_KEYFRAME;
361 
362  if (s->flags & FLAG_SPRITE) {
363  avpriv_request_sample(s->avctx, "Frame with sprite");
364  /* FIXME header.width, height, xoffset and yoffset aren't initialized */
365  return AVERROR_PATCHWELCOME;
366  } else {
367  s->w = header.xsize;
368  s->h = header.ysize;
369  if (header.header_type < 2) {
370  if ((s->w < 213) && (s->h >= 176))
371  {
372  s->flags |= FLAG_INTERPOLATED;
373  avpriv_request_sample(s->avctx, "Interpolated frame");
374  }
375  }
376  }
377 
378  if (header.compression >= 17) {
379  av_log(s->avctx, AV_LOG_ERROR, "invalid compression type (%d)\n", header.compression);
380  return AVERROR_INVALIDDATA;
381  }
382 
383  if ((header.deltaset != s->last_deltaset) ||
384  (header.vectable != s->last_vectable))
385  select_delta_tables(s, header.deltaset);
386 
387  if ((header.compression & 1) && header.header_type)
388  sel_vector_table = pc_tbl2;
389  else {
390  if (header.vectable > 0 && header.vectable < 4)
391  sel_vector_table = tables[header.vectable - 1];
392  else {
393  av_log(s->avctx, AV_LOG_ERROR, "invalid vector table id (%d)\n", header.vectable);
394  return AVERROR_INVALIDDATA;
395  }
396  }
397 
398  if (compression_types[header.compression].algorithm == ALGO_RGB24H) {
399  new_pix_fmt = AV_PIX_FMT_RGB32;
400  width_shift = 1;
401  } else
402  new_pix_fmt = AV_PIX_FMT_RGB555; // RGB565 is supported as well
403 
404  s->w >>= width_shift;
405 
406  if (s->w != s->avctx->width || s->h != s->avctx->height ||
407  new_pix_fmt != s->avctx->pix_fmt) {
408  av_frame_unref(s->frame);
409  s->avctx->sample_aspect_ratio = (AVRational){ 1 << width_shift, 1 };
410  s->avctx->pix_fmt = new_pix_fmt;
411 
412  if ((ret = ff_set_dimensions(s->avctx, s->w, s->h)) < 0)
413  return ret;
414 
415  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
416  if (!s->vert_pred)
417  return AVERROR(ENOMEM);
418  }
419 
420  /* There is 1 change bit per 4 pixels, so each change byte represents
421  * 32 pixels; divide width by 4 to obtain the number of change bits and
422  * then round up to the nearest byte. */
423  s->mb_change_bits_row_size = ((s->avctx->width >> (2 - width_shift)) + 7) >> 3;
424 
425  if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
426  {
427  if (compression_types[header.compression].algorithm == ALGO_RGB24H)
428  gen_vector_table24(s, sel_vector_table);
429  else
430  if (s->avctx->pix_fmt == AV_PIX_FMT_RGB555)
431  gen_vector_table15(s, sel_vector_table);
432  else
433  gen_vector_table16(s, sel_vector_table);
434  }
435 
436  /* set up pointers to the other key data chunks */
437  s->mb_change_bits = s->buf + header.header_size;
438  if (s->flags & FLAG_KEYFRAME) {
439  /* no change bits specified for a keyframe; only index bytes */
440  s->index_stream = s->mb_change_bits;
441  } else {
442  /* one change bit per 4x4 block */
443  s->index_stream = s->mb_change_bits +
444  (s->mb_change_bits_row_size * (s->avctx->height >> 2));
445  }
446  s->index_stream_size = s->size - (s->index_stream - s->buf);
447 
448  s->last_deltaset = header.deltaset;
449  s->last_vectable = header.vectable;
450  s->compression = header.compression;
451  s->block_width = compression_types[header.compression].block_width;
452  s->block_height = compression_types[header.compression].block_height;
453  s->block_type = compression_types[header.compression].block_type;
454 
455  if (s->avctx->debug & FF_DEBUG_PICT_INFO)
456  av_log(s->avctx, AV_LOG_INFO, "tables: %d / %d c:%d %dx%d t:%d %s%s%s%s\n",
457  s->last_deltaset, s->last_vectable, s->compression, s->block_width,
458  s->block_height, s->block_type,
459  s->flags & FLAG_KEYFRAME ? " KEY" : "",
460  s->flags & FLAG_INTERFRAME ? " INTER" : "",
461  s->flags & FLAG_SPRITE ? " SPRITE" : "",
462  s->flags & FLAG_INTERPOLATED ? " INTERPOL" : "");
463 
464  return header.header_size;
465 }
466 
467 static av_cold int truemotion1_decode_init(AVCodecContext *avctx)
468 {
469  TrueMotion1Context *s = avctx->priv_data;
470 
471  s->avctx = avctx;
472 
473  // FIXME: it may change ?
474 // if (avctx->bits_per_sample == 24)
475 // avctx->pix_fmt = AV_PIX_FMT_RGB24;
476 // else
477 // avctx->pix_fmt = AV_PIX_FMT_RGB555;
478 
479  s->frame = av_frame_alloc();
480  if (!s->frame)
481  return AVERROR(ENOMEM);
482 
483  /* there is a vertical predictor for each pixel in a line; each vertical
484  * predictor is 0 to start with */
485  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
486  if (!s->vert_pred)
487  return AVERROR(ENOMEM);
488 
489  return 0;
490 }
491 
492 /*
493 Block decoding order:
494 
495 dxi: Y-Y
496 dxic: Y-C-Y
497 dxic2: Y-C-Y-C
498 
499 hres,vres,i,i%vres (0 < i < 4)
500 2x2 0: 0 dxic2
501 2x2 1: 1 dxi
502 2x2 2: 0 dxic2
503 2x2 3: 1 dxi
504 2x4 0: 0 dxic2
505 2x4 1: 1 dxi
506 2x4 2: 2 dxi
507 2x4 3: 3 dxi
508 4x2 0: 0 dxic
509 4x2 1: 1 dxi
510 4x2 2: 0 dxic
511 4x2 3: 1 dxi
512 4x4 0: 0 dxic
513 4x4 1: 1 dxi
514 4x4 2: 2 dxi
515 4x4 3: 3 dxi
516 */
517 
518 #define GET_NEXT_INDEX() \
519 {\
520  if (index_stream_index >= s->index_stream_size) { \
521  av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
522  return; \
523  } \
524  index = s->index_stream[index_stream_index++] * 4; \
525 }
526 
527 #define INC_INDEX \
528 do { \
529  if (index >= 1023) { \
530  av_log(s->avctx, AV_LOG_ERROR, "Invalid index value.\n"); \
531  return; \
532  } \
533  index++; \
534 } while (0)
535 
536 #define APPLY_C_PREDICTOR() \
537  predictor_pair = s->c_predictor_table[index]; \
538  horiz_pred += (predictor_pair >> 1); \
539  if (predictor_pair & 1) { \
540  GET_NEXT_INDEX() \
541  if (!index) { \
542  GET_NEXT_INDEX() \
543  predictor_pair = s->c_predictor_table[index]; \
544  horiz_pred += ((predictor_pair >> 1) * 5); \
545  if (predictor_pair & 1) \
546  GET_NEXT_INDEX() \
547  else \
548  INC_INDEX; \
549  } \
550  } else \
551  INC_INDEX;
552 
553 #define APPLY_C_PREDICTOR_24() \
554  predictor_pair = s->c_predictor_table[index]; \
555  horiz_pred += (predictor_pair >> 1); \
556  if (predictor_pair & 1) { \
557  GET_NEXT_INDEX() \
558  if (!index) { \
559  GET_NEXT_INDEX() \
560  predictor_pair = s->fat_c_predictor_table[index]; \
561  horiz_pred += (predictor_pair >> 1); \
562  if (predictor_pair & 1) \
563  GET_NEXT_INDEX() \
564  else \
565  INC_INDEX; \
566  } \
567  } else \
568  INC_INDEX;
569 
570 
571 #define APPLY_Y_PREDICTOR() \
572  predictor_pair = s->y_predictor_table[index]; \
573  horiz_pred += (predictor_pair >> 1); \
574  if (predictor_pair & 1) { \
575  GET_NEXT_INDEX() \
576  if (!index) { \
577  GET_NEXT_INDEX() \
578  predictor_pair = s->y_predictor_table[index]; \
579  horiz_pred += ((predictor_pair >> 1) * 5); \
580  if (predictor_pair & 1) \
581  GET_NEXT_INDEX() \
582  else \
583  INC_INDEX; \
584  } \
585  } else \
586  INC_INDEX;
587 
588 #define APPLY_Y_PREDICTOR_24() \
589  predictor_pair = s->y_predictor_table[index]; \
590  horiz_pred += (predictor_pair >> 1); \
591  if (predictor_pair & 1) { \
592  GET_NEXT_INDEX() \
593  if (!index) { \
594  GET_NEXT_INDEX() \
595  predictor_pair = s->fat_y_predictor_table[index]; \
596  horiz_pred += (predictor_pair >> 1); \
597  if (predictor_pair & 1) \
598  GET_NEXT_INDEX() \
599  else \
600  INC_INDEX; \
601  } \
602  } else \
603  INC_INDEX;
604 
605 #define OUTPUT_PIXEL_PAIR() \
606  *current_pixel_pair = *vert_pred + horiz_pred; \
607  *vert_pred++ = *current_pixel_pair++;
608 
609 static void truemotion1_decode_16bit(TrueMotion1Context *s)
610 {
611  int y;
612  int pixels_left; /* remaining pixels on this line */
613  unsigned int predictor_pair;
614  unsigned int horiz_pred;
615  unsigned int *vert_pred;
616  unsigned int *current_pixel_pair;
617  unsigned char *current_line = s->frame->data[0];
618  int keyframe = s->flags & FLAG_KEYFRAME;
619 
620  /* these variables are for managing the stream of macroblock change bits */
621  const unsigned char *mb_change_bits = s->mb_change_bits;
622  unsigned char mb_change_byte;
623  unsigned char mb_change_byte_mask;
624  int mb_change_index;
625 
626  /* these variables are for managing the main index stream */
627  int index_stream_index = 0; /* yes, the index into the index stream */
628  int index;
629 
630  /* clean out the line buffer */
631  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
632 
633  GET_NEXT_INDEX();
634 
635  for (y = 0; y < s->avctx->height; y++) {
636 
637  /* re-init variables for the next line iteration */
638  horiz_pred = 0;
639  current_pixel_pair = (unsigned int *)current_line;
640  vert_pred = s->vert_pred;
641  mb_change_index = 0;
642  mb_change_byte = mb_change_bits[mb_change_index++];
643  mb_change_byte_mask = 0x01;
644  pixels_left = s->avctx->width;
645 
646  while (pixels_left > 0) {
647 
648  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
649 
650  switch (y & 3) {
651  case 0:
652  /* if macroblock width is 2, apply C-Y-C-Y; else
653  * apply C-Y-Y */
654  if (s->block_width == 2) {
655  APPLY_C_PREDICTOR();
656  APPLY_Y_PREDICTOR();
657  OUTPUT_PIXEL_PAIR();
658  APPLY_C_PREDICTOR();
659  APPLY_Y_PREDICTOR();
660  OUTPUT_PIXEL_PAIR();
661  } else {
662  APPLY_C_PREDICTOR();
663  APPLY_Y_PREDICTOR();
664  OUTPUT_PIXEL_PAIR();
665  APPLY_Y_PREDICTOR();
666  OUTPUT_PIXEL_PAIR();
667  }
668  break;
669 
670  case 1:
671  case 3:
672  /* always apply 2 Y predictors on these iterations */
673  APPLY_Y_PREDICTOR();
674  OUTPUT_PIXEL_PAIR();
675  APPLY_Y_PREDICTOR();
676  OUTPUT_PIXEL_PAIR();
677  break;
678 
679  case 2:
680  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
681  * depending on the macroblock type */
682  if (s->block_type == BLOCK_2x2) {
683  APPLY_C_PREDICTOR();
684  APPLY_Y_PREDICTOR();
685  OUTPUT_PIXEL_PAIR();
686  APPLY_C_PREDICTOR();
687  APPLY_Y_PREDICTOR();
688  OUTPUT_PIXEL_PAIR();
689  } else if (s->block_type == BLOCK_4x2) {
690  APPLY_C_PREDICTOR();
691  APPLY_Y_PREDICTOR();
692  OUTPUT_PIXEL_PAIR();
693  APPLY_Y_PREDICTOR();
694  OUTPUT_PIXEL_PAIR();
695  } else {
696  APPLY_Y_PREDICTOR();
697  OUTPUT_PIXEL_PAIR();
698  APPLY_Y_PREDICTOR();
699  OUTPUT_PIXEL_PAIR();
700  }
701  break;
702  }
703 
704  } else {
705 
706  /* skip (copy) four pixels, but reassign the horizontal
707  * predictor */
708  *vert_pred++ = *current_pixel_pair++;
709  horiz_pred = *current_pixel_pair - *vert_pred;
710  *vert_pred++ = *current_pixel_pair++;
711 
712  }
713 
714  if (!keyframe) {
715  mb_change_byte_mask <<= 1;
716 
717  /* next byte */
718  if (!mb_change_byte_mask) {
719  mb_change_byte = mb_change_bits[mb_change_index++];
720  mb_change_byte_mask = 0x01;
721  }
722  }
723 
724  pixels_left -= 4;
725  }
726 
727  /* next change row */
728  if (((y + 1) & 3) == 0)
729  mb_change_bits += s->mb_change_bits_row_size;
730 
731  current_line += s->frame->linesize[0];
732  }
733 }
734 
735 static void truemotion1_decode_24bit(TrueMotion1Context *s)
736 {
737  int y;
738  int pixels_left; /* remaining pixels on this line */
739  unsigned int predictor_pair;
740  unsigned int horiz_pred;
741  unsigned int *vert_pred;
742  unsigned int *current_pixel_pair;
743  unsigned char *current_line = s->frame->data[0];
744  int keyframe = s->flags & FLAG_KEYFRAME;
745 
746  /* these variables are for managing the stream of macroblock change bits */
747  const unsigned char *mb_change_bits = s->mb_change_bits;
748  unsigned char mb_change_byte;
749  unsigned char mb_change_byte_mask;
750  int mb_change_index;
751 
752  /* these variables are for managing the main index stream */
753  int index_stream_index = 0; /* yes, the index into the index stream */
754  int index;
755 
756  /* clean out the line buffer */
757  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
758 
759  GET_NEXT_INDEX();
760 
761  for (y = 0; y < s->avctx->height; y++) {
762 
763  /* re-init variables for the next line iteration */
764  horiz_pred = 0;
765  current_pixel_pair = (unsigned int *)current_line;
766  vert_pred = s->vert_pred;
767  mb_change_index = 0;
768  mb_change_byte = mb_change_bits[mb_change_index++];
769  mb_change_byte_mask = 0x01;
770  pixels_left = s->avctx->width;
771 
772  while (pixels_left > 0) {
773 
774  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
775 
776  switch (y & 3) {
777  case 0:
778  /* if macroblock width is 2, apply C-Y-C-Y; else
779  * apply C-Y-Y */
780  if (s->block_width == 2) {
781  APPLY_C_PREDICTOR_24();
782  APPLY_Y_PREDICTOR_24();
783  OUTPUT_PIXEL_PAIR();
784  APPLY_C_PREDICTOR_24();
785  APPLY_Y_PREDICTOR_24();
786  OUTPUT_PIXEL_PAIR();
787  } else {
788  APPLY_C_PREDICTOR_24();
789  APPLY_Y_PREDICTOR_24();
790  OUTPUT_PIXEL_PAIR();
791  APPLY_Y_PREDICTOR_24();
792  OUTPUT_PIXEL_PAIR();
793  }
794  break;
795 
796  case 1:
797  case 3:
798  /* always apply 2 Y predictors on these iterations */
799  APPLY_Y_PREDICTOR_24();
800  OUTPUT_PIXEL_PAIR();
801  APPLY_Y_PREDICTOR_24();
802  OUTPUT_PIXEL_PAIR();
803  break;
804 
805  case 2:
806  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
807  * depending on the macroblock type */
808  if (s->block_type == BLOCK_2x2) {
809  APPLY_C_PREDICTOR_24();
810  APPLY_Y_PREDICTOR_24();
811  OUTPUT_PIXEL_PAIR();
812  APPLY_C_PREDICTOR_24();
813  APPLY_Y_PREDICTOR_24();
814  OUTPUT_PIXEL_PAIR();
815  } else if (s->block_type == BLOCK_4x2) {
816  APPLY_C_PREDICTOR_24();
817  APPLY_Y_PREDICTOR_24();
818  OUTPUT_PIXEL_PAIR();
819  APPLY_Y_PREDICTOR_24();
820  OUTPUT_PIXEL_PAIR();
821  } else {
822  APPLY_Y_PREDICTOR_24();
823  OUTPUT_PIXEL_PAIR();
824  APPLY_Y_PREDICTOR_24();
825  OUTPUT_PIXEL_PAIR();
826  }
827  break;
828  }
829 
830  } else {
831 
832  /* skip (copy) four pixels, but reassign the horizontal
833  * predictor */
834  *vert_pred++ = *current_pixel_pair++;
835  horiz_pred = *current_pixel_pair - *vert_pred;
836  *vert_pred++ = *current_pixel_pair++;
837 
838  }
839 
840  if (!keyframe) {
841  mb_change_byte_mask <<= 1;
842 
843  /* next byte */
844  if (!mb_change_byte_mask) {
845  mb_change_byte = mb_change_bits[mb_change_index++];
846  mb_change_byte_mask = 0x01;
847  }
848  }
849 
850  pixels_left -= 2;
851  }
852 
853  /* next change row */
854  if (((y + 1) & 3) == 0)
855  mb_change_bits += s->mb_change_bits_row_size;
856 
857  current_line += s->frame->linesize[0];
858  }
859 }
860 
861 
862 static int truemotion1_decode_frame(AVCodecContext *avctx,
863  void *data, int *got_frame,
864  AVPacket *avpkt)
865 {
866  const uint8_t *buf = avpkt->data;
867  int ret, buf_size = avpkt->size;
868  TrueMotion1Context *s = avctx->priv_data;
869 
870  s->buf = buf;
871  s->size = buf_size;
872 
873  if ((ret = truemotion1_decode_header(s)) < 0)
874  return ret;
875 
876  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
877  return ret;
878 
879  if (compression_types[s->compression].algorithm == ALGO_RGB24H) {
880  truemotion1_decode_24bit(s);
881  } else if (compression_types[s->compression].algorithm != ALGO_NOP) {
882  truemotion1_decode_16bit(s);
883  }
884 
885  if ((ret = av_frame_ref(data, s->frame)) < 0)
886  return ret;
887 
888  *got_frame = 1;
889 
890  /* report that the buffer was completely consumed */
891  return buf_size;
892 }
893 
894 static av_cold int truemotion1_decode_end(AVCodecContext *avctx)
895 {
896  TrueMotion1Context *s = avctx->priv_data;
897 
898  av_frame_free(&s->frame);
899  av_freep(&s->vert_pred);
900 
901  return 0;
902 }
903 
904 AVCodec ff_truemotion1_decoder = {
905  .name = "truemotion1",
906  .long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 1.0"),
907  .type = AVMEDIA_TYPE_VIDEO,
908  .id = AV_CODEC_ID_TRUEMOTION1,
909  .priv_data_size = sizeof(TrueMotion1Context),
910  .init = truemotion1_decode_init,
911  .close = truemotion1_decode_end,
912  .decode = truemotion1_decode_frame,
913  .capabilities = CODEC_CAP_DR1,
914 };
Generated on Sun Mar 23 2014 23:50:03 for FFmpeg by   doxygen 1.8.2