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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 "libavutil/imgutils.h"
38 #include "libavutil/internal.h"
39 #include "libavutil/intreadwrite.h"
40 #include "libavutil/mem.h"
41 
42 #include "truemotion1data.h"
43 
44 typedef struct TrueMotion1Context {
45  AVCodecContext *avctx;
46  AVFrame frame;
47 
48  const uint8_t *buf;
49  int size;
50 
51  const uint8_t *mb_change_bits;
52  int mb_change_bits_row_size;
53  const uint8_t *index_stream;
54  int index_stream_size;
55 
56  int flags;
57  int x, y, w, h;
58 
59  uint32_t y_predictor_table[1024];
60  uint32_t c_predictor_table[1024];
61  uint32_t fat_y_predictor_table[1024];
62  uint32_t fat_c_predictor_table[1024];
63 
64  int compression;
65  int block_type;
66  int block_width;
67  int block_height;
68 
69  int16_t ydt[8];
70  int16_t cdt[8];
71  int16_t fat_ydt[8];
72  int16_t fat_cdt[8];
73 
74  int last_deltaset, last_vectable;
75 
76  unsigned int *vert_pred;
77  int vert_pred_size;
78 
79 } TrueMotion1Context;
80 
81 #define FLAG_SPRITE 32
82 #define FLAG_KEYFRAME 16
83 #define FLAG_INTERFRAME 8
84 #define FLAG_INTERPOLATED 4
85 
86 struct frame_header {
87  uint8_t header_size;
88  uint8_t compression;
89  uint8_t deltaset;
90  uint8_t vectable;
91  uint16_t ysize;
92  uint16_t xsize;
93  uint16_t checksum;
94  uint8_t version;
95  uint8_t header_type;
96  uint8_t flags;
97  uint8_t control;
98  uint16_t xoffset;
99  uint16_t yoffset;
100  uint16_t width;
101  uint16_t height;
102 };
103 
104 #define ALGO_NOP 0
105 #define ALGO_RGB16V 1
106 #define ALGO_RGB16H 2
107 #define ALGO_RGB24H 3
108 
109 /* these are the various block sizes that can occupy a 4x4 block */
110 #define BLOCK_2x2 0
111 #define BLOCK_2x4 1
112 #define BLOCK_4x2 2
113 #define BLOCK_4x4 3
114 
115 typedef struct comp_types {
116  int algorithm;
117  int block_width; // vres
118  int block_height; // hres
119  int block_type;
120 } comp_types;
121 
122 /* { valid for metatype }, algorithm, num of deltas, vert res, horiz res */
123 static const comp_types compression_types[17] = {
124  { ALGO_NOP, 0, 0, 0 },
125 
126  { ALGO_RGB16V, 4, 4, BLOCK_4x4 },
127  { ALGO_RGB16H, 4, 4, BLOCK_4x4 },
128  { ALGO_RGB16V, 4, 2, BLOCK_4x2 },
129  { ALGO_RGB16H, 4, 2, BLOCK_4x2 },
130 
131  { ALGO_RGB16V, 2, 4, BLOCK_2x4 },
132  { ALGO_RGB16H, 2, 4, BLOCK_2x4 },
133  { ALGO_RGB16V, 2, 2, BLOCK_2x2 },
134  { ALGO_RGB16H, 2, 2, BLOCK_2x2 },
135 
136  { ALGO_NOP, 4, 4, BLOCK_4x4 },
137  { ALGO_RGB24H, 4, 4, BLOCK_4x4 },
138  { ALGO_NOP, 4, 2, BLOCK_4x2 },
139  { ALGO_RGB24H, 4, 2, BLOCK_4x2 },
140 
141  { ALGO_NOP, 2, 4, BLOCK_2x4 },
142  { ALGO_RGB24H, 2, 4, BLOCK_2x4 },
143  { ALGO_NOP, 2, 2, BLOCK_2x2 },
144  { ALGO_RGB24H, 2, 2, BLOCK_2x2 }
145 };
146 
147 static void select_delta_tables(TrueMotion1Context *s, int delta_table_index)
148 {
149  int i;
150 
151  if (delta_table_index > 3)
152  return;
153 
154  memcpy(s->ydt, ydts[delta_table_index], 8 * sizeof(int16_t));
155  memcpy(s->cdt, cdts[delta_table_index], 8 * sizeof(int16_t));
156  memcpy(s->fat_ydt, fat_ydts[delta_table_index], 8 * sizeof(int16_t));
157  memcpy(s->fat_cdt, fat_cdts[delta_table_index], 8 * sizeof(int16_t));
158 
159  /* Y skinny deltas need to be halved for some reason; maybe the
160  * skinny Y deltas should be modified */
161  for (i = 0; i < 8; i++)
162  {
163  /* drop the lsb before dividing by 2-- net effect: round down
164  * when dividing a negative number (e.g., -3/2 = -2, not -1) */
165  s->ydt[i] &= 0xFFFE;
166  s->ydt[i] /= 2;
167  }
168 }
169 
170 #if HAVE_BIGENDIAN
171 static int make_ydt15_entry(int p2, int p1, int16_t *ydt)
172 #else
173 static int make_ydt15_entry(int p1, int p2, int16_t *ydt)
174 #endif
175 {
176  int lo, hi;
177 
178  lo = ydt[p1];
179  lo += (lo << 5) + (lo << 10);
180  hi = ydt[p2];
181  hi += (hi << 5) + (hi << 10);
182  return (lo + (hi << 16)) << 1;
183 }
184 
185 static int make_cdt15_entry(int p1, int p2, int16_t *cdt)
186 {
187  int r, b, lo;
188 
189  b = cdt[p2];
190  r = cdt[p1] << 10;
191  lo = b + r;
192  return (lo + (lo << 16)) << 1;
193 }
194 
195 #if HAVE_BIGENDIAN
196 static int make_ydt16_entry(int p2, int p1, int16_t *ydt)
197 #else
198 static int make_ydt16_entry(int p1, int p2, int16_t *ydt)
199 #endif
200 {
201  int lo, hi;
202 
203  lo = ydt[p1];
204  lo += (lo << 6) + (lo << 11);
205  hi = ydt[p2];
206  hi += (hi << 6) + (hi << 11);
207  return (lo + (hi << 16)) << 1;
208 }
209 
210 static int make_cdt16_entry(int p1, int p2, int16_t *cdt)
211 {
212  int r, b, lo;
213 
214  b = cdt[p2];
215  r = cdt[p1] << 11;
216  lo = b + r;
217  return (lo + (lo << 16)) << 1;
218 }
219 
220 static int make_ydt24_entry(int p1, int p2, int16_t *ydt)
221 {
222  int lo, hi;
223 
224  lo = ydt[p1];
225  hi = ydt[p2];
226  return (lo + (hi << 8) + (hi << 16)) << 1;
227 }
228 
229 static int make_cdt24_entry(int p1, int p2, int16_t *cdt)
230 {
231  int r, b;
232 
233  b = cdt[p2];
234  r = cdt[p1]<<16;
235  return (b+r) << 1;
236 }
237 
238 static void gen_vector_table15(TrueMotion1Context *s, const uint8_t *sel_vector_table)
239 {
240  int len, i, j;
241  unsigned char delta_pair;
242 
243  for (i = 0; i < 1024; i += 4)
244  {
245  len = *sel_vector_table++ / 2;
246  for (j = 0; j < len; j++)
247  {
248  delta_pair = *sel_vector_table++;
249  s->y_predictor_table[i+j] = 0xfffffffe &
250  make_ydt15_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
251  s->c_predictor_table[i+j] = 0xfffffffe &
252  make_cdt15_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
253  }
254  s->y_predictor_table[i+(j-1)] |= 1;
255  s->c_predictor_table[i+(j-1)] |= 1;
256  }
257 }
258 
259 static void gen_vector_table16(TrueMotion1Context *s, const uint8_t *sel_vector_table)
260 {
261  int len, i, j;
262  unsigned char delta_pair;
263 
264  for (i = 0; i < 1024; i += 4)
265  {
266  len = *sel_vector_table++ / 2;
267  for (j = 0; j < len; j++)
268  {
269  delta_pair = *sel_vector_table++;
270  s->y_predictor_table[i+j] = 0xfffffffe &
271  make_ydt16_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
272  s->c_predictor_table[i+j] = 0xfffffffe &
273  make_cdt16_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
274  }
275  s->y_predictor_table[i+(j-1)] |= 1;
276  s->c_predictor_table[i+(j-1)] |= 1;
277  }
278 }
279 
280 static void gen_vector_table24(TrueMotion1Context *s, const uint8_t *sel_vector_table)
281 {
282  int len, i, j;
283  unsigned char delta_pair;
284 
285  for (i = 0; i < 1024; i += 4)
286  {
287  len = *sel_vector_table++ / 2;
288  for (j = 0; j < len; j++)
289  {
290  delta_pair = *sel_vector_table++;
291  s->y_predictor_table[i+j] = 0xfffffffe &
292  make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
293  s->c_predictor_table[i+j] = 0xfffffffe &
294  make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
295  s->fat_y_predictor_table[i+j] = 0xfffffffe &
296  make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_ydt);
297  s->fat_c_predictor_table[i+j] = 0xfffffffe &
298  make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_cdt);
299  }
300  s->y_predictor_table[i+(j-1)] |= 1;
301  s->c_predictor_table[i+(j-1)] |= 1;
302  s->fat_y_predictor_table[i+(j-1)] |= 1;
303  s->fat_c_predictor_table[i+(j-1)] |= 1;
304  }
305 }
306 
307 /* Returns the number of bytes consumed from the bytestream. Returns -1 if
308  * there was an error while decoding the header */
309 static int truemotion1_decode_header(TrueMotion1Context *s)
310 {
311  int i, ret;
312  int width_shift = 0;
313  int new_pix_fmt;
314  struct frame_header header;
315  uint8_t header_buffer[128] = { 0 }; /* logical maximum size of the header */
316  const uint8_t *sel_vector_table;
317 
318  header.header_size = ((s->buf[0] >> 5) | (s->buf[0] << 3)) & 0x7f;
319  if (s->buf[0] < 0x10 || header.header_size >= s->size)
320  {
321  av_log(s->avctx, AV_LOG_ERROR, "invalid header size (%d)\n", s->buf[0]);
322  return AVERROR_INVALIDDATA;
323  }
324 
325  /* unscramble the header bytes with a XOR operation */
326  for (i = 1; i < header.header_size; i++)
327  header_buffer[i - 1] = s->buf[i] ^ s->buf[i + 1];
328 
329  header.compression = header_buffer[0];
330  header.deltaset = header_buffer[1];
331  header.vectable = header_buffer[2];
332  header.ysize = AV_RL16(&header_buffer[3]);
333  header.xsize = AV_RL16(&header_buffer[5]);
334  header.checksum = AV_RL16(&header_buffer[7]);
335  header.version = header_buffer[9];
336  header.header_type = header_buffer[10];
337  header.flags = header_buffer[11];
338  header.control = header_buffer[12];
339 
340  /* Version 2 */
341  if (header.version >= 2)
342  {
343  if (header.header_type > 3)
344  {
345  av_log(s->avctx, AV_LOG_ERROR, "invalid header type (%d)\n", header.header_type);
346  return AVERROR_INVALIDDATA;
347  } else if ((header.header_type == 2) || (header.header_type == 3)) {
348  s->flags = header.flags;
349  if (!(s->flags & FLAG_INTERFRAME))
350  s->flags |= FLAG_KEYFRAME;
351  } else
352  s->flags = FLAG_KEYFRAME;
353  } else /* Version 1 */
354  s->flags = FLAG_KEYFRAME;
355 
356  if (s->flags & FLAG_SPRITE) {
357  av_log_ask_for_sample(s->avctx, "SPRITE frame found.\n");
358  /* FIXME header.width, height, xoffset and yoffset aren't initialized */
359  return AVERROR_PATCHWELCOME;
360  } else {
361  s->w = header.xsize;
362  s->h = header.ysize;
363  if (header.header_type < 2) {
364  if ((s->w < 213) && (s->h >= 176))
365  {
366  s->flags |= FLAG_INTERPOLATED;
367  av_log_ask_for_sample(s->avctx, "INTERPOLATION selected.\n");
368  }
369  }
370  }
371 
372  if (header.compression >= 17) {
373  av_log(s->avctx, AV_LOG_ERROR, "invalid compression type (%d)\n", header.compression);
374  return AVERROR_INVALIDDATA;
375  }
376 
377  if ((header.deltaset != s->last_deltaset) ||
378  (header.vectable != s->last_vectable))
379  select_delta_tables(s, header.deltaset);
380 
381  if ((header.compression & 1) && header.header_type)
382  sel_vector_table = pc_tbl2;
383  else {
384  if (header.vectable > 0 && header.vectable < 4)
385  sel_vector_table = tables[header.vectable - 1];
386  else {
387  av_log(s->avctx, AV_LOG_ERROR, "invalid vector table id (%d)\n", header.vectable);
388  return AVERROR_INVALIDDATA;
389  }
390  }
391 
392  if (compression_types[header.compression].algorithm == ALGO_RGB24H) {
393  new_pix_fmt = AV_PIX_FMT_RGB32;
394  width_shift = 1;
395  } else
396  new_pix_fmt = AV_PIX_FMT_RGB555; // RGB565 is supported as well
397 
398  s->w >>= width_shift;
399  if ((ret = av_image_check_size(s->w, s->h, 0, s->avctx)) < 0)
400  return ret;
401 
402  if (s->w != s->avctx->width || s->h != s->avctx->height ||
403  new_pix_fmt != s->avctx->pix_fmt) {
404  if (s->frame.data[0])
405  s->avctx->release_buffer(s->avctx, &s->frame);
406  s->avctx->sample_aspect_ratio = (AVRational){ 1 << width_shift, 1 };
407  s->avctx->pix_fmt = new_pix_fmt;
408  avcodec_set_dimensions(s->avctx, s->w, s->h);
409  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
410  }
411 
412  /* There is 1 change bit per 4 pixels, so each change byte represents
413  * 32 pixels; divide width by 4 to obtain the number of change bits and
414  * then round up to the nearest byte. */
415  s->mb_change_bits_row_size = ((s->avctx->width >> (2 - width_shift)) + 7) >> 3;
416 
417  if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
418  {
419  if (compression_types[header.compression].algorithm == ALGO_RGB24H)
420  gen_vector_table24(s, sel_vector_table);
421  else
422  if (s->avctx->pix_fmt == AV_PIX_FMT_RGB555)
423  gen_vector_table15(s, sel_vector_table);
424  else
425  gen_vector_table16(s, sel_vector_table);
426  }
427 
428  /* set up pointers to the other key data chunks */
429  s->mb_change_bits = s->buf + header.header_size;
430  if (s->flags & FLAG_KEYFRAME) {
431  /* no change bits specified for a keyframe; only index bytes */
432  s->index_stream = s->mb_change_bits;
433  } else {
434  /* one change bit per 4x4 block */
435  s->index_stream = s->mb_change_bits +
436  (s->mb_change_bits_row_size * (s->avctx->height >> 2));
437  }
438  s->index_stream_size = s->size - (s->index_stream - s->buf);
439 
440  s->last_deltaset = header.deltaset;
441  s->last_vectable = header.vectable;
442  s->compression = header.compression;
443  s->block_width = compression_types[header.compression].block_width;
444  s->block_height = compression_types[header.compression].block_height;
445  s->block_type = compression_types[header.compression].block_type;
446 
447  if (s->avctx->debug & FF_DEBUG_PICT_INFO)
448  av_log(s->avctx, AV_LOG_INFO, "tables: %d / %d c:%d %dx%d t:%d %s%s%s%s\n",
449  s->last_deltaset, s->last_vectable, s->compression, s->block_width,
450  s->block_height, s->block_type,
451  s->flags & FLAG_KEYFRAME ? " KEY" : "",
452  s->flags & FLAG_INTERFRAME ? " INTER" : "",
453  s->flags & FLAG_SPRITE ? " SPRITE" : "",
454  s->flags & FLAG_INTERPOLATED ? " INTERPOL" : "");
455 
456  return header.header_size;
457 }
458 
459 static av_cold int truemotion1_decode_init(AVCodecContext *avctx)
460 {
461  TrueMotion1Context *s = avctx->priv_data;
462 
463  s->avctx = avctx;
464 
465  // FIXME: it may change ?
466 // if (avctx->bits_per_sample == 24)
467 // avctx->pix_fmt = AV_PIX_FMT_RGB24;
468 // else
469 // avctx->pix_fmt = AV_PIX_FMT_RGB555;
470 
471  avcodec_get_frame_defaults(&s->frame);
472  s->frame.data[0] = NULL;
473 
474  /* there is a vertical predictor for each pixel in a line; each vertical
475  * predictor is 0 to start with */
476  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
477 
478  return 0;
479 }
480 
481 /*
482 Block decoding order:
483 
484 dxi: Y-Y
485 dxic: Y-C-Y
486 dxic2: Y-C-Y-C
487 
488 hres,vres,i,i%vres (0 < i < 4)
489 2x2 0: 0 dxic2
490 2x2 1: 1 dxi
491 2x2 2: 0 dxic2
492 2x2 3: 1 dxi
493 2x4 0: 0 dxic2
494 2x4 1: 1 dxi
495 2x4 2: 2 dxi
496 2x4 3: 3 dxi
497 4x2 0: 0 dxic
498 4x2 1: 1 dxi
499 4x2 2: 0 dxic
500 4x2 3: 1 dxi
501 4x4 0: 0 dxic
502 4x4 1: 1 dxi
503 4x4 2: 2 dxi
504 4x4 3: 3 dxi
505 */
506 
507 #define GET_NEXT_INDEX() \
508 {\
509  if (index_stream_index >= s->index_stream_size) { \
510  av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
511  return; \
512  } \
513  index = s->index_stream[index_stream_index++] * 4; \
514 }
515 
516 #define APPLY_C_PREDICTOR() \
517  if(index > 1023){\
518  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
519  return; \
520  }\
521  predictor_pair = s->c_predictor_table[index]; \
522  horiz_pred += (predictor_pair >> 1); \
523  if (predictor_pair & 1) { \
524  GET_NEXT_INDEX() \
525  if (!index) { \
526  GET_NEXT_INDEX() \
527  predictor_pair = s->c_predictor_table[index]; \
528  horiz_pred += ((predictor_pair >> 1) * 5); \
529  if (predictor_pair & 1) \
530  GET_NEXT_INDEX() \
531  else \
532  index++; \
533  } \
534  } else \
535  index++;
536 
537 #define APPLY_C_PREDICTOR_24() \
538  if(index > 1023){\
539  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
540  return; \
541  }\
542  predictor_pair = s->c_predictor_table[index]; \
543  horiz_pred += (predictor_pair >> 1); \
544  if (predictor_pair & 1) { \
545  GET_NEXT_INDEX() \
546  if (!index) { \
547  GET_NEXT_INDEX() \
548  predictor_pair = s->fat_c_predictor_table[index]; \
549  horiz_pred += (predictor_pair >> 1); \
550  if (predictor_pair & 1) \
551  GET_NEXT_INDEX() \
552  else \
553  index++; \
554  } \
555  } else \
556  index++;
557 
558 
559 #define APPLY_Y_PREDICTOR() \
560  if(index > 1023){\
561  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
562  return; \
563  }\
564  predictor_pair = s->y_predictor_table[index]; \
565  horiz_pred += (predictor_pair >> 1); \
566  if (predictor_pair & 1) { \
567  GET_NEXT_INDEX() \
568  if (!index) { \
569  GET_NEXT_INDEX() \
570  predictor_pair = s->y_predictor_table[index]; \
571  horiz_pred += ((predictor_pair >> 1) * 5); \
572  if (predictor_pair & 1) \
573  GET_NEXT_INDEX() \
574  else \
575  index++; \
576  } \
577  } else \
578  index++;
579 
580 #define APPLY_Y_PREDICTOR_24() \
581  if(index > 1023){\
582  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
583  return; \
584  }\
585  predictor_pair = s->y_predictor_table[index]; \
586  horiz_pred += (predictor_pair >> 1); \
587  if (predictor_pair & 1) { \
588  GET_NEXT_INDEX() \
589  if (!index) { \
590  GET_NEXT_INDEX() \
591  predictor_pair = s->fat_y_predictor_table[index]; \
592  horiz_pred += (predictor_pair >> 1); \
593  if (predictor_pair & 1) \
594  GET_NEXT_INDEX() \
595  else \
596  index++; \
597  } \
598  } else \
599  index++;
600 
601 #define OUTPUT_PIXEL_PAIR() \
602  *current_pixel_pair = *vert_pred + horiz_pred; \
603  *vert_pred++ = *current_pixel_pair++;
604 
605 static void truemotion1_decode_16bit(TrueMotion1Context *s)
606 {
607  int y;
608  int pixels_left; /* remaining pixels on this line */
609  unsigned int predictor_pair;
610  unsigned int horiz_pred;
611  unsigned int *vert_pred;
612  unsigned int *current_pixel_pair;
613  unsigned char *current_line = s->frame.data[0];
614  int keyframe = s->flags & FLAG_KEYFRAME;
615 
616  /* these variables are for managing the stream of macroblock change bits */
617  const unsigned char *mb_change_bits = s->mb_change_bits;
618  unsigned char mb_change_byte;
619  unsigned char mb_change_byte_mask;
620  int mb_change_index;
621 
622  /* these variables are for managing the main index stream */
623  int index_stream_index = 0; /* yes, the index into the index stream */
624  int index;
625 
626  /* clean out the line buffer */
627  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
628 
629  GET_NEXT_INDEX();
630 
631  for (y = 0; y < s->avctx->height; y++) {
632 
633  /* re-init variables for the next line iteration */
634  horiz_pred = 0;
635  current_pixel_pair = (unsigned int *)current_line;
636  vert_pred = s->vert_pred;
637  mb_change_index = 0;
638  mb_change_byte = mb_change_bits[mb_change_index++];
639  mb_change_byte_mask = 0x01;
640  pixels_left = s->avctx->width;
641 
642  while (pixels_left > 0) {
643 
644  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
645 
646  switch (y & 3) {
647  case 0:
648  /* if macroblock width is 2, apply C-Y-C-Y; else
649  * apply C-Y-Y */
650  if (s->block_width == 2) {
651  APPLY_C_PREDICTOR();
652  APPLY_Y_PREDICTOR();
653  OUTPUT_PIXEL_PAIR();
654  APPLY_C_PREDICTOR();
655  APPLY_Y_PREDICTOR();
656  OUTPUT_PIXEL_PAIR();
657  } else {
658  APPLY_C_PREDICTOR();
659  APPLY_Y_PREDICTOR();
660  OUTPUT_PIXEL_PAIR();
661  APPLY_Y_PREDICTOR();
662  OUTPUT_PIXEL_PAIR();
663  }
664  break;
665 
666  case 1:
667  case 3:
668  /* always apply 2 Y predictors on these iterations */
669  APPLY_Y_PREDICTOR();
670  OUTPUT_PIXEL_PAIR();
671  APPLY_Y_PREDICTOR();
672  OUTPUT_PIXEL_PAIR();
673  break;
674 
675  case 2:
676  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
677  * depending on the macroblock type */
678  if (s->block_type == BLOCK_2x2) {
679  APPLY_C_PREDICTOR();
680  APPLY_Y_PREDICTOR();
681  OUTPUT_PIXEL_PAIR();
682  APPLY_C_PREDICTOR();
683  APPLY_Y_PREDICTOR();
684  OUTPUT_PIXEL_PAIR();
685  } else if (s->block_type == BLOCK_4x2) {
686  APPLY_C_PREDICTOR();
687  APPLY_Y_PREDICTOR();
688  OUTPUT_PIXEL_PAIR();
689  APPLY_Y_PREDICTOR();
690  OUTPUT_PIXEL_PAIR();
691  } else {
692  APPLY_Y_PREDICTOR();
693  OUTPUT_PIXEL_PAIR();
694  APPLY_Y_PREDICTOR();
695  OUTPUT_PIXEL_PAIR();
696  }
697  break;
698  }
699 
700  } else {
701 
702  /* skip (copy) four pixels, but reassign the horizontal
703  * predictor */
704  *vert_pred++ = *current_pixel_pair++;
705  horiz_pred = *current_pixel_pair - *vert_pred;
706  *vert_pred++ = *current_pixel_pair++;
707 
708  }
709 
710  if (!keyframe) {
711  mb_change_byte_mask <<= 1;
712 
713  /* next byte */
714  if (!mb_change_byte_mask) {
715  mb_change_byte = mb_change_bits[mb_change_index++];
716  mb_change_byte_mask = 0x01;
717  }
718  }
719 
720  pixels_left -= 4;
721  }
722 
723  /* next change row */
724  if (((y + 1) & 3) == 0)
725  mb_change_bits += s->mb_change_bits_row_size;
726 
727  current_line += s->frame.linesize[0];
728  }
729 }
730 
731 static void truemotion1_decode_24bit(TrueMotion1Context *s)
732 {
733  int y;
734  int pixels_left; /* remaining pixels on this line */
735  unsigned int predictor_pair;
736  unsigned int horiz_pred;
737  unsigned int *vert_pred;
738  unsigned int *current_pixel_pair;
739  unsigned char *current_line = s->frame.data[0];
740  int keyframe = s->flags & FLAG_KEYFRAME;
741 
742  /* these variables are for managing the stream of macroblock change bits */
743  const unsigned char *mb_change_bits = s->mb_change_bits;
744  unsigned char mb_change_byte;
745  unsigned char mb_change_byte_mask;
746  int mb_change_index;
747 
748  /* these variables are for managing the main index stream */
749  int index_stream_index = 0; /* yes, the index into the index stream */
750  int index;
751 
752  /* clean out the line buffer */
753  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
754 
755  GET_NEXT_INDEX();
756 
757  for (y = 0; y < s->avctx->height; y++) {
758 
759  /* re-init variables for the next line iteration */
760  horiz_pred = 0;
761  current_pixel_pair = (unsigned int *)current_line;
762  vert_pred = s->vert_pred;
763  mb_change_index = 0;
764  mb_change_byte = mb_change_bits[mb_change_index++];
765  mb_change_byte_mask = 0x01;
766  pixels_left = s->avctx->width;
767 
768  while (pixels_left > 0) {
769 
770  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
771 
772  switch (y & 3) {
773  case 0:
774  /* if macroblock width is 2, apply C-Y-C-Y; else
775  * apply C-Y-Y */
776  if (s->block_width == 2) {
777  APPLY_C_PREDICTOR_24();
778  APPLY_Y_PREDICTOR_24();
779  OUTPUT_PIXEL_PAIR();
780  APPLY_C_PREDICTOR_24();
781  APPLY_Y_PREDICTOR_24();
782  OUTPUT_PIXEL_PAIR();
783  } else {
784  APPLY_C_PREDICTOR_24();
785  APPLY_Y_PREDICTOR_24();
786  OUTPUT_PIXEL_PAIR();
787  APPLY_Y_PREDICTOR_24();
788  OUTPUT_PIXEL_PAIR();
789  }
790  break;
791 
792  case 1:
793  case 3:
794  /* always apply 2 Y predictors on these iterations */
795  APPLY_Y_PREDICTOR_24();
796  OUTPUT_PIXEL_PAIR();
797  APPLY_Y_PREDICTOR_24();
798  OUTPUT_PIXEL_PAIR();
799  break;
800 
801  case 2:
802  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
803  * depending on the macroblock type */
804  if (s->block_type == BLOCK_2x2) {
805  APPLY_C_PREDICTOR_24();
806  APPLY_Y_PREDICTOR_24();
807  OUTPUT_PIXEL_PAIR();
808  APPLY_C_PREDICTOR_24();
809  APPLY_Y_PREDICTOR_24();
810  OUTPUT_PIXEL_PAIR();
811  } else if (s->block_type == BLOCK_4x2) {
812  APPLY_C_PREDICTOR_24();
813  APPLY_Y_PREDICTOR_24();
814  OUTPUT_PIXEL_PAIR();
815  APPLY_Y_PREDICTOR_24();
816  OUTPUT_PIXEL_PAIR();
817  } else {
818  APPLY_Y_PREDICTOR_24();
819  OUTPUT_PIXEL_PAIR();
820  APPLY_Y_PREDICTOR_24();
821  OUTPUT_PIXEL_PAIR();
822  }
823  break;
824  }
825 
826  } else {
827 
828  /* skip (copy) four pixels, but reassign the horizontal
829  * predictor */
830  *vert_pred++ = *current_pixel_pair++;
831  horiz_pred = *current_pixel_pair - *vert_pred;
832  *vert_pred++ = *current_pixel_pair++;
833 
834  }
835 
836  if (!keyframe) {
837  mb_change_byte_mask <<= 1;
838 
839  /* next byte */
840  if (!mb_change_byte_mask) {
841  mb_change_byte = mb_change_bits[mb_change_index++];
842  mb_change_byte_mask = 0x01;
843  }
844  }
845 
846  pixels_left -= 2;
847  }
848 
849  /* next change row */
850  if (((y + 1) & 3) == 0)
851  mb_change_bits += s->mb_change_bits_row_size;
852 
853  current_line += s->frame.linesize[0];
854  }
855 }
856 
857 
858 static int truemotion1_decode_frame(AVCodecContext *avctx,
859  void *data, int *got_frame,
860  AVPacket *avpkt)
861 {
862  const uint8_t *buf = avpkt->data;
863  int ret, buf_size = avpkt->size;
864  TrueMotion1Context *s = avctx->priv_data;
865 
866  s->buf = buf;
867  s->size = buf_size;
868 
869  if ((ret = truemotion1_decode_header(s)) < 0)
870  return ret;
871 
872  s->frame.reference = 3;
873  s->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
874  FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
875  if ((ret = avctx->reget_buffer(avctx, &s->frame)) < 0) {
876  av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
877  return ret;
878  }
879 
880  if (compression_types[s->compression].algorithm == ALGO_RGB24H) {
881  truemotion1_decode_24bit(s);
882  } else if (compression_types[s->compression].algorithm != ALGO_NOP) {
883  truemotion1_decode_16bit(s);
884  }
885 
886  *got_frame = 1;
887  *(AVFrame*)data = s->frame;
888 
889  /* report that the buffer was completely consumed */
890  return buf_size;
891 }
892 
893 static av_cold int truemotion1_decode_end(AVCodecContext *avctx)
894 {
895  TrueMotion1Context *s = avctx->priv_data;
896 
897  if (s->frame.data[0])
898  avctx->release_buffer(avctx, &s->frame);
899 
900  av_free(s->vert_pred);
901 
902  return 0;
903 }
904 
905 AVCodec ff_truemotion1_decoder = {
906  .name = "truemotion1",
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  .long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 1.0"),
915 };
Generated on Sat May 25 2013 04:01:11 for FFmpeg by   doxygen 1.8.2