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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  ff_set_sar(s->avctx, s->avctx->sample_aspect_ratio);
416 
417  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
418  if (!s->vert_pred)
419  return AVERROR(ENOMEM);
420  }
421 
422  /* There is 1 change bit per 4 pixels, so each change byte represents
423  * 32 pixels; divide width by 4 to obtain the number of change bits and
424  * then round up to the nearest byte. */
425  s->mb_change_bits_row_size = ((s->avctx->width >> (2 - width_shift)) + 7) >> 3;
426 
427  if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
428  {
429  if (compression_types[header.compression].algorithm == ALGO_RGB24H)
430  gen_vector_table24(s, sel_vector_table);
431  else
432  if (s->avctx->pix_fmt == AV_PIX_FMT_RGB555)
433  gen_vector_table15(s, sel_vector_table);
434  else
435  gen_vector_table16(s, sel_vector_table);
436  }
437 
438  /* set up pointers to the other key data chunks */
439  s->mb_change_bits = s->buf + header.header_size;
440  if (s->flags & FLAG_KEYFRAME) {
441  /* no change bits specified for a keyframe; only index bytes */
442  s->index_stream = s->mb_change_bits;
443  } else {
444  /* one change bit per 4x4 block */
445  s->index_stream = s->mb_change_bits +
446  (s->mb_change_bits_row_size * (s->avctx->height >> 2));
447  }
448  s->index_stream_size = s->size - (s->index_stream - s->buf);
449 
450  s->last_deltaset = header.deltaset;
451  s->last_vectable = header.vectable;
452  s->compression = header.compression;
453  s->block_width = compression_types[header.compression].block_width;
454  s->block_height = compression_types[header.compression].block_height;
455  s->block_type = compression_types[header.compression].block_type;
456 
457  if (s->avctx->debug & FF_DEBUG_PICT_INFO)
458  av_log(s->avctx, AV_LOG_INFO, "tables: %d / %d c:%d %dx%d t:%d %s%s%s%s\n",
459  s->last_deltaset, s->last_vectable, s->compression, s->block_width,
460  s->block_height, s->block_type,
461  s->flags & FLAG_KEYFRAME ? " KEY" : "",
462  s->flags & FLAG_INTERFRAME ? " INTER" : "",
463  s->flags & FLAG_SPRITE ? " SPRITE" : "",
464  s->flags & FLAG_INTERPOLATED ? " INTERPOL" : "");
465 
466  return header.header_size;
467 }
468 
469 static av_cold int truemotion1_decode_init(AVCodecContext *avctx)
470 {
471  TrueMotion1Context *s = avctx->priv_data;
472 
473  s->avctx = avctx;
474 
475  // FIXME: it may change ?
476 // if (avctx->bits_per_sample == 24)
477 // avctx->pix_fmt = AV_PIX_FMT_RGB24;
478 // else
479 // avctx->pix_fmt = AV_PIX_FMT_RGB555;
480 
481  s->frame = av_frame_alloc();
482  if (!s->frame)
483  return AVERROR(ENOMEM);
484 
485  /* there is a vertical predictor for each pixel in a line; each vertical
486  * predictor is 0 to start with */
487  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
488  if (!s->vert_pred)
489  return AVERROR(ENOMEM);
490 
491  return 0;
492 }
493 
494 /*
495 Block decoding order:
496 
497 dxi: Y-Y
498 dxic: Y-C-Y
499 dxic2: Y-C-Y-C
500 
501 hres,vres,i,i%vres (0 < i < 4)
502 2x2 0: 0 dxic2
503 2x2 1: 1 dxi
504 2x2 2: 0 dxic2
505 2x2 3: 1 dxi
506 2x4 0: 0 dxic2
507 2x4 1: 1 dxi
508 2x4 2: 2 dxi
509 2x4 3: 3 dxi
510 4x2 0: 0 dxic
511 4x2 1: 1 dxi
512 4x2 2: 0 dxic
513 4x2 3: 1 dxi
514 4x4 0: 0 dxic
515 4x4 1: 1 dxi
516 4x4 2: 2 dxi
517 4x4 3: 3 dxi
518 */
519 
520 #define GET_NEXT_INDEX() \
521 {\
522  if (index_stream_index >= s->index_stream_size) { \
523  av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
524  return; \
525  } \
526  index = s->index_stream[index_stream_index++] * 4; \
527 }
528 
529 #define INC_INDEX \
530 do { \
531  if (index >= 1023) { \
532  av_log(s->avctx, AV_LOG_ERROR, "Invalid index value.\n"); \
533  return; \
534  } \
535  index++; \
536 } while (0)
537 
538 #define APPLY_C_PREDICTOR() \
539  predictor_pair = s->c_predictor_table[index]; \
540  horiz_pred += (predictor_pair >> 1); \
541  if (predictor_pair & 1) { \
542  GET_NEXT_INDEX() \
543  if (!index) { \
544  GET_NEXT_INDEX() \
545  predictor_pair = s->c_predictor_table[index]; \
546  horiz_pred += ((predictor_pair >> 1) * 5); \
547  if (predictor_pair & 1) \
548  GET_NEXT_INDEX() \
549  else \
550  INC_INDEX; \
551  } \
552  } else \
553  INC_INDEX;
554 
555 #define APPLY_C_PREDICTOR_24() \
556  predictor_pair = s->c_predictor_table[index]; \
557  horiz_pred += (predictor_pair >> 1); \
558  if (predictor_pair & 1) { \
559  GET_NEXT_INDEX() \
560  if (!index) { \
561  GET_NEXT_INDEX() \
562  predictor_pair = s->fat_c_predictor_table[index]; \
563  horiz_pred += (predictor_pair >> 1); \
564  if (predictor_pair & 1) \
565  GET_NEXT_INDEX() \
566  else \
567  INC_INDEX; \
568  } \
569  } else \
570  INC_INDEX;
571 
572 
573 #define APPLY_Y_PREDICTOR() \
574  predictor_pair = s->y_predictor_table[index]; \
575  horiz_pred += (predictor_pair >> 1); \
576  if (predictor_pair & 1) { \
577  GET_NEXT_INDEX() \
578  if (!index) { \
579  GET_NEXT_INDEX() \
580  predictor_pair = s->y_predictor_table[index]; \
581  horiz_pred += ((predictor_pair >> 1) * 5); \
582  if (predictor_pair & 1) \
583  GET_NEXT_INDEX() \
584  else \
585  INC_INDEX; \
586  } \
587  } else \
588  INC_INDEX;
589 
590 #define APPLY_Y_PREDICTOR_24() \
591  predictor_pair = s->y_predictor_table[index]; \
592  horiz_pred += (predictor_pair >> 1); \
593  if (predictor_pair & 1) { \
594  GET_NEXT_INDEX() \
595  if (!index) { \
596  GET_NEXT_INDEX() \
597  predictor_pair = s->fat_y_predictor_table[index]; \
598  horiz_pred += (predictor_pair >> 1); \
599  if (predictor_pair & 1) \
600  GET_NEXT_INDEX() \
601  else \
602  INC_INDEX; \
603  } \
604  } else \
605  INC_INDEX;
606 
607 #define OUTPUT_PIXEL_PAIR() \
608  *current_pixel_pair = *vert_pred + horiz_pred; \
609  *vert_pred++ = *current_pixel_pair++;
610 
611 static void truemotion1_decode_16bit(TrueMotion1Context *s)
612 {
613  int y;
614  int pixels_left; /* remaining pixels on this line */
615  unsigned int predictor_pair;
616  unsigned int horiz_pred;
617  unsigned int *vert_pred;
618  unsigned int *current_pixel_pair;
619  unsigned char *current_line = s->frame->data[0];
620  int keyframe = s->flags & FLAG_KEYFRAME;
621 
622  /* these variables are for managing the stream of macroblock change bits */
623  const unsigned char *mb_change_bits = s->mb_change_bits;
624  unsigned char mb_change_byte;
625  unsigned char mb_change_byte_mask;
626  int mb_change_index;
627 
628  /* these variables are for managing the main index stream */
629  int index_stream_index = 0; /* yes, the index into the index stream */
630  int index;
631 
632  /* clean out the line buffer */
633  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
634 
635  GET_NEXT_INDEX();
636 
637  for (y = 0; y < s->avctx->height; y++) {
638 
639  /* re-init variables for the next line iteration */
640  horiz_pred = 0;
641  current_pixel_pair = (unsigned int *)current_line;
642  vert_pred = s->vert_pred;
643  mb_change_index = 0;
644  mb_change_byte = mb_change_bits[mb_change_index++];
645  mb_change_byte_mask = 0x01;
646  pixels_left = s->avctx->width;
647 
648  while (pixels_left > 0) {
649 
650  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
651 
652  switch (y & 3) {
653  case 0:
654  /* if macroblock width is 2, apply C-Y-C-Y; else
655  * apply C-Y-Y */
656  if (s->block_width == 2) {
657  APPLY_C_PREDICTOR();
658  APPLY_Y_PREDICTOR();
659  OUTPUT_PIXEL_PAIR();
660  APPLY_C_PREDICTOR();
661  APPLY_Y_PREDICTOR();
662  OUTPUT_PIXEL_PAIR();
663  } else {
664  APPLY_C_PREDICTOR();
665  APPLY_Y_PREDICTOR();
666  OUTPUT_PIXEL_PAIR();
667  APPLY_Y_PREDICTOR();
668  OUTPUT_PIXEL_PAIR();
669  }
670  break;
671 
672  case 1:
673  case 3:
674  /* always apply 2 Y predictors on these iterations */
675  APPLY_Y_PREDICTOR();
676  OUTPUT_PIXEL_PAIR();
677  APPLY_Y_PREDICTOR();
678  OUTPUT_PIXEL_PAIR();
679  break;
680 
681  case 2:
682  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
683  * depending on the macroblock type */
684  if (s->block_type == BLOCK_2x2) {
685  APPLY_C_PREDICTOR();
686  APPLY_Y_PREDICTOR();
687  OUTPUT_PIXEL_PAIR();
688  APPLY_C_PREDICTOR();
689  APPLY_Y_PREDICTOR();
690  OUTPUT_PIXEL_PAIR();
691  } else if (s->block_type == BLOCK_4x2) {
692  APPLY_C_PREDICTOR();
693  APPLY_Y_PREDICTOR();
694  OUTPUT_PIXEL_PAIR();
695  APPLY_Y_PREDICTOR();
696  OUTPUT_PIXEL_PAIR();
697  } else {
698  APPLY_Y_PREDICTOR();
699  OUTPUT_PIXEL_PAIR();
700  APPLY_Y_PREDICTOR();
701  OUTPUT_PIXEL_PAIR();
702  }
703  break;
704  }
705 
706  } else {
707 
708  /* skip (copy) four pixels, but reassign the horizontal
709  * predictor */
710  *vert_pred++ = *current_pixel_pair++;
711  horiz_pred = *current_pixel_pair - *vert_pred;
712  *vert_pred++ = *current_pixel_pair++;
713 
714  }
715 
716  if (!keyframe) {
717  mb_change_byte_mask <<= 1;
718 
719  /* next byte */
720  if (!mb_change_byte_mask) {
721  mb_change_byte = mb_change_bits[mb_change_index++];
722  mb_change_byte_mask = 0x01;
723  }
724  }
725 
726  pixels_left -= 4;
727  }
728 
729  /* next change row */
730  if (((y + 1) & 3) == 0)
731  mb_change_bits += s->mb_change_bits_row_size;
732 
733  current_line += s->frame->linesize[0];
734  }
735 }
736 
737 static void truemotion1_decode_24bit(TrueMotion1Context *s)
738 {
739  int y;
740  int pixels_left; /* remaining pixels on this line */
741  unsigned int predictor_pair;
742  unsigned int horiz_pred;
743  unsigned int *vert_pred;
744  unsigned int *current_pixel_pair;
745  unsigned char *current_line = s->frame->data[0];
746  int keyframe = s->flags & FLAG_KEYFRAME;
747 
748  /* these variables are for managing the stream of macroblock change bits */
749  const unsigned char *mb_change_bits = s->mb_change_bits;
750  unsigned char mb_change_byte;
751  unsigned char mb_change_byte_mask;
752  int mb_change_index;
753 
754  /* these variables are for managing the main index stream */
755  int index_stream_index = 0; /* yes, the index into the index stream */
756  int index;
757 
758  /* clean out the line buffer */
759  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
760 
761  GET_NEXT_INDEX();
762 
763  for (y = 0; y < s->avctx->height; y++) {
764 
765  /* re-init variables for the next line iteration */
766  horiz_pred = 0;
767  current_pixel_pair = (unsigned int *)current_line;
768  vert_pred = s->vert_pred;
769  mb_change_index = 0;
770  mb_change_byte = mb_change_bits[mb_change_index++];
771  mb_change_byte_mask = 0x01;
772  pixels_left = s->avctx->width;
773 
774  while (pixels_left > 0) {
775 
776  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
777 
778  switch (y & 3) {
779  case 0:
780  /* if macroblock width is 2, apply C-Y-C-Y; else
781  * apply C-Y-Y */
782  if (s->block_width == 2) {
783  APPLY_C_PREDICTOR_24();
784  APPLY_Y_PREDICTOR_24();
785  OUTPUT_PIXEL_PAIR();
786  APPLY_C_PREDICTOR_24();
787  APPLY_Y_PREDICTOR_24();
788  OUTPUT_PIXEL_PAIR();
789  } else {
790  APPLY_C_PREDICTOR_24();
791  APPLY_Y_PREDICTOR_24();
792  OUTPUT_PIXEL_PAIR();
793  APPLY_Y_PREDICTOR_24();
794  OUTPUT_PIXEL_PAIR();
795  }
796  break;
797 
798  case 1:
799  case 3:
800  /* always apply 2 Y predictors on these iterations */
801  APPLY_Y_PREDICTOR_24();
802  OUTPUT_PIXEL_PAIR();
803  APPLY_Y_PREDICTOR_24();
804  OUTPUT_PIXEL_PAIR();
805  break;
806 
807  case 2:
808  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
809  * depending on the macroblock type */
810  if (s->block_type == BLOCK_2x2) {
811  APPLY_C_PREDICTOR_24();
812  APPLY_Y_PREDICTOR_24();
813  OUTPUT_PIXEL_PAIR();
814  APPLY_C_PREDICTOR_24();
815  APPLY_Y_PREDICTOR_24();
816  OUTPUT_PIXEL_PAIR();
817  } else if (s->block_type == BLOCK_4x2) {
818  APPLY_C_PREDICTOR_24();
819  APPLY_Y_PREDICTOR_24();
820  OUTPUT_PIXEL_PAIR();
821  APPLY_Y_PREDICTOR_24();
822  OUTPUT_PIXEL_PAIR();
823  } else {
824  APPLY_Y_PREDICTOR_24();
825  OUTPUT_PIXEL_PAIR();
826  APPLY_Y_PREDICTOR_24();
827  OUTPUT_PIXEL_PAIR();
828  }
829  break;
830  }
831 
832  } else {
833 
834  /* skip (copy) four pixels, but reassign the horizontal
835  * predictor */
836  *vert_pred++ = *current_pixel_pair++;
837  horiz_pred = *current_pixel_pair - *vert_pred;
838  *vert_pred++ = *current_pixel_pair++;
839 
840  }
841 
842  if (!keyframe) {
843  mb_change_byte_mask <<= 1;
844 
845  /* next byte */
846  if (!mb_change_byte_mask) {
847  mb_change_byte = mb_change_bits[mb_change_index++];
848  mb_change_byte_mask = 0x01;
849  }
850  }
851 
852  pixels_left -= 2;
853  }
854 
855  /* next change row */
856  if (((y + 1) & 3) == 0)
857  mb_change_bits += s->mb_change_bits_row_size;
858 
859  current_line += s->frame->linesize[0];
860  }
861 }
862 
863 
864 static int truemotion1_decode_frame(AVCodecContext *avctx,
865  void *data, int *got_frame,
866  AVPacket *avpkt)
867 {
868  const uint8_t *buf = avpkt->data;
869  int ret, buf_size = avpkt->size;
870  TrueMotion1Context *s = avctx->priv_data;
871 
872  s->buf = buf;
873  s->size = buf_size;
874 
875  if ((ret = truemotion1_decode_header(s)) < 0)
876  return ret;
877 
878  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
879  return ret;
880 
881  if (compression_types[s->compression].algorithm == ALGO_RGB24H) {
882  truemotion1_decode_24bit(s);
883  } else if (compression_types[s->compression].algorithm != ALGO_NOP) {
884  truemotion1_decode_16bit(s);
885  }
886 
887  if ((ret = av_frame_ref(data, s->frame)) < 0)
888  return ret;
889 
890  *got_frame = 1;
891 
892  /* report that the buffer was completely consumed */
893  return buf_size;
894 }
895 
896 static av_cold int truemotion1_decode_end(AVCodecContext *avctx)
897 {
898  TrueMotion1Context *s = avctx->priv_data;
899 
900  av_frame_free(&s->frame);
901  av_freep(&s->vert_pred);
902 
903  return 0;
904 }
905 
906 AVCodec ff_truemotion1_decoder = {
907  .name = "truemotion1",
908  .long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 1.0"),
909  .type = AVMEDIA_TYPE_VIDEO,
910  .id = AV_CODEC_ID_TRUEMOTION1,
911  .priv_data_size = sizeof(TrueMotion1Context),
912  .init = truemotion1_decode_init,
913  .close = truemotion1_decode_end,
914  .decode = truemotion1_decode_frame,
915  .capabilities = CODEC_CAP_DR1,
916 };
Generated on Wed Jul 23 2014 19:21:10 for FFmpeg by   doxygen 1.8.2