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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 || header.header_size >= s->size)
321  {
322  av_log(s->avctx, AV_LOG_ERROR, "invalid header size (%d)\n", s->buf[0]);
323  return AVERROR_INVALIDDATA;
324  }
325 
326  /* unscramble the header bytes with a XOR operation */
327  for (i = 1; i < header.header_size; i++)
328  header_buffer[i - 1] = s->buf[i] ^ s->buf[i + 1];
329 
330  header.compression = header_buffer[0];
331  header.deltaset = header_buffer[1];
332  header.vectable = header_buffer[2];
333  header.ysize = AV_RL16(&header_buffer[3]);
334  header.xsize = AV_RL16(&header_buffer[5]);
335  header.checksum = AV_RL16(&header_buffer[7]);
336  header.version = header_buffer[9];
337  header.header_type = header_buffer[10];
338  header.flags = header_buffer[11];
339  header.control = header_buffer[12];
340 
341  /* Version 2 */
342  if (header.version >= 2)
343  {
344  if (header.header_type > 3)
345  {
346  av_log(s->avctx, AV_LOG_ERROR, "invalid header type (%d)\n", header.header_type);
347  return AVERROR_INVALIDDATA;
348  } else if ((header.header_type == 2) || (header.header_type == 3)) {
349  s->flags = header.flags;
350  if (!(s->flags & FLAG_INTERFRAME))
351  s->flags |= FLAG_KEYFRAME;
352  } else
353  s->flags = FLAG_KEYFRAME;
354  } else /* Version 1 */
355  s->flags = FLAG_KEYFRAME;
356 
357  if (s->flags & FLAG_SPRITE) {
358  avpriv_request_sample(s->avctx, "Frame with sprite");
359  /* FIXME header.width, height, xoffset and yoffset aren't initialized */
360  return AVERROR_PATCHWELCOME;
361  } else {
362  s->w = header.xsize;
363  s->h = header.ysize;
364  if (header.header_type < 2) {
365  if ((s->w < 213) && (s->h >= 176))
366  {
367  s->flags |= FLAG_INTERPOLATED;
368  avpriv_request_sample(s->avctx, "Interpolated frame");
369  }
370  }
371  }
372 
373  if (header.compression >= 17) {
374  av_log(s->avctx, AV_LOG_ERROR, "invalid compression type (%d)\n", header.compression);
375  return AVERROR_INVALIDDATA;
376  }
377 
378  if ((header.deltaset != s->last_deltaset) ||
379  (header.vectable != s->last_vectable))
380  select_delta_tables(s, header.deltaset);
381 
382  if ((header.compression & 1) && header.header_type)
383  sel_vector_table = pc_tbl2;
384  else {
385  if (header.vectable > 0 && header.vectable < 4)
386  sel_vector_table = tables[header.vectable - 1];
387  else {
388  av_log(s->avctx, AV_LOG_ERROR, "invalid vector table id (%d)\n", header.vectable);
389  return AVERROR_INVALIDDATA;
390  }
391  }
392 
393  if (compression_types[header.compression].algorithm == ALGO_RGB24H) {
394  new_pix_fmt = AV_PIX_FMT_RGB32;
395  width_shift = 1;
396  } else
397  new_pix_fmt = AV_PIX_FMT_RGB555; // RGB565 is supported as well
398 
399  s->w >>= width_shift;
400  if ((ret = av_image_check_size(s->w, s->h, 0, s->avctx)) < 0)
401  return ret;
402 
403  if (s->w != s->avctx->width || s->h != s->avctx->height ||
404  new_pix_fmt != s->avctx->pix_fmt) {
405  av_frame_unref(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  if (!s->vert_pred)
411  return AVERROR(ENOMEM);
412  }
413 
414  /* There is 1 change bit per 4 pixels, so each change byte represents
415  * 32 pixels; divide width by 4 to obtain the number of change bits and
416  * then round up to the nearest byte. */
417  s->mb_change_bits_row_size = ((s->avctx->width >> (2 - width_shift)) + 7) >> 3;
418 
419  if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
420  {
421  if (compression_types[header.compression].algorithm == ALGO_RGB24H)
422  gen_vector_table24(s, sel_vector_table);
423  else
424  if (s->avctx->pix_fmt == AV_PIX_FMT_RGB555)
425  gen_vector_table15(s, sel_vector_table);
426  else
427  gen_vector_table16(s, sel_vector_table);
428  }
429 
430  /* set up pointers to the other key data chunks */
431  s->mb_change_bits = s->buf + header.header_size;
432  if (s->flags & FLAG_KEYFRAME) {
433  /* no change bits specified for a keyframe; only index bytes */
434  s->index_stream = s->mb_change_bits;
435  } else {
436  /* one change bit per 4x4 block */
437  s->index_stream = s->mb_change_bits +
438  (s->mb_change_bits_row_size * (s->avctx->height >> 2));
439  }
440  s->index_stream_size = s->size - (s->index_stream - s->buf);
441 
442  s->last_deltaset = header.deltaset;
443  s->last_vectable = header.vectable;
444  s->compression = header.compression;
445  s->block_width = compression_types[header.compression].block_width;
446  s->block_height = compression_types[header.compression].block_height;
447  s->block_type = compression_types[header.compression].block_type;
448 
449  if (s->avctx->debug & FF_DEBUG_PICT_INFO)
450  av_log(s->avctx, AV_LOG_INFO, "tables: %d / %d c:%d %dx%d t:%d %s%s%s%s\n",
451  s->last_deltaset, s->last_vectable, s->compression, s->block_width,
452  s->block_height, s->block_type,
453  s->flags & FLAG_KEYFRAME ? " KEY" : "",
454  s->flags & FLAG_INTERFRAME ? " INTER" : "",
455  s->flags & FLAG_SPRITE ? " SPRITE" : "",
456  s->flags & FLAG_INTERPOLATED ? " INTERPOL" : "");
457 
458  return header.header_size;
459 }
460 
461 static av_cold int truemotion1_decode_init(AVCodecContext *avctx)
462 {
463  TrueMotion1Context *s = avctx->priv_data;
464 
465  s->avctx = avctx;
466 
467  // FIXME: it may change ?
468 // if (avctx->bits_per_sample == 24)
469 // avctx->pix_fmt = AV_PIX_FMT_RGB24;
470 // else
471 // avctx->pix_fmt = AV_PIX_FMT_RGB555;
472 
473  s->frame = av_frame_alloc();
474  if (!s->frame)
475  return AVERROR(ENOMEM);
476 
477  /* there is a vertical predictor for each pixel in a line; each vertical
478  * predictor is 0 to start with */
479  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
480  if (!s->vert_pred)
481  return AVERROR(ENOMEM);
482 
483  return 0;
484 }
485 
486 /*
487 Block decoding order:
488 
489 dxi: Y-Y
490 dxic: Y-C-Y
491 dxic2: Y-C-Y-C
492 
493 hres,vres,i,i%vres (0 < i < 4)
494 2x2 0: 0 dxic2
495 2x2 1: 1 dxi
496 2x2 2: 0 dxic2
497 2x2 3: 1 dxi
498 2x4 0: 0 dxic2
499 2x4 1: 1 dxi
500 2x4 2: 2 dxi
501 2x4 3: 3 dxi
502 4x2 0: 0 dxic
503 4x2 1: 1 dxi
504 4x2 2: 0 dxic
505 4x2 3: 1 dxi
506 4x4 0: 0 dxic
507 4x4 1: 1 dxi
508 4x4 2: 2 dxi
509 4x4 3: 3 dxi
510 */
511 
512 #define GET_NEXT_INDEX() \
513 {\
514  if (index_stream_index >= s->index_stream_size) { \
515  av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
516  return; \
517  } \
518  index = s->index_stream[index_stream_index++] * 4; \
519 }
520 
521 #define APPLY_C_PREDICTOR() \
522  if(index > 1023){\
523  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
524  return; \
525  }\
526  predictor_pair = s->c_predictor_table[index]; \
527  horiz_pred += (predictor_pair >> 1); \
528  if (predictor_pair & 1) { \
529  GET_NEXT_INDEX() \
530  if (!index) { \
531  GET_NEXT_INDEX() \
532  predictor_pair = s->c_predictor_table[index]; \
533  horiz_pred += ((predictor_pair >> 1) * 5); \
534  if (predictor_pair & 1) \
535  GET_NEXT_INDEX() \
536  else \
537  index++; \
538  } \
539  } else \
540  index++;
541 
542 #define APPLY_C_PREDICTOR_24() \
543  if(index > 1023){\
544  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
545  return; \
546  }\
547  predictor_pair = s->c_predictor_table[index]; \
548  horiz_pred += (predictor_pair >> 1); \
549  if (predictor_pair & 1) { \
550  GET_NEXT_INDEX() \
551  if (!index) { \
552  GET_NEXT_INDEX() \
553  predictor_pair = s->fat_c_predictor_table[index]; \
554  horiz_pred += (predictor_pair >> 1); \
555  if (predictor_pair & 1) \
556  GET_NEXT_INDEX() \
557  else \
558  index++; \
559  } \
560  } else \
561  index++;
562 
563 
564 #define APPLY_Y_PREDICTOR() \
565  if(index > 1023){\
566  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
567  return; \
568  }\
569  predictor_pair = s->y_predictor_table[index]; \
570  horiz_pred += (predictor_pair >> 1); \
571  if (predictor_pair & 1) { \
572  GET_NEXT_INDEX() \
573  if (!index) { \
574  GET_NEXT_INDEX() \
575  predictor_pair = s->y_predictor_table[index]; \
576  horiz_pred += ((predictor_pair >> 1) * 5); \
577  if (predictor_pair & 1) \
578  GET_NEXT_INDEX() \
579  else \
580  index++; \
581  } \
582  } else \
583  index++;
584 
585 #define APPLY_Y_PREDICTOR_24() \
586  if(index > 1023){\
587  av_log(s->avctx, AV_LOG_ERROR, " index %d went out of bounds\n", index); \
588  return; \
589  }\
590  predictor_pair = s->y_predictor_table[index]; \
591  horiz_pred += (predictor_pair >> 1); \
592  if (predictor_pair & 1) { \
593  GET_NEXT_INDEX() \
594  if (!index) { \
595  GET_NEXT_INDEX() \
596  predictor_pair = s->fat_y_predictor_table[index]; \
597  horiz_pred += (predictor_pair >> 1); \
598  if (predictor_pair & 1) \
599  GET_NEXT_INDEX() \
600  else \
601  index++; \
602  } \
603  } else \
604  index++;
605 
606 #define OUTPUT_PIXEL_PAIR() \
607  *current_pixel_pair = *vert_pred + horiz_pred; \
608  *vert_pred++ = *current_pixel_pair++;
609 
610 static void truemotion1_decode_16bit(TrueMotion1Context *s)
611 {
612  int y;
613  int pixels_left; /* remaining pixels on this line */
614  unsigned int predictor_pair;
615  unsigned int horiz_pred;
616  unsigned int *vert_pred;
617  unsigned int *current_pixel_pair;
618  unsigned char *current_line = s->frame->data[0];
619  int keyframe = s->flags & FLAG_KEYFRAME;
620 
621  /* these variables are for managing the stream of macroblock change bits */
622  const unsigned char *mb_change_bits = s->mb_change_bits;
623  unsigned char mb_change_byte;
624  unsigned char mb_change_byte_mask;
625  int mb_change_index;
626 
627  /* these variables are for managing the main index stream */
628  int index_stream_index = 0; /* yes, the index into the index stream */
629  int index;
630 
631  /* clean out the line buffer */
632  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
633 
634  GET_NEXT_INDEX();
635 
636  for (y = 0; y < s->avctx->height; y++) {
637 
638  /* re-init variables for the next line iteration */
639  horiz_pred = 0;
640  current_pixel_pair = (unsigned int *)current_line;
641  vert_pred = s->vert_pred;
642  mb_change_index = 0;
643  mb_change_byte = mb_change_bits[mb_change_index++];
644  mb_change_byte_mask = 0x01;
645  pixels_left = s->avctx->width;
646 
647  while (pixels_left > 0) {
648 
649  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
650 
651  switch (y & 3) {
652  case 0:
653  /* if macroblock width is 2, apply C-Y-C-Y; else
654  * apply C-Y-Y */
655  if (s->block_width == 2) {
656  APPLY_C_PREDICTOR();
657  APPLY_Y_PREDICTOR();
658  OUTPUT_PIXEL_PAIR();
659  APPLY_C_PREDICTOR();
660  APPLY_Y_PREDICTOR();
661  OUTPUT_PIXEL_PAIR();
662  } else {
663  APPLY_C_PREDICTOR();
664  APPLY_Y_PREDICTOR();
665  OUTPUT_PIXEL_PAIR();
666  APPLY_Y_PREDICTOR();
667  OUTPUT_PIXEL_PAIR();
668  }
669  break;
670 
671  case 1:
672  case 3:
673  /* always apply 2 Y predictors on these iterations */
674  APPLY_Y_PREDICTOR();
675  OUTPUT_PIXEL_PAIR();
676  APPLY_Y_PREDICTOR();
677  OUTPUT_PIXEL_PAIR();
678  break;
679 
680  case 2:
681  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
682  * depending on the macroblock type */
683  if (s->block_type == BLOCK_2x2) {
684  APPLY_C_PREDICTOR();
685  APPLY_Y_PREDICTOR();
686  OUTPUT_PIXEL_PAIR();
687  APPLY_C_PREDICTOR();
688  APPLY_Y_PREDICTOR();
689  OUTPUT_PIXEL_PAIR();
690  } else if (s->block_type == BLOCK_4x2) {
691  APPLY_C_PREDICTOR();
692  APPLY_Y_PREDICTOR();
693  OUTPUT_PIXEL_PAIR();
694  APPLY_Y_PREDICTOR();
695  OUTPUT_PIXEL_PAIR();
696  } else {
697  APPLY_Y_PREDICTOR();
698  OUTPUT_PIXEL_PAIR();
699  APPLY_Y_PREDICTOR();
700  OUTPUT_PIXEL_PAIR();
701  }
702  break;
703  }
704 
705  } else {
706 
707  /* skip (copy) four pixels, but reassign the horizontal
708  * predictor */
709  *vert_pred++ = *current_pixel_pair++;
710  horiz_pred = *current_pixel_pair - *vert_pred;
711  *vert_pred++ = *current_pixel_pair++;
712 
713  }
714 
715  if (!keyframe) {
716  mb_change_byte_mask <<= 1;
717 
718  /* next byte */
719  if (!mb_change_byte_mask) {
720  mb_change_byte = mb_change_bits[mb_change_index++];
721  mb_change_byte_mask = 0x01;
722  }
723  }
724 
725  pixels_left -= 4;
726  }
727 
728  /* next change row */
729  if (((y + 1) & 3) == 0)
730  mb_change_bits += s->mb_change_bits_row_size;
731 
732  current_line += s->frame->linesize[0];
733  }
734 }
735 
736 static void truemotion1_decode_24bit(TrueMotion1Context *s)
737 {
738  int y;
739  int pixels_left; /* remaining pixels on this line */
740  unsigned int predictor_pair;
741  unsigned int horiz_pred;
742  unsigned int *vert_pred;
743  unsigned int *current_pixel_pair;
744  unsigned char *current_line = s->frame->data[0];
745  int keyframe = s->flags & FLAG_KEYFRAME;
746 
747  /* these variables are for managing the stream of macroblock change bits */
748  const unsigned char *mb_change_bits = s->mb_change_bits;
749  unsigned char mb_change_byte;
750  unsigned char mb_change_byte_mask;
751  int mb_change_index;
752 
753  /* these variables are for managing the main index stream */
754  int index_stream_index = 0; /* yes, the index into the index stream */
755  int index;
756 
757  /* clean out the line buffer */
758  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
759 
760  GET_NEXT_INDEX();
761 
762  for (y = 0; y < s->avctx->height; y++) {
763 
764  /* re-init variables for the next line iteration */
765  horiz_pred = 0;
766  current_pixel_pair = (unsigned int *)current_line;
767  vert_pred = s->vert_pred;
768  mb_change_index = 0;
769  mb_change_byte = mb_change_bits[mb_change_index++];
770  mb_change_byte_mask = 0x01;
771  pixels_left = s->avctx->width;
772 
773  while (pixels_left > 0) {
774 
775  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
776 
777  switch (y & 3) {
778  case 0:
779  /* if macroblock width is 2, apply C-Y-C-Y; else
780  * apply C-Y-Y */
781  if (s->block_width == 2) {
782  APPLY_C_PREDICTOR_24();
783  APPLY_Y_PREDICTOR_24();
784  OUTPUT_PIXEL_PAIR();
785  APPLY_C_PREDICTOR_24();
786  APPLY_Y_PREDICTOR_24();
787  OUTPUT_PIXEL_PAIR();
788  } else {
789  APPLY_C_PREDICTOR_24();
790  APPLY_Y_PREDICTOR_24();
791  OUTPUT_PIXEL_PAIR();
792  APPLY_Y_PREDICTOR_24();
793  OUTPUT_PIXEL_PAIR();
794  }
795  break;
796 
797  case 1:
798  case 3:
799  /* always apply 2 Y predictors on these iterations */
800  APPLY_Y_PREDICTOR_24();
801  OUTPUT_PIXEL_PAIR();
802  APPLY_Y_PREDICTOR_24();
803  OUTPUT_PIXEL_PAIR();
804  break;
805 
806  case 2:
807  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
808  * depending on the macroblock type */
809  if (s->block_type == BLOCK_2x2) {
810  APPLY_C_PREDICTOR_24();
811  APPLY_Y_PREDICTOR_24();
812  OUTPUT_PIXEL_PAIR();
813  APPLY_C_PREDICTOR_24();
814  APPLY_Y_PREDICTOR_24();
815  OUTPUT_PIXEL_PAIR();
816  } else if (s->block_type == BLOCK_4x2) {
817  APPLY_C_PREDICTOR_24();
818  APPLY_Y_PREDICTOR_24();
819  OUTPUT_PIXEL_PAIR();
820  APPLY_Y_PREDICTOR_24();
821  OUTPUT_PIXEL_PAIR();
822  } else {
823  APPLY_Y_PREDICTOR_24();
824  OUTPUT_PIXEL_PAIR();
825  APPLY_Y_PREDICTOR_24();
826  OUTPUT_PIXEL_PAIR();
827  }
828  break;
829  }
830 
831  } else {
832 
833  /* skip (copy) four pixels, but reassign the horizontal
834  * predictor */
835  *vert_pred++ = *current_pixel_pair++;
836  horiz_pred = *current_pixel_pair - *vert_pred;
837  *vert_pred++ = *current_pixel_pair++;
838 
839  }
840 
841  if (!keyframe) {
842  mb_change_byte_mask <<= 1;
843 
844  /* next byte */
845  if (!mb_change_byte_mask) {
846  mb_change_byte = mb_change_bits[mb_change_index++];
847  mb_change_byte_mask = 0x01;
848  }
849  }
850 
851  pixels_left -= 2;
852  }
853 
854  /* next change row */
855  if (((y + 1) & 3) == 0)
856  mb_change_bits += s->mb_change_bits_row_size;
857 
858  current_line += s->frame->linesize[0];
859  }
860 }
861 
862 
863 static int truemotion1_decode_frame(AVCodecContext *avctx,
864  void *data, int *got_frame,
865  AVPacket *avpkt)
866 {
867  const uint8_t *buf = avpkt->data;
868  int ret, buf_size = avpkt->size;
869  TrueMotion1Context *s = avctx->priv_data;
870 
871  s->buf = buf;
872  s->size = buf_size;
873 
874  if ((ret = truemotion1_decode_header(s)) < 0)
875  return ret;
876 
877  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
878  return ret;
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  if ((ret = av_frame_ref(data, s->frame)) < 0)
887  return ret;
888 
889  *got_frame = 1;
890 
891  /* report that the buffer was completely consumed */
892  return buf_size;
893 }
894 
895 static av_cold int truemotion1_decode_end(AVCodecContext *avctx)
896 {
897  TrueMotion1Context *s = avctx->priv_data;
898 
899  av_frame_free(&s->frame);
900  av_freep(&s->vert_pred);
901 
902  return 0;
903 }
904 
905 AVCodec ff_truemotion1_decoder = {
906  .name = "truemotion1",
907  .long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 1.0"),
908  .type = AVMEDIA_TYPE_VIDEO,
909  .id = AV_CODEC_ID_TRUEMOTION1,
910  .priv_data_size = sizeof(TrueMotion1Context),
911  .init = truemotion1_decode_init,
912  .close = truemotion1_decode_end,
913  .decode = truemotion1_decode_frame,
914  .capabilities = CODEC_CAP_DR1,
915 };
Generated on Sat Jan 25 2014 19:51:55 for FFmpeg by   doxygen 1.8.2