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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 
401  if (s->w != s->avctx->width || s->h != s->avctx->height ||
402  new_pix_fmt != s->avctx->pix_fmt) {
403  av_frame_unref(s->frame);
404  s->avctx->sample_aspect_ratio = (AVRational){ 1 << width_shift, 1 };
405  s->avctx->pix_fmt = new_pix_fmt;
406 
407  if ((ret = ff_set_dimensions(s->avctx, s->w, s->h)) < 0)
408  return ret;
409 
410  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
411  if (!s->vert_pred)
412  return AVERROR(ENOMEM);
413  }
414 
415  /* There is 1 change bit per 4 pixels, so each change byte represents
416  * 32 pixels; divide width by 4 to obtain the number of change bits and
417  * then round up to the nearest byte. */
418  s->mb_change_bits_row_size = ((s->avctx->width >> (2 - width_shift)) + 7) >> 3;
419 
420  if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
421  {
422  if (compression_types[header.compression].algorithm == ALGO_RGB24H)
423  gen_vector_table24(s, sel_vector_table);
424  else
425  if (s->avctx->pix_fmt == AV_PIX_FMT_RGB555)
426  gen_vector_table15(s, sel_vector_table);
427  else
428  gen_vector_table16(s, sel_vector_table);
429  }
430 
431  /* set up pointers to the other key data chunks */
432  s->mb_change_bits = s->buf + header.header_size;
433  if (s->flags & FLAG_KEYFRAME) {
434  /* no change bits specified for a keyframe; only index bytes */
435  s->index_stream = s->mb_change_bits;
436  } else {
437  /* one change bit per 4x4 block */
438  s->index_stream = s->mb_change_bits +
439  (s->mb_change_bits_row_size * (s->avctx->height >> 2));
440  }
441  s->index_stream_size = s->size - (s->index_stream - s->buf);
442 
443  s->last_deltaset = header.deltaset;
444  s->last_vectable = header.vectable;
445  s->compression = header.compression;
446  s->block_width = compression_types[header.compression].block_width;
447  s->block_height = compression_types[header.compression].block_height;
448  s->block_type = compression_types[header.compression].block_type;
449 
450  if (s->avctx->debug & FF_DEBUG_PICT_INFO)
451  av_log(s->avctx, AV_LOG_INFO, "tables: %d / %d c:%d %dx%d t:%d %s%s%s%s\n",
452  s->last_deltaset, s->last_vectable, s->compression, s->block_width,
453  s->block_height, s->block_type,
454  s->flags & FLAG_KEYFRAME ? " KEY" : "",
455  s->flags & FLAG_INTERFRAME ? " INTER" : "",
456  s->flags & FLAG_SPRITE ? " SPRITE" : "",
457  s->flags & FLAG_INTERPOLATED ? " INTERPOL" : "");
458 
459  return header.header_size;
460 }
461 
462 static av_cold int truemotion1_decode_init(AVCodecContext *avctx)
463 {
464  TrueMotion1Context *s = avctx->priv_data;
465 
466  s->avctx = avctx;
467 
468  // FIXME: it may change ?
469 // if (avctx->bits_per_sample == 24)
470 // avctx->pix_fmt = AV_PIX_FMT_RGB24;
471 // else
472 // avctx->pix_fmt = AV_PIX_FMT_RGB555;
473 
474  s->frame = av_frame_alloc();
475  if (!s->frame)
476  return AVERROR(ENOMEM);
477 
478  /* there is a vertical predictor for each pixel in a line; each vertical
479  * predictor is 0 to start with */
480  av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
481  if (!s->vert_pred)
482  return AVERROR(ENOMEM);
483 
484  return 0;
485 }
486 
487 /*
488 Block decoding order:
489 
490 dxi: Y-Y
491 dxic: Y-C-Y
492 dxic2: Y-C-Y-C
493 
494 hres,vres,i,i%vres (0 < i < 4)
495 2x2 0: 0 dxic2
496 2x2 1: 1 dxi
497 2x2 2: 0 dxic2
498 2x2 3: 1 dxi
499 2x4 0: 0 dxic2
500 2x4 1: 1 dxi
501 2x4 2: 2 dxi
502 2x4 3: 3 dxi
503 4x2 0: 0 dxic
504 4x2 1: 1 dxi
505 4x2 2: 0 dxic
506 4x2 3: 1 dxi
507 4x4 0: 0 dxic
508 4x4 1: 1 dxi
509 4x4 2: 2 dxi
510 4x4 3: 3 dxi
511 */
512 
513 #define GET_NEXT_INDEX() \
514 {\
515  if (index_stream_index >= s->index_stream_size) { \
516  av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
517  return; \
518  } \
519  index = s->index_stream[index_stream_index++] * 4; \
520 }
521 
522 #define INC_INDEX \
523 do { \
524  if (index >= 1023) { \
525  av_log(s->avctx, AV_LOG_ERROR, "Invalid index value.\n"); \
526  return; \
527  } \
528  index++; \
529 } while (0)
530 
531 #define APPLY_C_PREDICTOR() \
532  predictor_pair = s->c_predictor_table[index]; \
533  horiz_pred += (predictor_pair >> 1); \
534  if (predictor_pair & 1) { \
535  GET_NEXT_INDEX() \
536  if (!index) { \
537  GET_NEXT_INDEX() \
538  predictor_pair = s->c_predictor_table[index]; \
539  horiz_pred += ((predictor_pair >> 1) * 5); \
540  if (predictor_pair & 1) \
541  GET_NEXT_INDEX() \
542  else \
543  INC_INDEX; \
544  } \
545  } else \
546  INC_INDEX;
547 
548 #define APPLY_C_PREDICTOR_24() \
549  predictor_pair = s->c_predictor_table[index]; \
550  horiz_pred += (predictor_pair >> 1); \
551  if (predictor_pair & 1) { \
552  GET_NEXT_INDEX() \
553  if (!index) { \
554  GET_NEXT_INDEX() \
555  predictor_pair = s->fat_c_predictor_table[index]; \
556  horiz_pred += (predictor_pair >> 1); \
557  if (predictor_pair & 1) \
558  GET_NEXT_INDEX() \
559  else \
560  INC_INDEX; \
561  } \
562  } else \
563  INC_INDEX;
564 
565 
566 #define APPLY_Y_PREDICTOR() \
567  predictor_pair = s->y_predictor_table[index]; \
568  horiz_pred += (predictor_pair >> 1); \
569  if (predictor_pair & 1) { \
570  GET_NEXT_INDEX() \
571  if (!index) { \
572  GET_NEXT_INDEX() \
573  predictor_pair = s->y_predictor_table[index]; \
574  horiz_pred += ((predictor_pair >> 1) * 5); \
575  if (predictor_pair & 1) \
576  GET_NEXT_INDEX() \
577  else \
578  INC_INDEX; \
579  } \
580  } else \
581  INC_INDEX;
582 
583 #define APPLY_Y_PREDICTOR_24() \
584  predictor_pair = s->y_predictor_table[index]; \
585  horiz_pred += (predictor_pair >> 1); \
586  if (predictor_pair & 1) { \
587  GET_NEXT_INDEX() \
588  if (!index) { \
589  GET_NEXT_INDEX() \
590  predictor_pair = s->fat_y_predictor_table[index]; \
591  horiz_pred += (predictor_pair >> 1); \
592  if (predictor_pair & 1) \
593  GET_NEXT_INDEX() \
594  else \
595  INC_INDEX; \
596  } \
597  } else \
598  INC_INDEX;
599 
600 #define OUTPUT_PIXEL_PAIR() \
601  *current_pixel_pair = *vert_pred + horiz_pred; \
602  *vert_pred++ = *current_pixel_pair++;
603 
604 static void truemotion1_decode_16bit(TrueMotion1Context *s)
605 {
606  int y;
607  int pixels_left; /* remaining pixels on this line */
608  unsigned int predictor_pair;
609  unsigned int horiz_pred;
610  unsigned int *vert_pred;
611  unsigned int *current_pixel_pair;
612  unsigned char *current_line = s->frame->data[0];
613  int keyframe = s->flags & FLAG_KEYFRAME;
614 
615  /* these variables are for managing the stream of macroblock change bits */
616  const unsigned char *mb_change_bits = s->mb_change_bits;
617  unsigned char mb_change_byte;
618  unsigned char mb_change_byte_mask;
619  int mb_change_index;
620 
621  /* these variables are for managing the main index stream */
622  int index_stream_index = 0; /* yes, the index into the index stream */
623  int index;
624 
625  /* clean out the line buffer */
626  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
627 
628  GET_NEXT_INDEX();
629 
630  for (y = 0; y < s->avctx->height; y++) {
631 
632  /* re-init variables for the next line iteration */
633  horiz_pred = 0;
634  current_pixel_pair = (unsigned int *)current_line;
635  vert_pred = s->vert_pred;
636  mb_change_index = 0;
637  mb_change_byte = mb_change_bits[mb_change_index++];
638  mb_change_byte_mask = 0x01;
639  pixels_left = s->avctx->width;
640 
641  while (pixels_left > 0) {
642 
643  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
644 
645  switch (y & 3) {
646  case 0:
647  /* if macroblock width is 2, apply C-Y-C-Y; else
648  * apply C-Y-Y */
649  if (s->block_width == 2) {
650  APPLY_C_PREDICTOR();
651  APPLY_Y_PREDICTOR();
652  OUTPUT_PIXEL_PAIR();
653  APPLY_C_PREDICTOR();
654  APPLY_Y_PREDICTOR();
655  OUTPUT_PIXEL_PAIR();
656  } else {
657  APPLY_C_PREDICTOR();
658  APPLY_Y_PREDICTOR();
659  OUTPUT_PIXEL_PAIR();
660  APPLY_Y_PREDICTOR();
661  OUTPUT_PIXEL_PAIR();
662  }
663  break;
664 
665  case 1:
666  case 3:
667  /* always apply 2 Y predictors on these iterations */
668  APPLY_Y_PREDICTOR();
669  OUTPUT_PIXEL_PAIR();
670  APPLY_Y_PREDICTOR();
671  OUTPUT_PIXEL_PAIR();
672  break;
673 
674  case 2:
675  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
676  * depending on the macroblock type */
677  if (s->block_type == BLOCK_2x2) {
678  APPLY_C_PREDICTOR();
679  APPLY_Y_PREDICTOR();
680  OUTPUT_PIXEL_PAIR();
681  APPLY_C_PREDICTOR();
682  APPLY_Y_PREDICTOR();
683  OUTPUT_PIXEL_PAIR();
684  } else if (s->block_type == BLOCK_4x2) {
685  APPLY_C_PREDICTOR();
686  APPLY_Y_PREDICTOR();
687  OUTPUT_PIXEL_PAIR();
688  APPLY_Y_PREDICTOR();
689  OUTPUT_PIXEL_PAIR();
690  } else {
691  APPLY_Y_PREDICTOR();
692  OUTPUT_PIXEL_PAIR();
693  APPLY_Y_PREDICTOR();
694  OUTPUT_PIXEL_PAIR();
695  }
696  break;
697  }
698 
699  } else {
700 
701  /* skip (copy) four pixels, but reassign the horizontal
702  * predictor */
703  *vert_pred++ = *current_pixel_pair++;
704  horiz_pred = *current_pixel_pair - *vert_pred;
705  *vert_pred++ = *current_pixel_pair++;
706 
707  }
708 
709  if (!keyframe) {
710  mb_change_byte_mask <<= 1;
711 
712  /* next byte */
713  if (!mb_change_byte_mask) {
714  mb_change_byte = mb_change_bits[mb_change_index++];
715  mb_change_byte_mask = 0x01;
716  }
717  }
718 
719  pixels_left -= 4;
720  }
721 
722  /* next change row */
723  if (((y + 1) & 3) == 0)
724  mb_change_bits += s->mb_change_bits_row_size;
725 
726  current_line += s->frame->linesize[0];
727  }
728 }
729 
730 static void truemotion1_decode_24bit(TrueMotion1Context *s)
731 {
732  int y;
733  int pixels_left; /* remaining pixels on this line */
734  unsigned int predictor_pair;
735  unsigned int horiz_pred;
736  unsigned int *vert_pred;
737  unsigned int *current_pixel_pair;
738  unsigned char *current_line = s->frame->data[0];
739  int keyframe = s->flags & FLAG_KEYFRAME;
740 
741  /* these variables are for managing the stream of macroblock change bits */
742  const unsigned char *mb_change_bits = s->mb_change_bits;
743  unsigned char mb_change_byte;
744  unsigned char mb_change_byte_mask;
745  int mb_change_index;
746 
747  /* these variables are for managing the main index stream */
748  int index_stream_index = 0; /* yes, the index into the index stream */
749  int index;
750 
751  /* clean out the line buffer */
752  memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
753 
754  GET_NEXT_INDEX();
755 
756  for (y = 0; y < s->avctx->height; y++) {
757 
758  /* re-init variables for the next line iteration */
759  horiz_pred = 0;
760  current_pixel_pair = (unsigned int *)current_line;
761  vert_pred = s->vert_pred;
762  mb_change_index = 0;
763  mb_change_byte = mb_change_bits[mb_change_index++];
764  mb_change_byte_mask = 0x01;
765  pixels_left = s->avctx->width;
766 
767  while (pixels_left > 0) {
768 
769  if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
770 
771  switch (y & 3) {
772  case 0:
773  /* if macroblock width is 2, apply C-Y-C-Y; else
774  * apply C-Y-Y */
775  if (s->block_width == 2) {
776  APPLY_C_PREDICTOR_24();
777  APPLY_Y_PREDICTOR_24();
778  OUTPUT_PIXEL_PAIR();
779  APPLY_C_PREDICTOR_24();
780  APPLY_Y_PREDICTOR_24();
781  OUTPUT_PIXEL_PAIR();
782  } else {
783  APPLY_C_PREDICTOR_24();
784  APPLY_Y_PREDICTOR_24();
785  OUTPUT_PIXEL_PAIR();
786  APPLY_Y_PREDICTOR_24();
787  OUTPUT_PIXEL_PAIR();
788  }
789  break;
790 
791  case 1:
792  case 3:
793  /* always apply 2 Y predictors on these iterations */
794  APPLY_Y_PREDICTOR_24();
795  OUTPUT_PIXEL_PAIR();
796  APPLY_Y_PREDICTOR_24();
797  OUTPUT_PIXEL_PAIR();
798  break;
799 
800  case 2:
801  /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
802  * depending on the macroblock type */
803  if (s->block_type == BLOCK_2x2) {
804  APPLY_C_PREDICTOR_24();
805  APPLY_Y_PREDICTOR_24();
806  OUTPUT_PIXEL_PAIR();
807  APPLY_C_PREDICTOR_24();
808  APPLY_Y_PREDICTOR_24();
809  OUTPUT_PIXEL_PAIR();
810  } else if (s->block_type == BLOCK_4x2) {
811  APPLY_C_PREDICTOR_24();
812  APPLY_Y_PREDICTOR_24();
813  OUTPUT_PIXEL_PAIR();
814  APPLY_Y_PREDICTOR_24();
815  OUTPUT_PIXEL_PAIR();
816  } else {
817  APPLY_Y_PREDICTOR_24();
818  OUTPUT_PIXEL_PAIR();
819  APPLY_Y_PREDICTOR_24();
820  OUTPUT_PIXEL_PAIR();
821  }
822  break;
823  }
824 
825  } else {
826 
827  /* skip (copy) four pixels, but reassign the horizontal
828  * predictor */
829  *vert_pred++ = *current_pixel_pair++;
830  horiz_pred = *current_pixel_pair - *vert_pred;
831  *vert_pred++ = *current_pixel_pair++;
832 
833  }
834 
835  if (!keyframe) {
836  mb_change_byte_mask <<= 1;
837 
838  /* next byte */
839  if (!mb_change_byte_mask) {
840  mb_change_byte = mb_change_bits[mb_change_index++];
841  mb_change_byte_mask = 0x01;
842  }
843  }
844 
845  pixels_left -= 2;
846  }
847 
848  /* next change row */
849  if (((y + 1) & 3) == 0)
850  mb_change_bits += s->mb_change_bits_row_size;
851 
852  current_line += s->frame->linesize[0];
853  }
854 }
855 
856 
857 static int truemotion1_decode_frame(AVCodecContext *avctx,
858  void *data, int *got_frame,
859  AVPacket *avpkt)
860 {
861  const uint8_t *buf = avpkt->data;
862  int ret, buf_size = avpkt->size;
863  TrueMotion1Context *s = avctx->priv_data;
864 
865  s->buf = buf;
866  s->size = buf_size;
867 
868  if ((ret = truemotion1_decode_header(s)) < 0)
869  return ret;
870 
871  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
872  return ret;
873 
874  if (compression_types[s->compression].algorithm == ALGO_RGB24H) {
875  truemotion1_decode_24bit(s);
876  } else if (compression_types[s->compression].algorithm != ALGO_NOP) {
877  truemotion1_decode_16bit(s);
878  }
879 
880  if ((ret = av_frame_ref(data, s->frame)) < 0)
881  return ret;
882 
883  *got_frame = 1;
884 
885  /* report that the buffer was completely consumed */
886  return buf_size;
887 }
888 
889 static av_cold int truemotion1_decode_end(AVCodecContext *avctx)
890 {
891  TrueMotion1Context *s = avctx->priv_data;
892 
893  av_frame_free(&s->frame);
894  av_freep(&s->vert_pred);
895 
896  return 0;
897 }
898 
899 AVCodec ff_truemotion1_decoder = {
900  .name = "truemotion1",
901  .long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 1.0"),
902  .type = AVMEDIA_TYPE_VIDEO,
903  .id = AV_CODEC_ID_TRUEMOTION1,
904  .priv_data_size = sizeof(TrueMotion1Context),
905  .init = truemotion1_decode_init,
906  .close = truemotion1_decode_end,
907  .decode = truemotion1_decode_frame,
908  .capabilities = CODEC_CAP_DR1,
909 };
Generated on Mon Dec 9 2013 19:21:04 for FFmpeg by   doxygen 1.8.2