FFmpeg
xan.c
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1 /*
2  * Wing Commander/Xan Video Decoder
3  * Copyright (C) 2003 The FFmpeg project
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  * Xan video decoder for Wing Commander III computer game
25  * by Mario Brito (mbrito@student.dei.uc.pt)
26  * and Mike Melanson (melanson@pcisys.net)
27  *
28  * The xan_wc3 decoder outputs PAL8 data.
29  */
30 
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #include "libavutil/intreadwrite.h"
36 #include "libavutil/mem.h"
37 
38 #define BITSTREAM_READER_LE
39 #include "avcodec.h"
40 #include "bytestream.h"
41 #include "get_bits.h"
42 #include "internal.h"
43 
44 #define RUNTIME_GAMMA 0
45 
46 #define VGA__TAG MKTAG('V', 'G', 'A', ' ')
47 #define PALT_TAG MKTAG('P', 'A', 'L', 'T')
48 #define SHOT_TAG MKTAG('S', 'H', 'O', 'T')
49 #define PALETTE_COUNT 256
50 #define PALETTE_SIZE (PALETTE_COUNT * 3)
51 #define PALETTES_MAX 256
52 
53 typedef struct XanContext {
54 
57 
58  const uint8_t *buf;
59  int size;
60 
61  /* scratch space */
66 
67  unsigned *palettes;
70 
72 
73 } XanContext;
74 
76 {
77  XanContext *s = avctx->priv_data;
78 
79  av_frame_free(&s->last_frame);
80 
81  av_freep(&s->buffer1);
82  av_freep(&s->buffer2);
83  av_freep(&s->palettes);
84 
85  return 0;
86 }
87 
89 {
90  XanContext *s = avctx->priv_data;
91 
92  s->avctx = avctx;
93  s->frame_size = 0;
94 
95  avctx->pix_fmt = AV_PIX_FMT_PAL8;
96 
97  s->buffer1_size = avctx->width * avctx->height;
98  s->buffer1 = av_malloc(s->buffer1_size);
99  if (!s->buffer1)
100  return AVERROR(ENOMEM);
101  s->buffer2_size = avctx->width * avctx->height;
102  s->buffer2 = av_malloc(s->buffer2_size + 130);
103  if (!s->buffer2) {
104  av_freep(&s->buffer1);
105  return AVERROR(ENOMEM);
106  }
107 
108  s->last_frame = av_frame_alloc();
109  if (!s->last_frame) {
110  xan_decode_end(avctx);
111  return AVERROR(ENOMEM);
112  }
113 
114  return 0;
115 }
116 
117 static int xan_huffman_decode(uint8_t *dest, int dest_len,
118  const uint8_t *src, int src_len)
119 {
120  uint8_t byte = *src++;
121  uint8_t ival = byte + 0x16;
122  const uint8_t * ptr = src + byte*2;
123  int ptr_len = src_len - 1 - byte*2;
124  uint8_t val = ival;
125  uint8_t *dest_end = dest + dest_len;
126  uint8_t *dest_start = dest;
127  int ret;
128  GetBitContext gb;
129 
130  if ((ret = init_get_bits8(&gb, ptr, ptr_len)) < 0)
131  return ret;
132 
133  while (val != 0x16) {
134  unsigned idx;
135  if (get_bits_left(&gb) < 1)
136  return AVERROR_INVALIDDATA;
137  idx = val - 0x17 + get_bits1(&gb) * byte;
138  if (idx >= 2 * byte)
139  return AVERROR_INVALIDDATA;
140  val = src[idx];
141 
142  if (val < 0x16) {
143  if (dest >= dest_end)
144  return dest_len;
145  *dest++ = val;
146  val = ival;
147  }
148  }
149 
150  return dest - dest_start;
151 }
152 
153 /**
154  * unpack simple compression
155  *
156  * @param dest destination buffer of dest_len, must be padded with at least 130 bytes
157  */
158 static void xan_unpack(uint8_t *dest, int dest_len,
159  const uint8_t *src, int src_len)
160 {
161  uint8_t opcode;
162  int size;
163  uint8_t *dest_org = dest;
164  uint8_t *dest_end = dest + dest_len;
166 
167  bytestream2_init(&ctx, src, src_len);
168  while (dest < dest_end && bytestream2_get_bytes_left(&ctx)) {
169  opcode = bytestream2_get_byte(&ctx);
170 
171  if (opcode < 0xe0) {
172  int size2, back;
173  if ((opcode & 0x80) == 0) {
174  size = opcode & 3;
175 
176  back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&ctx) + 1;
177  size2 = ((opcode & 0x1c) >> 2) + 3;
178  } else if ((opcode & 0x40) == 0) {
179  size = bytestream2_peek_byte(&ctx) >> 6;
180 
181  back = (bytestream2_get_be16(&ctx) & 0x3fff) + 1;
182  size2 = (opcode & 0x3f) + 4;
183  } else {
184  size = opcode & 3;
185 
186  back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&ctx) + 1;
187  size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&ctx) + 5;
188  }
189 
190  if (dest_end - dest < size + size2 ||
191  dest + size - dest_org < back ||
193  return;
195  dest += size;
196  av_memcpy_backptr(dest, back, size2);
197  dest += size2;
198  } else {
199  int finish = opcode >= 0xfc;
200  size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
201 
202  if (dest_end - dest < size || bytestream2_get_bytes_left(&ctx) < size)
203  return;
205  dest += size;
206  if (finish)
207  return;
208  }
209  }
210 }
211 
213  const uint8_t *pixel_buffer, int x, int y, int pixel_count)
214 {
215  int stride;
216  int line_inc;
217  int index;
218  int current_x;
219  int width = s->avctx->width;
220  uint8_t *palette_plane;
221 
222  palette_plane = frame->data[0];
223  stride = frame->linesize[0];
224  line_inc = stride - width;
225  index = y * stride + x;
226  current_x = x;
227  while (pixel_count && index < s->frame_size) {
228  int count = FFMIN(pixel_count, width - current_x);
229  memcpy(palette_plane + index, pixel_buffer, count);
230  pixel_count -= count;
231  index += count;
232  pixel_buffer += count;
233  current_x += count;
234 
235  if (current_x >= width) {
236  index += line_inc;
237  current_x = 0;
238  }
239  }
240 }
241 
243  int x, int y,
244  int pixel_count, int motion_x,
245  int motion_y)
246 {
247  int stride;
248  int line_inc;
249  int curframe_index, prevframe_index;
250  int curframe_x, prevframe_x;
251  int width = s->avctx->width;
252  uint8_t *palette_plane, *prev_palette_plane;
253 
254  if (y + motion_y < 0 || y + motion_y >= s->avctx->height ||
255  x + motion_x < 0 || x + motion_x >= s->avctx->width)
256  return;
257 
258  palette_plane = frame->data[0];
259  prev_palette_plane = s->last_frame->data[0];
260  if (!prev_palette_plane)
261  prev_palette_plane = palette_plane;
262  stride = frame->linesize[0];
263  line_inc = stride - width;
264  curframe_index = y * stride + x;
265  curframe_x = x;
266  prevframe_index = (y + motion_y) * stride + x + motion_x;
267  prevframe_x = x + motion_x;
268 
269  if (prev_palette_plane == palette_plane && FFABS(motion_x + width*motion_y) < pixel_count) {
270  avpriv_request_sample(s->avctx, "Overlapping copy");
271  return ;
272  }
273 
274  while (pixel_count &&
275  curframe_index < s->frame_size &&
276  prevframe_index < s->frame_size) {
277  int count = FFMIN3(pixel_count, width - curframe_x,
278  width - prevframe_x);
279 
280  memcpy(palette_plane + curframe_index,
281  prev_palette_plane + prevframe_index, count);
282  pixel_count -= count;
283  curframe_index += count;
284  prevframe_index += count;
285  curframe_x += count;
286  prevframe_x += count;
287 
288  if (curframe_x >= width) {
289  curframe_index += line_inc;
290  curframe_x = 0;
291  }
292 
293  if (prevframe_x >= width) {
294  prevframe_index += line_inc;
295  prevframe_x = 0;
296  }
297  }
298 }
299 
301 {
302 
303  int width = s->avctx->width;
304  int height = s->avctx->height;
305  int total_pixels = width * height;
306  uint8_t opcode;
307  uint8_t flag = 0;
308  int size = 0;
309  int motion_x, motion_y;
310  int x, y, ret;
311 
312  uint8_t *opcode_buffer = s->buffer1;
313  uint8_t *opcode_buffer_end = s->buffer1 + s->buffer1_size;
314  int opcode_buffer_size = s->buffer1_size;
315  const uint8_t *imagedata_buffer = s->buffer2;
316 
317  /* pointers to segments inside the compressed chunk */
318  const uint8_t *huffman_segment;
319  GetByteContext size_segment;
320  GetByteContext vector_segment;
321  const uint8_t *imagedata_segment;
322  int huffman_offset, size_offset, vector_offset, imagedata_offset,
323  imagedata_size;
324 
325  if (s->size < 8)
326  return AVERROR_INVALIDDATA;
327 
328  huffman_offset = AV_RL16(&s->buf[0]);
329  size_offset = AV_RL16(&s->buf[2]);
330  vector_offset = AV_RL16(&s->buf[4]);
331  imagedata_offset = AV_RL16(&s->buf[6]);
332 
333  if (huffman_offset >= s->size ||
334  size_offset >= s->size ||
335  vector_offset >= s->size ||
336  imagedata_offset >= s->size)
337  return AVERROR_INVALIDDATA;
338 
339  huffman_segment = s->buf + huffman_offset;
340  bytestream2_init(&size_segment, s->buf + size_offset, s->size - size_offset);
341  bytestream2_init(&vector_segment, s->buf + vector_offset, s->size - vector_offset);
342  imagedata_segment = s->buf + imagedata_offset;
343 
344  if ((ret = xan_huffman_decode(opcode_buffer, opcode_buffer_size,
345  huffman_segment, s->size - huffman_offset)) < 0)
346  return AVERROR_INVALIDDATA;
347  opcode_buffer_end = opcode_buffer + ret;
348 
349  if (imagedata_segment[0] == 2) {
350  xan_unpack(s->buffer2, s->buffer2_size,
351  &imagedata_segment[1], s->size - imagedata_offset - 1);
352  imagedata_size = s->buffer2_size;
353  } else {
354  imagedata_size = s->size - imagedata_offset - 1;
355  imagedata_buffer = &imagedata_segment[1];
356  }
357 
358  /* use the decoded data segments to build the frame */
359  x = y = 0;
360  while (total_pixels && opcode_buffer < opcode_buffer_end) {
361 
362  opcode = *opcode_buffer++;
363  size = 0;
364 
365  switch (opcode) {
366 
367  case 0:
368  flag ^= 1;
369  continue;
370 
371  case 1:
372  case 2:
373  case 3:
374  case 4:
375  case 5:
376  case 6:
377  case 7:
378  case 8:
379  size = opcode;
380  break;
381 
382  case 12:
383  case 13:
384  case 14:
385  case 15:
386  case 16:
387  case 17:
388  case 18:
389  size += (opcode - 10);
390  break;
391 
392  case 9:
393  case 19:
394  if (bytestream2_get_bytes_left(&size_segment) < 1) {
395  av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
396  return AVERROR_INVALIDDATA;
397  }
398  size = bytestream2_get_byte(&size_segment);
399  break;
400 
401  case 10:
402  case 20:
403  if (bytestream2_get_bytes_left(&size_segment) < 2) {
404  av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
405  return AVERROR_INVALIDDATA;
406  }
407  size = bytestream2_get_be16(&size_segment);
408  break;
409 
410  case 11:
411  case 21:
412  if (bytestream2_get_bytes_left(&size_segment) < 3) {
413  av_log(s->avctx, AV_LOG_ERROR, "size_segment overread\n");
414  return AVERROR_INVALIDDATA;
415  }
416  size = bytestream2_get_be24(&size_segment);
417  break;
418  }
419 
420  if (size > total_pixels)
421  break;
422 
423  if (opcode < 12) {
424  flag ^= 1;
425  if (flag) {
426  /* run of (size) pixels is unchanged from last frame */
427  xan_wc3_copy_pixel_run(s, frame, x, y, size, 0, 0);
428  } else {
429  /* output a run of pixels from imagedata_buffer */
430  if (imagedata_size < size)
431  break;
432  xan_wc3_output_pixel_run(s, frame, imagedata_buffer, x, y, size);
433  imagedata_buffer += size;
434  imagedata_size -= size;
435  }
436  } else {
437  uint8_t vector;
438  if (bytestream2_get_bytes_left(&vector_segment) <= 0) {
439  av_log(s->avctx, AV_LOG_ERROR, "vector_segment overread\n");
440  return AVERROR_INVALIDDATA;
441  }
442  /* run-based motion compensation from last frame */
443  vector = bytestream2_get_byte(&vector_segment);
444  motion_x = sign_extend(vector >> 4, 4);
445  motion_y = sign_extend(vector & 0xF, 4);
446 
447  /* copy a run of pixels from the previous frame */
448  xan_wc3_copy_pixel_run(s, frame, x, y, size, motion_x, motion_y);
449 
450  flag = 0;
451  }
452 
453  /* coordinate accounting */
454  total_pixels -= size;
455  y += (x + size) / width;
456  x = (x + size) % width;
457  }
458  return 0;
459 }
460 
461 #if RUNTIME_GAMMA
462 static inline unsigned mul(unsigned a, unsigned b)
463 {
464  return (a * b) >> 16;
465 }
466 
467 static inline unsigned pow4(unsigned a)
468 {
469  unsigned square = mul(a, a);
470  return mul(square, square);
471 }
472 
473 static inline unsigned pow5(unsigned a)
474 {
475  return mul(pow4(a), a);
476 }
477 
478 static uint8_t gamma_corr(uint8_t in) {
479  unsigned lo, hi = 0xff40, target;
480  int i = 15;
481  in = (in << 2) | (in >> 6);
482  /* equivalent float code:
483  if (in >= 252)
484  return 253;
485  return round(pow(in / 256.0, 0.8) * 256);
486  */
487  lo = target = in << 8;
488  do {
489  unsigned mid = (lo + hi) >> 1;
490  unsigned pow = pow5(mid);
491  if (pow > target) hi = mid;
492  else lo = mid;
493  } while (--i);
494  return (pow4((lo + hi) >> 1) + 0x80) >> 8;
495 }
496 #else
497 /**
498  * This is a gamma correction that xan3 applies to all palette entries.
499  *
500  * There is a peculiarity, namely that the values are clamped to 253 -
501  * it seems likely that this table was calculated by a buggy fixed-point
502  * implementation, the one above under RUNTIME_GAMMA behaves like this for
503  * example.
504  * The exponent value of 0.8 can be explained by this as well, since 0.8 = 4/5
505  * and thus pow(x, 0.8) is still easy to calculate.
506  * Also, the input values are first rotated to the left by 2.
507  */
508 static const uint8_t gamma_lookup[256] = {
509  0x00, 0x09, 0x10, 0x16, 0x1C, 0x21, 0x27, 0x2C,
510  0x31, 0x35, 0x3A, 0x3F, 0x43, 0x48, 0x4C, 0x50,
511  0x54, 0x59, 0x5D, 0x61, 0x65, 0x69, 0x6D, 0x71,
512  0x75, 0x79, 0x7D, 0x80, 0x84, 0x88, 0x8C, 0x8F,
513  0x93, 0x97, 0x9A, 0x9E, 0xA2, 0xA5, 0xA9, 0xAC,
514  0xB0, 0xB3, 0xB7, 0xBA, 0xBE, 0xC1, 0xC5, 0xC8,
515  0xCB, 0xCF, 0xD2, 0xD5, 0xD9, 0xDC, 0xDF, 0xE3,
516  0xE6, 0xE9, 0xED, 0xF0, 0xF3, 0xF6, 0xFA, 0xFD,
517  0x03, 0x0B, 0x12, 0x18, 0x1D, 0x23, 0x28, 0x2D,
518  0x32, 0x36, 0x3B, 0x40, 0x44, 0x49, 0x4D, 0x51,
519  0x56, 0x5A, 0x5E, 0x62, 0x66, 0x6A, 0x6E, 0x72,
520  0x76, 0x7A, 0x7D, 0x81, 0x85, 0x89, 0x8D, 0x90,
521  0x94, 0x98, 0x9B, 0x9F, 0xA2, 0xA6, 0xAA, 0xAD,
522  0xB1, 0xB4, 0xB8, 0xBB, 0xBF, 0xC2, 0xC5, 0xC9,
523  0xCC, 0xD0, 0xD3, 0xD6, 0xDA, 0xDD, 0xE0, 0xE4,
524  0xE7, 0xEA, 0xED, 0xF1, 0xF4, 0xF7, 0xFA, 0xFD,
525  0x05, 0x0D, 0x13, 0x19, 0x1F, 0x24, 0x29, 0x2E,
526  0x33, 0x38, 0x3C, 0x41, 0x45, 0x4A, 0x4E, 0x52,
527  0x57, 0x5B, 0x5F, 0x63, 0x67, 0x6B, 0x6F, 0x73,
528  0x77, 0x7B, 0x7E, 0x82, 0x86, 0x8A, 0x8D, 0x91,
529  0x95, 0x99, 0x9C, 0xA0, 0xA3, 0xA7, 0xAA, 0xAE,
530  0xB2, 0xB5, 0xB9, 0xBC, 0xBF, 0xC3, 0xC6, 0xCA,
531  0xCD, 0xD0, 0xD4, 0xD7, 0xDA, 0xDE, 0xE1, 0xE4,
532  0xE8, 0xEB, 0xEE, 0xF1, 0xF5, 0xF8, 0xFB, 0xFD,
533  0x07, 0x0E, 0x15, 0x1A, 0x20, 0x25, 0x2A, 0x2F,
534  0x34, 0x39, 0x3D, 0x42, 0x46, 0x4B, 0x4F, 0x53,
535  0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C, 0x70, 0x74,
536  0x78, 0x7C, 0x7F, 0x83, 0x87, 0x8B, 0x8E, 0x92,
537  0x96, 0x99, 0x9D, 0xA1, 0xA4, 0xA8, 0xAB, 0xAF,
538  0xB2, 0xB6, 0xB9, 0xBD, 0xC0, 0xC4, 0xC7, 0xCB,
539  0xCE, 0xD1, 0xD5, 0xD8, 0xDB, 0xDF, 0xE2, 0xE5,
540  0xE9, 0xEC, 0xEF, 0xF2, 0xF6, 0xF9, 0xFC, 0xFD
541 };
542 #endif
543 
545  void *data, int *got_frame,
546  AVPacket *avpkt)
547 {
548  AVFrame *frame = data;
549  const uint8_t *buf = avpkt->data;
550  int ret, buf_size = avpkt->size;
551  XanContext *s = avctx->priv_data;
553  int tag = 0;
554 
555  bytestream2_init(&ctx, buf, buf_size);
556  while (bytestream2_get_bytes_left(&ctx) > 8 && tag != VGA__TAG) {
557  unsigned *tmpptr;
558  uint32_t new_pal;
559  int size;
560  int i;
561  tag = bytestream2_get_le32(&ctx);
562  size = bytestream2_get_be32(&ctx);
563  if (size < 0) {
564  av_log(avctx, AV_LOG_ERROR, "Invalid tag size %d\n", size);
565  return AVERROR_INVALIDDATA;
566  }
568  switch (tag) {
569  case PALT_TAG:
570  if (size < PALETTE_SIZE)
571  return AVERROR_INVALIDDATA;
572  if (s->palettes_count >= PALETTES_MAX)
573  return AVERROR_INVALIDDATA;
574  tmpptr = av_realloc_array(s->palettes,
575  s->palettes_count + 1, AVPALETTE_SIZE);
576  if (!tmpptr)
577  return AVERROR(ENOMEM);
578  s->palettes = tmpptr;
579  tmpptr += s->palettes_count * AVPALETTE_COUNT;
580  for (i = 0; i < PALETTE_COUNT; i++) {
581 #if RUNTIME_GAMMA
582  int r = gamma_corr(bytestream2_get_byteu(&ctx));
583  int g = gamma_corr(bytestream2_get_byteu(&ctx));
584  int b = gamma_corr(bytestream2_get_byteu(&ctx));
585 #else
586  int r = gamma_lookup[bytestream2_get_byteu(&ctx)];
587  int g = gamma_lookup[bytestream2_get_byteu(&ctx)];
588  int b = gamma_lookup[bytestream2_get_byteu(&ctx)];
589 #endif
590  *tmpptr++ = (0xFFU << 24) | (r << 16) | (g << 8) | b;
591  }
592  s->palettes_count++;
593  break;
594  case SHOT_TAG:
595  if (size < 4)
596  return AVERROR_INVALIDDATA;
597  new_pal = bytestream2_get_le32(&ctx);
598  if (new_pal < s->palettes_count) {
599  s->cur_palette = new_pal;
600  } else
601  av_log(avctx, AV_LOG_ERROR, "Invalid palette selected\n");
602  break;
603  case VGA__TAG:
604  break;
605  default:
607  break;
608  }
609  }
610  buf_size = bytestream2_get_bytes_left(&ctx);
611 
612  if (s->palettes_count <= 0) {
613  av_log(s->avctx, AV_LOG_ERROR, "No palette found\n");
614  return AVERROR_INVALIDDATA;
615  }
616 
617  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
618  return ret;
619 
620  if (!s->frame_size)
621  s->frame_size = frame->linesize[0] * s->avctx->height;
622 
623  memcpy(frame->data[1],
624  s->palettes + s->cur_palette * AVPALETTE_COUNT, AVPALETTE_SIZE);
625 
626  s->buf = ctx.buffer;
627  s->size = buf_size;
628 
629  if (xan_wc3_decode_frame(s, frame) < 0)
630  return AVERROR_INVALIDDATA;
631 
632  av_frame_unref(s->last_frame);
633  if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
634  return ret;
635 
636  *got_frame = 1;
637 
638  /* always report that the buffer was completely consumed */
639  return buf_size;
640 }
641 
643  .name = "xan_wc3",
644  .long_name = NULL_IF_CONFIG_SMALL("Wing Commander III / Xan"),
645  .type = AVMEDIA_TYPE_VIDEO,
646  .id = AV_CODEC_ID_XAN_WC3,
647  .priv_data_size = sizeof(XanContext),
649  .close = xan_decode_end,
651  .capabilities = AV_CODEC_CAP_DR1,
652 };
gamma_lookup
static const uint8_t gamma_lookup[256]
This is a gamma correction that xan3 applies to all palette entries.
Definition: xan.c:508
AVCodec
AVCodec.
Definition: codec.h:190
stride
int stride
Definition: mace.c:144
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
r
const char * r
Definition: vf_curves.c:114
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
ff_xan_wc3_decoder
AVCodec ff_xan_wc3_decoder
Definition: xan.c:642
GetByteContext
Definition: bytestream.h:33
XanContext::last_frame
AVFrame * last_frame
Definition: xan.c:56
xan_wc3_copy_pixel_run
static void xan_wc3_copy_pixel_run(XanContext *s, AVFrame *frame, int x, int y, int pixel_count, int motion_x, int motion_y)
Definition: xan.c:242
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:300
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:355
b
#define b
Definition: input.c:41
data
const char data[16]
Definition: mxf.c:91
XanContext::buffer1
uint8_t * buffer1
Definition: xan.c:62
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
xan_unpack
static void xan_unpack(uint8_t *dest, int dest_len, const uint8_t *src, int src_len)
unpack simple compression
Definition: xan.c:158
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:164
return
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a it should return
Definition: filter_design.txt:264
finish
static void finish(void)
Definition: movenc.c:345
U
#define U(x)
Definition: vp56_arith.h:37
GetBitContext
Definition: get_bits.h:61
SHOT_TAG
#define SHOT_TAG
Definition: xan.c:48
val
static double val(void *priv, double ch)
Definition: aeval.c:76
FFMIN3
#define FFMIN3(a, b, c)
Definition: common.h:97
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
xan_decode_end
static av_cold int xan_decode_end(AVCodecContext *avctx)
Definition: xan.c:75
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
av_cold
#define av_cold
Definition: attributes.h:90
XanContext::buf
const uint8_t * buf
Definition: xan.c:58
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
av_memcpy_backptr
void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
Overlapping memcpy() implementation.
Definition: mem.c:428
XanContext::palettes
unsigned * palettes
Definition: xan.c:67
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
width
#define width
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_realloc_array
void * av_realloc_array(void *ptr, size_t nmemb, size_t size)
Definition: mem.c:198
g
const char * g
Definition: vf_curves.c:115
AV_GET_BUFFER_FLAG_REF
#define AV_GET_BUFFER_FLAG_REF
The decoder will keep a reference to the frame and may reuse it later.
Definition: avcodec.h:509
frame_size
int frame_size
Definition: mxfenc.c:2137
XanContext::frame_size
int frame_size
Definition: xan.c:71
ctx
AVFormatContext * ctx
Definition: movenc.c:48
get_bits.h
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:90
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
PALETTE_COUNT
#define PALETTE_COUNT
Definition: xan.c:49
get_bits1
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
src
#define src
Definition: vp8dsp.c:254
XanContext::buffer2_size
int buffer2_size
Definition: xan.c:65
bytestream2_get_buffer
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
PALT_TAG
#define PALT_TAG
Definition: xan.c:47
VGA__TAG
#define VGA__TAG
Definition: xan.c:46
index
int index
Definition: gxfenc.c:89
AVPALETTE_COUNT
#define AVPALETTE_COUNT
Definition: pixfmt.h:33
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1854
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:50
AVPacket::size
int size
Definition: packet.h:356
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:188
byte
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_WB16 unsigned int_TMPL byte
Definition: bytestream.h:95
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:444
xan_decode_frame
static int xan_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: xan.c:544
size
int size
Definition: twinvq_data.h:11134
XanContext::avctx
AVCodecContext * avctx
Definition: xan.c:55
PALETTE_SIZE
#define PALETTE_SIZE
Definition: xan.c:50
xan_huffman_decode
static int xan_huffman_decode(uint8_t *dest, int dest_len, const uint8_t *src, int src_len)
Definition: xan.c:117
xan_decode_init
static av_cold int xan_decode_init(AVCodecContext *avctx)
Definition: xan.c:88
height
#define height
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
FFMIN
#define FFMIN(a, b)
Definition: common.h:96
AV_CODEC_ID_XAN_WC3
@ AV_CODEC_ID_XAN_WC3
Definition: codec_id.h:89
flag
#define flag(name)
Definition: cbs_av1.c:557
in
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi - 0x80) *(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t, *(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t, *(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31)))) #define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac) { } void ff_audio_convert_free(AudioConvert **ac) { if(! *ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);} AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map) { AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method !=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt) > 2) { ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc) { av_free(ac);return NULL;} return ac;} in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar) { ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar ? ac->channels :1;} else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);return ac;} int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in) { int use_generic=1;int len=in->nb_samples;int p;if(ac->dc) { av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
Definition: audio_convert.c:326
XanContext::size
int size
Definition: xan.c:59
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
XanContext
Definition: xan.c:53
uint8_t
uint8_t
Definition: audio_convert.c:194
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:554
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:197
AVCodecContext::height
int height
Definition: avcodec.h:699
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:736
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
tag
uint32_t tag
Definition: movenc.c:1532
ret
ret
Definition: filter_design.txt:187
xan_wc3_decode_frame
static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame)
Definition: xan.c:300
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
square
static int square(int x)
Definition: roqvideoenc.c:113
XanContext::buffer1_size
int buffer1_size
Definition: xan.c:63
AVCodecContext
main external API structure.
Definition: avcodec.h:526
xan_wc3_output_pixel_run
static void xan_wc3_output_pixel_run(XanContext *s, AVFrame *frame, const uint8_t *pixel_buffer, int x, int y, int pixel_count)
Definition: xan.c:212
sign_extend
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:130
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
mem.h
XanContext::cur_palette
int cur_palette
Definition: xan.c:69
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:39
AVPacket
This structure stores compressed data.
Definition: packet.h:332
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:553
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
XanContext::palettes_count
int palettes_count
Definition: xan.c:68
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:699
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
XanContext::buffer2
uint8_t * buffer2
Definition: xan.c:64
PALETTES_MAX
#define PALETTES_MAX
Definition: xan.c:51