FFmpeg
cdtoons.c
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1 /*
2  * CDToons video decoder
3  * Copyright (C) 2020 Alyssa Milburn <amilburn@zall.org>
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  * CDToons video decoder
25  * @author Alyssa Milburn <amilburn@zall.org>
26  */
27 
28 #include <stdint.h>
29 
30 #include "libavutil/attributes.h"
31 #include "libavutil/internal.h"
32 #include "avcodec.h"
33 #include "bytestream.h"
34 #include "internal.h"
35 
36 #define CDTOONS_HEADER_SIZE 44
37 #define CDTOONS_MAX_SPRITES 1200
38 
39 typedef struct CDToonsSprite {
40  uint16_t flags;
41  uint16_t owner_frame;
42  uint16_t start_frame;
43  uint16_t end_frame;
44  unsigned int alloc_size;
45  uint32_t size;
47  int active;
49 
50 typedef struct CDToonsContext {
52 
53  uint16_t last_pal_id; ///< The index of the active palette sprite.
54  uint32_t pal[256]; ///< The currently-used palette data.
57 
59  uint32_t data_size,
60  int dst_x, int dst_y, int width, int height)
61 {
62  CDToonsContext *c = avctx->priv_data;
63  const uint8_t *next_line = data;
64  const uint8_t *end = data + data_size;
65  uint16_t line_size;
66  uint8_t *dest;
67  int skip = 0, to_skip, x;
68 
69  if (dst_x + width > avctx->width)
70  width = avctx->width - dst_x;
71  if (dst_y + height > avctx->height)
72  height = avctx->height - dst_y;
73 
74  if (dst_x < 0) {
75  /* we need to skip the start of the scanlines */
76  skip = -dst_x;
77  if (width <= skip)
78  return 0;
79  dst_x = 0;
80  }
81 
82  for (int y = 0; y < height; y++) {
83  /* one scanline at a time, size is provided */
84  data = next_line;
85  if (end - data < 2)
86  return 1;
87  line_size = bytestream_get_be16(&data);
88  if (end - data < line_size)
89  return 1;
90  next_line = data + line_size;
91  if (dst_y + y < 0)
92  continue;
93 
94  dest = c->frame->data[0] + (dst_y + y) * c->frame->linesize[0] + dst_x;
95 
96  to_skip = skip;
97  x = 0;
98  while (x < width - skip) {
99  int raw, size, step;
100  uint8_t val;
101 
102  if (data >= end)
103  return 1;
104 
105  val = bytestream_get_byte(&data);
106  raw = !(val & 0x80);
107  size = (int)(val & 0x7F) + 1;
108 
109  /* skip the start of a scanline if it is off-screen */
110  if (to_skip >= size) {
111  to_skip -= size;
112  if (raw) {
113  step = size;
114  } else {
115  step = 1;
116  }
117  if (next_line - data < step)
118  return 1;
119  data += step;
120  continue;
121  } else if (to_skip) {
122  size -= to_skip;
123  if (raw) {
124  if (next_line - data < to_skip)
125  return 1;
126  data += to_skip;
127  }
128  to_skip = 0;
129  }
130 
131  if (x + size >= width - skip)
132  size = width - skip - x;
133 
134  /* either raw data, or a run of a single color */
135  if (raw) {
136  if (next_line - data < size)
137  return 1;
138  memcpy(dest + x, data, size);
139  data += size;
140  } else {
141  uint8_t color = bytestream_get_byte(&data);
142  /* ignore transparent runs */
143  if (color)
144  memset(dest + x, color, size);
145  }
146  x += size;
147  }
148  }
149 
150  return 0;
151 }
152 
153 static int cdtoons_decode_frame(AVCodecContext *avctx, void *data,
154  int *got_frame, AVPacket *avpkt)
155 {
156  CDToonsContext *c = avctx->priv_data;
157  const uint8_t *buf = avpkt->data;
158  const uint8_t *eod = avpkt->data + avpkt->size;
159  const int buf_size = avpkt->size;
160  uint16_t frame_id;
161  uint8_t background_color;
162  uint16_t sprite_count, sprite_offset;
163  uint8_t referenced_count;
164  uint16_t palette_id;
165  uint8_t palette_set;
166  int ret;
167  int saw_embedded_sprites = 0;
168 
169  if (buf_size < CDTOONS_HEADER_SIZE)
170  return AVERROR_INVALIDDATA;
171 
172  if ((ret = ff_reget_buffer(avctx, c->frame, 0)) < 0)
173  return ret;
174 
175  /* a lot of the header is useless junk in the absence of
176  * dirty rectangling etc */
177  buf += 2; /* version? (always 9?) */
178  frame_id = bytestream_get_be16(&buf);
179  buf += 2; /* blocks_valid_until */
180  buf += 1;
181  background_color = bytestream_get_byte(&buf);
182  buf += 16; /* clip rect, dirty rect */
183  buf += 4; /* flags */
184  sprite_count = bytestream_get_be16(&buf);
185  sprite_offset = bytestream_get_be16(&buf);
186  buf += 2; /* max block id? */
187  referenced_count = bytestream_get_byte(&buf);
188  buf += 1;
189  palette_id = bytestream_get_be16(&buf);
190  palette_set = bytestream_get_byte(&buf);
191  buf += 5;
192 
193  if (sprite_offset > buf_size)
194  return AVERROR_INVALIDDATA;
195 
196  /* read new sprites introduced in this frame */
197  buf = avpkt->data + sprite_offset;
198  while (sprite_count--) {
199  uint32_t size;
200  uint16_t sprite_id;
201 
202  if (buf + 14 > eod)
203  return AVERROR_INVALIDDATA;
204 
205  sprite_id = bytestream_get_be16(&buf);
206  if (sprite_id >= CDTOONS_MAX_SPRITES) {
207  av_log(avctx, AV_LOG_ERROR,
208  "Sprite ID %d is too high.\n", sprite_id);
209  return AVERROR_INVALIDDATA;
210  }
211  if (c->sprites[sprite_id].active) {
212  av_log(avctx, AV_LOG_ERROR,
213  "Sprite ID %d is a duplicate.\n", sprite_id);
214  return AVERROR_INVALIDDATA;
215  }
216 
217  c->sprites[sprite_id].flags = bytestream_get_be16(&buf);
218  size = bytestream_get_be32(&buf);
219  if (size < 14) {
220  av_log(avctx, AV_LOG_ERROR,
221  "Sprite only has %d bytes of data.\n", size);
222  return AVERROR_INVALIDDATA;
223  }
224  size -= 14;
225  c->sprites[sprite_id].size = size;
226  c->sprites[sprite_id].owner_frame = frame_id;
227  c->sprites[sprite_id].start_frame = bytestream_get_be16(&buf);
228  c->sprites[sprite_id].end_frame = bytestream_get_be16(&buf);
229  buf += 2;
230 
231  if (size > buf_size || buf + size > eod)
232  return AVERROR_INVALIDDATA;
233 
234  av_fast_padded_malloc(&c->sprites[sprite_id].data, &c->sprites[sprite_id].alloc_size, size);
235  if (!c->sprites[sprite_id].data)
236  return AVERROR(ENOMEM);
237 
238  c->sprites[sprite_id].active = 1;
239 
240  bytestream_get_buffer(&buf, c->sprites[sprite_id].data, size);
241  }
242 
243  /* render any embedded sprites */
244  while (buf < eod) {
245  uint32_t tag, size;
246  if (buf + 8 > eod) {
247  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for embedded sprites.\n");
248  return AVERROR_INVALIDDATA;
249  }
250  tag = bytestream_get_be32(&buf);
251  size = bytestream_get_be32(&buf);
252  if (tag == MKBETAG('D', 'i', 'f', 'f')) {
253  uint16_t diff_count;
254  if (buf + 10 > eod) {
255  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame.\n");
256  return AVERROR_INVALIDDATA;
257  }
258  diff_count = bytestream_get_be16(&buf);
259  buf += 8; /* clip rect? */
260  for (int i = 0; i < diff_count; i++) {
261  int16_t top, left;
262  uint16_t diff_size, width, height;
263 
264  if (buf + 16 > eod) {
265  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame header.\n");
266  return AVERROR_INVALIDDATA;
267  }
268 
269  top = bytestream_get_be16(&buf);
270  left = bytestream_get_be16(&buf);
271  buf += 4; /* bottom, right */
272  diff_size = bytestream_get_be32(&buf);
273  width = bytestream_get_be16(&buf);
274  height = bytestream_get_be16(&buf);
275  if (diff_size < 8 || diff_size - 4 > eod - buf) {
276  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame data.\n");
277  return AVERROR_INVALIDDATA;
278  }
279  if (cdtoons_render_sprite(avctx, buf + 4, diff_size - 8,
280  left, top, width, height)) {
281  av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
282  }
283  buf += diff_size - 4;
284  }
285  saw_embedded_sprites = 1;
286  } else {
287  /* we don't care about any other entries */
288  if (size < 8 || size - 8 > eod - buf) {
289  av_log(avctx, AV_LOG_WARNING, "Ran out of data for ignored entry (size %X, %d left).\n", size, (int)(eod - buf));
290  return AVERROR_INVALIDDATA;
291  }
292  buf += (size - 8);
293  }
294  }
295 
296  /* was an intra frame? */
297  if (saw_embedded_sprites)
298  goto done;
299 
300  /* render any referenced sprites */
301  buf = avpkt->data + CDTOONS_HEADER_SIZE;
302  eod = avpkt->data + sprite_offset;
303  for (int i = 0; i < referenced_count; i++) {
304  const uint8_t *block_data;
305  uint16_t sprite_id, width, height;
306  int16_t top, left, right;
307 
308  if (buf + 10 > eod) {
309  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data when rendering.\n");
310  return AVERROR_INVALIDDATA;
311  }
312 
313  sprite_id = bytestream_get_be16(&buf);
314  top = bytestream_get_be16(&buf);
315  left = bytestream_get_be16(&buf);
316  buf += 2; /* bottom */
317  right = bytestream_get_be16(&buf);
318 
319  if ((i == 0) && (sprite_id == 0)) {
320  /* clear background */
321  memset(c->frame->data[0], background_color,
322  c->frame->linesize[0] * avctx->height);
323  }
324 
325  if (!right)
326  continue;
327  if (sprite_id >= CDTOONS_MAX_SPRITES) {
328  av_log(avctx, AV_LOG_ERROR,
329  "Sprite ID %d is too high.\n", sprite_id);
330  return AVERROR_INVALIDDATA;
331  }
332 
333  block_data = c->sprites[sprite_id].data;
334  if (!c->sprites[sprite_id].active) {
335  /* this can happen when seeking around */
336  av_log(avctx, AV_LOG_WARNING, "Sprite %d is missing.\n", sprite_id);
337  continue;
338  }
339  if (c->sprites[sprite_id].size < 14) {
340  av_log(avctx, AV_LOG_ERROR, "Sprite %d is too small.\n", sprite_id);
341  continue;
342  }
343 
344  height = bytestream_get_be16(&block_data);
345  width = bytestream_get_be16(&block_data);
346  block_data += 10;
347  if (cdtoons_render_sprite(avctx, block_data,
348  c->sprites[sprite_id].size - 14,
349  left, top, width, height)) {
350  av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
351  }
352  }
353 
354  if (palette_id && (palette_id != c->last_pal_id)) {
355  if (palette_id >= CDTOONS_MAX_SPRITES) {
356  av_log(avctx, AV_LOG_ERROR,
357  "Palette ID %d is too high.\n", palette_id);
358  return AVERROR_INVALIDDATA;
359  }
360  if (!c->sprites[palette_id].active) {
361  /* this can happen when seeking around */
362  av_log(avctx, AV_LOG_WARNING,
363  "Palette ID %d is missing.\n", palette_id);
364  goto done;
365  }
366  if (c->sprites[palette_id].size != 256 * 2 * 3) {
367  av_log(avctx, AV_LOG_ERROR,
368  "Palette ID %d is wrong size (%d).\n",
369  palette_id, c->sprites[palette_id].size);
370  return AVERROR_INVALIDDATA;
371  }
372  c->last_pal_id = palette_id;
373  if (!palette_set) {
374  uint8_t *palette_data = c->sprites[palette_id].data;
375  for (int i = 0; i < 256; i++) {
376  /* QuickTime-ish palette: 16-bit RGB components */
377  unsigned r, g, b;
378  r = *palette_data;
379  g = *(palette_data + 2);
380  b = *(palette_data + 4);
381  c->pal[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
382  palette_data += 6;
383  }
384  /* first palette entry indicates transparency */
385  c->pal[0] = 0;
386  c->frame->palette_has_changed = 1;
387  }
388  }
389 
390 done:
391  /* discard outdated blocks */
392  for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
393  if (c->sprites[i].end_frame > frame_id)
394  continue;
395  c->sprites[i].active = 0;
396  }
397 
398  memcpy(c->frame->data[1], c->pal, AVPALETTE_SIZE);
399 
400  if ((ret = av_frame_ref(data, c->frame)) < 0)
401  return ret;
402 
403  *got_frame = 1;
404 
405  /* always report that the buffer was completely consumed */
406  return buf_size;
407 }
408 
410 {
411  CDToonsContext *c = avctx->priv_data;
412 
413  avctx->pix_fmt = AV_PIX_FMT_PAL8;
414  c->last_pal_id = 0;
415  c->frame = av_frame_alloc();
416  if (!c->frame)
417  return AVERROR(ENOMEM);
418 
419  return 0;
420 }
421 
422 static void cdtoons_flush(AVCodecContext *avctx)
423 {
424  CDToonsContext *c = avctx->priv_data;
425 
426  c->last_pal_id = 0;
427  for (int i = 0; i < CDTOONS_MAX_SPRITES; i++)
428  c->sprites[i].active = 0;
429 }
430 
432 {
433  CDToonsContext *c = avctx->priv_data;
434 
435  for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
436  av_freep(&c->sprites[i].data);
437  c->sprites[i].active = 0;
438  }
439 
440  av_frame_free(&c->frame);
441 
442  return 0;
443 }
444 
446  .name = "cdtoons",
447  .long_name = NULL_IF_CONFIG_SMALL("CDToons video"),
448  .type = AVMEDIA_TYPE_VIDEO,
449  .id = AV_CODEC_ID_CDTOONS,
450  .priv_data_size = sizeof(CDToonsContext),
452  .close = cdtoons_decode_end,
454  .capabilities = AV_CODEC_CAP_DR1,
455  .flush = cdtoons_flush,
456 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:314
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static void flush(AVCodecContext *avctx)
unsigned int alloc_size
Definition: cdtoons.c:44
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:200
const char * g
Definition: vf_curves.c:115
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: packet.h:364
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:741
void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size)
Same behaviour av_fast_malloc but the buffer has additional AV_INPUT_BUFFER_PADDING_SIZE at the end w...
Definition: utils.c:72
static av_cold int cdtoons_decode_end(AVCodecContext *avctx)
Definition: cdtoons.c:431
AVCodec.
Definition: codec.h:190
uint16_t flags
Definition: cdtoons.c:40
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
Macro definitions for various function/variable attributes.
CDToonsSprite sprites[CDTOONS_MAX_SPRITES]
Definition: cdtoons.c:55
uint8_t
#define av_cold
Definition: attributes.h:88
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
#define CDTOONS_HEADER_SIZE
Definition: cdtoons.c:36
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:92
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
uint16_t owner_frame
Definition: cdtoons.c:41
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:443
#define height
uint8_t * data
Definition: packet.h:363
uint32_t tag
Definition: movenc.c:1597
ptrdiff_t size
Definition: opengl_enc.c:100
#define av_log(a,...)
#define U(x)
Definition: vp56_arith.h:37
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available...
Definition: decode.c:1986
const char * r
Definition: vf_curves.c:114
const char * name
Name of the codec implementation.
Definition: codec.h:197
AVCodec ff_cdtoons_decoder
Definition: cdtoons.c:445
#define CDTOONS_MAX_SPRITES
Definition: cdtoons.c:37
common internal API header
#define b
Definition: input.c:41
#define width
int width
picture width / height.
Definition: avcodec.h:704
static void cdtoons_flush(AVCodecContext *avctx)
Definition: cdtoons.c:422
static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b, uint8_t *dst, unsigned int size)
Definition: bytestream.h:363
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:345
main external API structure.
Definition: avcodec.h:531
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2]...the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so...,+,-,+,-,+,+,-,+,-,+,...hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32-hcoeff[1]-hcoeff[2]-...a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2}an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||.........intra?||||:Block01:yes no||||:Block02:.................||||:Block03::y DC::ref index:||||:Block04::cb DC::motion x:||||.........:cr DC::motion y:||||.................|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------------------------------|||Y subbands||Cb subbands||Cr subbands||||------||------||------|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||------||------||------||||------||------||------|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||------||------||------||||------||------||------|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||------||------||------||||------||------||------|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------------------------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction------------|\Dequantization-------------------\||Reference frames|\IDWT|--------------|Motion\|||Frame 0||Frame 1||Compensation.OBMC v-------|--------------|--------------.\------> Frame n output Frame Frame<----------------------------------/|...|-------------------Range Coder:============Binary Range Coder:-------------------The implemented range coder is an adapted version based upon"Range encoding: an algorithm for removing redundancy from a digitised message."by G.N.N.Martin.The symbols encoded by the Snow range coder are bits(0|1).The associated probabilities are not fix but change depending on the symbol mix seen so far.bit seen|new state---------+-----------------------------------------------0|256-state_transition_table[256-old_state];1|state_transition_table[old_state];state_transition_table={0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:-------------------------FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1.the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
Definition: snow.txt:206
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:471
uint32_t pal[256]
The currently-used palette data.
Definition: cdtoons.c:54
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:328
static int cdtoons_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: cdtoons.c:153
int active
Definition: cdtoons.c:47
int
common internal api header.
uint32_t size
Definition: cdtoons.c:45
uint16_t end_frame
Definition: cdtoons.c:43
#define MKBETAG(a, b, c, d)
Definition: common.h:406
void * priv_data
Definition: avcodec.h:558
uint16_t start_frame
Definition: cdtoons.c:42
uint8_t * data
Definition: cdtoons.c:46
#define av_freep(p)
AVFrame * frame
Definition: cdtoons.c:51
uint16_t last_pal_id
The index of the active palette sprite.
Definition: cdtoons.c:53
static int cdtoons_render_sprite(AVCodecContext *avctx, const uint8_t *data, uint32_t data_size, int dst_x, int dst_y, int width, int height)
Definition: cdtoons.c:58
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
static double val(void *priv, double ch)
Definition: aeval.c:76
This structure stores compressed data.
Definition: packet.h:340
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:50
int i
Definition: input.c:407
trying all byte sequences megabyte in length and selecting the best looking sequence will yield cases to try But a word about which is also called distortion Distortion can be quantified by almost any quality measurement one chooses the sum of squared differences is used but more complex methods that consider psychovisual effects can be used as well It makes no difference in this discussion First step
static av_cold int cdtoons_decode_init(AVCodecContext *avctx)
Definition: cdtoons.c:409