FFmpeg
cdtoons.c
Go to the documentation of this file.
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  /* read new sprites introduced in this frame */
194  buf = avpkt->data + sprite_offset;
195  while (sprite_count--) {
196  uint32_t size;
197  uint16_t sprite_id;
198 
199  if (buf + 14 > eod)
200  return AVERROR_INVALIDDATA;
201 
202  sprite_id = bytestream_get_be16(&buf);
203  if (sprite_id >= CDTOONS_MAX_SPRITES) {
204  av_log(avctx, AV_LOG_ERROR,
205  "Sprite ID %d is too high.\n", sprite_id);
206  return AVERROR_INVALIDDATA;
207  }
208  if (c->sprites[sprite_id].active) {
209  av_log(avctx, AV_LOG_ERROR,
210  "Sprite ID %d is a duplicate.\n", sprite_id);
211  return AVERROR_INVALIDDATA;
212  }
213 
214  c->sprites[sprite_id].flags = bytestream_get_be16(&buf);
215  size = bytestream_get_be32(&buf);
216  if (size < 14) {
217  av_log(avctx, AV_LOG_ERROR,
218  "Sprite only has %d bytes of data.\n", size);
219  return AVERROR_INVALIDDATA;
220  }
221  size -= 14;
222  c->sprites[sprite_id].size = size;
223  c->sprites[sprite_id].owner_frame = frame_id;
224  c->sprites[sprite_id].start_frame = bytestream_get_be16(&buf);
225  c->sprites[sprite_id].end_frame = bytestream_get_be16(&buf);
226  buf += 2;
227 
228  if (size > buf_size || buf + size > eod)
229  return AVERROR_INVALIDDATA;
230 
231  av_fast_padded_malloc(&c->sprites[sprite_id].data, &c->sprites[sprite_id].alloc_size, size);
232  if (!c->sprites[sprite_id].data)
233  return AVERROR(ENOMEM);
234 
235  c->sprites[sprite_id].active = 1;
236 
237  bytestream_get_buffer(&buf, c->sprites[sprite_id].data, size);
238  }
239 
240  /* render any embedded sprites */
241  while (buf < eod) {
242  uint32_t tag, size;
243  if (buf + 8 > eod) {
244  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for embedded sprites.\n");
245  return AVERROR_INVALIDDATA;
246  }
247  tag = bytestream_get_be32(&buf);
248  size = bytestream_get_be32(&buf);
249  if (tag == MKBETAG('D', 'i', 'f', 'f')) {
250  uint16_t diff_count;
251  if (buf + 10 > eod) {
252  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame.\n");
253  return AVERROR_INVALIDDATA;
254  }
255  diff_count = bytestream_get_be16(&buf);
256  buf += 8; /* clip rect? */
257  for (int i = 0; i < diff_count; i++) {
258  int16_t top, left;
259  uint16_t diff_size, width, height;
260 
261  if (buf + 16 > eod) {
262  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame header.\n");
263  return AVERROR_INVALIDDATA;
264  }
265 
266  top = bytestream_get_be16(&buf);
267  left = bytestream_get_be16(&buf);
268  buf += 4; /* bottom, right */
269  diff_size = bytestream_get_be32(&buf);
270  width = bytestream_get_be16(&buf);
271  height = bytestream_get_be16(&buf);
272  if (diff_size < 8 || diff_size - 4 > eod - buf) {
273  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data for Diff frame data.\n");
274  return AVERROR_INVALIDDATA;
275  }
276  if (cdtoons_render_sprite(avctx, buf + 4, diff_size - 8,
277  left, top, width, height)) {
278  av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
279  }
280  buf += diff_size - 4;
281  }
282  saw_embedded_sprites = 1;
283  } else {
284  /* we don't care about any other entries */
285  if (size < 8 || size - 8 > eod - buf) {
286  av_log(avctx, AV_LOG_WARNING, "Ran out of data for ignored entry (size %X, %d left).\n", size, (int)(eod - buf));
287  return AVERROR_INVALIDDATA;
288  }
289  buf += (size - 8);
290  }
291  }
292 
293  /* was an intra frame? */
294  if (saw_embedded_sprites)
295  goto done;
296 
297  /* render any referenced sprites */
298  buf = avpkt->data + CDTOONS_HEADER_SIZE;
299  eod = avpkt->data + sprite_offset;
300  for (int i = 0; i < referenced_count; i++) {
301  const uint8_t *block_data;
302  uint16_t sprite_id, width, height;
303  int16_t top, left, right;
304 
305  if (buf + 10 > eod) {
306  av_log(avctx, AV_LOG_WARNING, "Ran (seriously) out of data when rendering.\n");
307  return AVERROR_INVALIDDATA;
308  }
309 
310  sprite_id = bytestream_get_be16(&buf);
311  top = bytestream_get_be16(&buf);
312  left = bytestream_get_be16(&buf);
313  buf += 2; /* bottom */
314  right = bytestream_get_be16(&buf);
315 
316  if ((i == 0) && (sprite_id == 0)) {
317  /* clear background */
318  memset(c->frame->data[0], background_color,
319  c->frame->linesize[0] * avctx->height);
320  }
321 
322  if (!right)
323  continue;
324  if (sprite_id >= CDTOONS_MAX_SPRITES) {
325  av_log(avctx, AV_LOG_ERROR,
326  "Sprite ID %d is too high.\n", sprite_id);
327  return AVERROR_INVALIDDATA;
328  }
329 
330  block_data = c->sprites[sprite_id].data;
331  if (!c->sprites[sprite_id].active) {
332  /* this can happen when seeking around */
333  av_log(avctx, AV_LOG_WARNING, "Sprite %d is missing.\n", sprite_id);
334  continue;
335  }
336  if (c->sprites[sprite_id].size < 14) {
337  av_log(avctx, AV_LOG_ERROR, "Sprite %d is too small.\n", sprite_id);
338  continue;
339  }
340 
341  height = bytestream_get_be16(&block_data);
342  width = bytestream_get_be16(&block_data);
343  block_data += 10;
344  if (cdtoons_render_sprite(avctx, block_data,
345  c->sprites[sprite_id].size - 14,
346  left, top, width, height)) {
347  av_log(avctx, AV_LOG_WARNING, "Ran beyond end of sprite while rendering.\n");
348  }
349  }
350 
351  if (palette_id && (palette_id != c->last_pal_id)) {
352  if (palette_id >= CDTOONS_MAX_SPRITES) {
353  av_log(avctx, AV_LOG_ERROR,
354  "Palette ID %d is too high.\n", palette_id);
355  return AVERROR_INVALIDDATA;
356  }
357  if (!c->sprites[palette_id].active) {
358  /* this can happen when seeking around */
359  av_log(avctx, AV_LOG_WARNING,
360  "Palette ID %d is missing.\n", palette_id);
361  goto done;
362  }
363  if (c->sprites[palette_id].size != 256 * 2 * 3) {
364  av_log(avctx, AV_LOG_ERROR,
365  "Palette ID %d is wrong size (%d).\n",
366  palette_id, c->sprites[palette_id].size);
367  return AVERROR_INVALIDDATA;
368  }
369  c->last_pal_id = palette_id;
370  if (!palette_set) {
371  uint8_t *palette_data = c->sprites[palette_id].data;
372  for (int i = 0; i < 256; i++) {
373  /* QuickTime-ish palette: 16-bit RGB components */
374  unsigned r, g, b;
375  r = *palette_data;
376  g = *(palette_data + 2);
377  b = *(palette_data + 4);
378  c->pal[i] = (0xFFU << 24) | (r << 16) | (g << 8) | b;
379  palette_data += 6;
380  }
381  /* first palette entry indicates transparency */
382  c->pal[0] = 0;
383  c->frame->palette_has_changed = 1;
384  }
385  }
386 
387 done:
388  /* discard outdated blocks */
389  for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
390  if (c->sprites[i].end_frame > frame_id)
391  continue;
392  c->sprites[i].active = 0;
393  }
394 
395  memcpy(c->frame->data[1], c->pal, AVPALETTE_SIZE);
396 
397  if ((ret = av_frame_ref(data, c->frame)) < 0)
398  return ret;
399 
400  *got_frame = 1;
401 
402  /* always report that the buffer was completely consumed */
403  return buf_size;
404 }
405 
407 {
408  CDToonsContext *c = avctx->priv_data;
409 
410  avctx->pix_fmt = AV_PIX_FMT_PAL8;
411  c->last_pal_id = 0;
412  c->frame = av_frame_alloc();
413  if (!c->frame)
414  return AVERROR(ENOMEM);
415 
416  return 0;
417 }
418 
419 static void cdtoons_flush(AVCodecContext *avctx)
420 {
421  CDToonsContext *c = avctx->priv_data;
422 
423  c->last_pal_id = 0;
424  for (int i = 0; i < CDTOONS_MAX_SPRITES; i++)
425  c->sprites[i].active = 0;
426 }
427 
429 {
430  CDToonsContext *c = avctx->priv_data;
431 
432  for (int i = 0; i < CDTOONS_MAX_SPRITES; i++) {
433  av_freep(&c->sprites[i].data);
434  c->sprites[i].active = 0;
435  }
436 
437  av_frame_free(&c->frame);
438 
439  return 0;
440 }
441 
443  .name = "cdtoons",
444  .long_name = NULL_IF_CONFIG_SMALL("CDToons video"),
445  .type = AVMEDIA_TYPE_VIDEO,
446  .id = AV_CODEC_ID_CDTOONS,
447  .priv_data_size = sizeof(CDToonsContext),
449  .close = cdtoons_decode_end,
451  .capabilities = AV_CODEC_CAP_DR1,
452  .flush = cdtoons_flush,
453 };
const char const char void * val
Definition: avisynth_c.h:863
#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:295
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:182
const char * g
Definition: vf_curves.c:115
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1534
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1831
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:70
static av_cold int cdtoons_decode_end(AVCodecContext *avctx)
Definition: cdtoons.c:428
AVCodec.
Definition: avcodec.h:3555
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:82
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:90
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:444
#define height
uint8_t * data
Definition: avcodec.h:1533
uint32_t tag
Definition: movenc.c:1534
ptrdiff_t size
Definition: opengl_enc.c:100
#define av_log(a,...)
#define U(x)
Definition: vp56_arith.h:37
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
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:186
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:2016
const char * r
Definition: vf_curves.c:114
const char * name
Name of the codec implementation.
Definition: avcodec.h:3562
AVCodec ff_cdtoons_decoder
Definition: cdtoons.c:442
#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:1794
static void cdtoons_flush(AVCodecContext *avctx)
Definition: cdtoons.c:419
static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b, uint8_t *dst, unsigned int size)
Definition: bytestream.h:359
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
main external API structure.
Definition: avcodec.h:1621
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
void * buf
Definition: avisynth_c.h:766
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:452
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:309
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:367
void * priv_data
Definition: avcodec.h:1648
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
This structure stores compressed data.
Definition: avcodec.h:1510
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:999
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:406