FFmpeg
xxan.c
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1 /*
2  * Wing Commander/Xan Video Decoder
3  * Copyright (C) 2011 Konstantin Shishkov
4  * based on work by Mike Melanson
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "libavutil/intreadwrite.h"
24 #include "libavutil/mem.h"
25 
26 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "internal.h"
29 
30 typedef struct XanContext {
33 
38 } XanContext;
39 
41 {
42  XanContext *s = avctx->priv_data;
43 
44  av_frame_free(&s->pic);
45 
46  av_freep(&s->y_buffer);
48 
49  return 0;
50 }
51 
53 {
54  XanContext *s = avctx->priv_data;
55 
56  s->avctx = avctx;
57 
58  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
59 
60  if (avctx->height < 8) {
61  av_log(avctx, AV_LOG_ERROR, "Invalid frame height: %d.\n", avctx->height);
62  return AVERROR(EINVAL);
63  }
64  if (avctx->width & 1) {
65  av_log(avctx, AV_LOG_ERROR, "Invalid frame width: %d.\n", avctx->width);
66  return AVERROR(EINVAL);
67  }
68 
69  s->buffer_size = avctx->width * avctx->height;
71  if (!s->y_buffer)
72  return AVERROR(ENOMEM);
73  s->scratch_buffer = av_malloc(s->buffer_size + 130);
74  if (!s->scratch_buffer) {
75  xan_decode_end(avctx);
76  return AVERROR(ENOMEM);
77  }
78 
79  s->pic = av_frame_alloc();
80  if (!s->pic) {
81  xan_decode_end(avctx);
82  return AVERROR(ENOMEM);
83  }
84 
85  return 0;
86 }
87 
89  uint8_t *dst, const int dst_size)
90 {
91  int tree_size, eof;
92  int bits, mask;
93  int tree_root, node;
94  const uint8_t *dst_end = dst + dst_size;
95  GetByteContext tree = s->gb;
96  int start_off = bytestream2_tell(&tree);
97 
98  tree_size = bytestream2_get_byte(&s->gb);
99  eof = bytestream2_get_byte(&s->gb);
100  tree_root = eof + tree_size;
101  bytestream2_skip(&s->gb, tree_size * 2);
102 
103  node = tree_root;
104  bits = bytestream2_get_byte(&s->gb);
105  mask = 0x80;
106  for (;;) {
107  int bit = !!(bits & mask);
108  mask >>= 1;
109  bytestream2_seek(&tree, start_off + node*2 + bit - eof * 2, SEEK_SET);
110  node = bytestream2_get_byte(&tree);
111  if (node == eof)
112  break;
113  if (node < eof) {
114  *dst++ = node;
115  if (dst > dst_end)
116  break;
117  node = tree_root;
118  }
119  if (!mask) {
120  if (bytestream2_get_bytes_left(&s->gb) <= 0)
121  break;
122  bits = bytestream2_get_byteu(&s->gb);
123  mask = 0x80;
124  }
125  }
126  return dst != dst_end ? AVERROR_INVALIDDATA : 0;
127 }
128 
129 /* almost the same as in xan_wc3 decoder */
130 static int xan_unpack(XanContext *s,
131  uint8_t *dest, const int dest_len)
132 {
133  uint8_t opcode;
134  int size;
135  uint8_t *orig_dest = dest;
136  const uint8_t *dest_end = dest + dest_len;
137 
138  while (dest < dest_end) {
139  if (bytestream2_get_bytes_left(&s->gb) <= 0)
140  return AVERROR_INVALIDDATA;
141 
142  opcode = bytestream2_get_byteu(&s->gb);
143 
144  if (opcode < 0xe0) {
145  int size2, back;
146  if ((opcode & 0x80) == 0) {
147  size = opcode & 3;
148  back = ((opcode & 0x60) << 3) + bytestream2_get_byte(&s->gb) + 1;
149  size2 = ((opcode & 0x1c) >> 2) + 3;
150  } else if ((opcode & 0x40) == 0) {
151  size = bytestream2_peek_byte(&s->gb) >> 6;
152  back = (bytestream2_get_be16(&s->gb) & 0x3fff) + 1;
153  size2 = (opcode & 0x3f) + 4;
154  } else {
155  size = opcode & 3;
156  back = ((opcode & 0x10) << 12) + bytestream2_get_be16(&s->gb) + 1;
157  size2 = ((opcode & 0x0c) << 6) + bytestream2_get_byte(&s->gb) + 5;
158  if (size + size2 > dest_end - dest)
159  break;
160  }
161  if (dest + size + size2 > dest_end ||
162  dest - orig_dest + size < back)
163  return AVERROR_INVALIDDATA;
164  bytestream2_get_buffer(&s->gb, dest, size);
165  dest += size;
166  av_memcpy_backptr(dest, back, size2);
167  dest += size2;
168  } else {
169  int finish = opcode >= 0xfc;
170 
171  size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
172  if (dest_end - dest < size)
173  return AVERROR_INVALIDDATA;
174  bytestream2_get_buffer(&s->gb, dest, size);
175  dest += size;
176  if (finish)
177  break;
178  }
179  }
180  return dest - orig_dest;
181 }
182 
183 static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
184 {
185  XanContext *s = avctx->priv_data;
186  uint8_t *U, *V;
187  int val, uval, vval;
188  int i, j;
189  const uint8_t *src, *src_end;
190  const uint8_t *table;
191  int mode, offset, dec_size, table_size;
192 
193  if (!chroma_off)
194  return 0;
195  if (chroma_off + 4 >= bytestream2_get_bytes_left(&s->gb)) {
196  av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
197  return AVERROR_INVALIDDATA;
198  }
199  bytestream2_seek(&s->gb, chroma_off + 4, SEEK_SET);
200  mode = bytestream2_get_le16(&s->gb);
201  table = s->gb.buffer;
202  table_size = bytestream2_get_le16(&s->gb);
203  offset = table_size * 2;
204  table_size += 1;
205 
206  if (offset >= bytestream2_get_bytes_left(&s->gb)) {
207  av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
208  return AVERROR_INVALIDDATA;
209  }
210 
211  bytestream2_skip(&s->gb, offset);
212  memset(s->scratch_buffer, 0, s->buffer_size);
213  dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size);
214  if (dec_size < 0) {
215  av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
216  return dec_size;
217  }
218 
219  U = s->pic->data[1];
220  V = s->pic->data[2];
221  src = s->scratch_buffer;
222  src_end = src + dec_size;
223  if (mode) {
224  for (j = 0; j < avctx->height >> 1; j++) {
225  for (i = 0; i < avctx->width >> 1; i++) {
226  if (src_end - src < 1)
227  return 0;
228  val = *src++;
229  if (val) {
230  if (val >= table_size)
231  return AVERROR_INVALIDDATA;
232  val = AV_RL16(table + (val << 1));
233  uval = (val >> 3) & 0xF8;
234  vval = (val >> 8) & 0xF8;
235  U[i] = uval | (uval >> 5);
236  V[i] = vval | (vval >> 5);
237  }
238  }
239  U += s->pic->linesize[1];
240  V += s->pic->linesize[2];
241  }
242  if (avctx->height & 1) {
243  memcpy(U, U - s->pic->linesize[1], avctx->width >> 1);
244  memcpy(V, V - s->pic->linesize[2], avctx->width >> 1);
245  }
246  } else {
247  uint8_t *U2 = U + s->pic->linesize[1];
248  uint8_t *V2 = V + s->pic->linesize[2];
249 
250  for (j = 0; j < avctx->height >> 2; j++) {
251  for (i = 0; i < avctx->width >> 1; i += 2) {
252  if (src_end - src < 1)
253  return 0;
254  val = *src++;
255  if (val) {
256  if (val >= table_size)
257  return AVERROR_INVALIDDATA;
258  val = AV_RL16(table + (val << 1));
259  uval = (val >> 3) & 0xF8;
260  vval = (val >> 8) & 0xF8;
261  U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
262  V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
263  }
264  }
265  U += s->pic->linesize[1] * 2;
266  V += s->pic->linesize[2] * 2;
267  U2 += s->pic->linesize[1] * 2;
268  V2 += s->pic->linesize[2] * 2;
269  }
270  if (avctx->height & 3) {
271  int lines = ((avctx->height + 1) >> 1) - (avctx->height >> 2) * 2;
272 
273  memcpy(U, U - lines * s->pic->linesize[1], lines * s->pic->linesize[1]);
274  memcpy(V, V - lines * s->pic->linesize[2], lines * s->pic->linesize[2]);
275  }
276  }
277 
278  return 0;
279 }
280 
282 {
283  XanContext *s = avctx->priv_data;
284  uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
285  unsigned chroma_off, corr_off;
286  int cur, last;
287  int i, j;
288  int ret;
289 
290  chroma_off = bytestream2_get_le32(&s->gb);
291  corr_off = bytestream2_get_le32(&s->gb);
292 
293  if ((ret = xan_decode_chroma(avctx, chroma_off)) != 0)
294  return ret;
295 
296  if (corr_off >= bytestream2_size(&s->gb)) {
297  av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
298  corr_off = 0;
299  }
300  bytestream2_seek(&s->gb, 12, SEEK_SET);
301  ret = xan_unpack_luma(s, src, s->buffer_size >> 1);
302  if (ret) {
303  av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
304  return ret;
305  }
306 
307  ybuf = s->y_buffer;
308  last = *src++;
309  ybuf[0] = last << 1;
310  for (j = 1; j < avctx->width - 1; j += 2) {
311  cur = (last + *src++) & 0x1F;
312  ybuf[j] = last + cur;
313  ybuf[j+1] = cur << 1;
314  last = cur;
315  }
316  ybuf[j] = last << 1;
317  prev_buf = ybuf;
318  ybuf += avctx->width;
319 
320  for (i = 1; i < avctx->height; i++) {
321  last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
322  ybuf[0] = last << 1;
323  for (j = 1; j < avctx->width - 1; j += 2) {
324  cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
325  ybuf[j] = last + cur;
326  ybuf[j+1] = cur << 1;
327  last = cur;
328  }
329  ybuf[j] = last << 1;
330  prev_buf = ybuf;
331  ybuf += avctx->width;
332  }
333 
334  if (corr_off) {
335  int dec_size;
336 
337  bytestream2_seek(&s->gb, 8 + corr_off, SEEK_SET);
338  dec_size = xan_unpack(s, s->scratch_buffer, s->buffer_size / 2);
339  if (dec_size < 0)
340  dec_size = 0;
341  else
342  dec_size = FFMIN(dec_size, s->buffer_size/2 - 1);
343 
344  for (i = 0; i < dec_size; i++)
345  s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
346  }
347 
348  src = s->y_buffer;
349  ybuf = s->pic->data[0];
350  for (j = 0; j < avctx->height; j++) {
351  for (i = 0; i < avctx->width; i++)
352  ybuf[i] = (src[i] << 2) | (src[i] >> 3);
353  src += avctx->width;
354  ybuf += s->pic->linesize[0];
355  }
356 
357  return 0;
358 }
359 
361 {
362  XanContext *s = avctx->priv_data;
363  uint8_t *ybuf, *src = s->scratch_buffer;
364  int cur, last;
365  int i, j;
366  int ret;
367 
368  if ((ret = xan_decode_chroma(avctx, bytestream2_get_le32(&s->gb))) != 0)
369  return ret;
370 
371  bytestream2_seek(&s->gb, 16, SEEK_SET);
372  ret = xan_unpack_luma(s, src,
373  s->buffer_size >> 1);
374  if (ret) {
375  av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
376  return ret;
377  }
378 
379  ybuf = s->y_buffer;
380  for (i = 0; i < avctx->height; i++) {
381  last = (ybuf[0] + (*src++ << 1)) & 0x3F;
382  ybuf[0] = last;
383  for (j = 1; j < avctx->width - 1; j += 2) {
384  cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
385  ybuf[j] = (last + cur) >> 1;
386  ybuf[j+1] = cur;
387  last = cur;
388  }
389  ybuf[j] = last;
390  ybuf += avctx->width;
391  }
392 
393  src = s->y_buffer;
394  ybuf = s->pic->data[0];
395  for (j = 0; j < avctx->height; j++) {
396  for (i = 0; i < avctx->width; i++)
397  ybuf[i] = (src[i] << 2) | (src[i] >> 3);
398  src += avctx->width;
399  ybuf += s->pic->linesize[0];
400  }
401 
402  return 0;
403 }
404 
406  void *data, int *got_frame,
407  AVPacket *avpkt)
408 {
409  XanContext *s = avctx->priv_data;
410  int ftype;
411  int ret;
412 
413  if ((ret = ff_reget_buffer(avctx, s->pic, 0)) < 0)
414  return ret;
415 
416  bytestream2_init(&s->gb, avpkt->data, avpkt->size);
417  ftype = bytestream2_get_le32(&s->gb);
418  switch (ftype) {
419  case 0:
420  ret = xan_decode_frame_type0(avctx);
421  break;
422  case 1:
423  ret = xan_decode_frame_type1(avctx);
424  break;
425  default:
426  av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
427  return AVERROR_INVALIDDATA;
428  }
429  if (ret)
430  return ret;
431 
432  if ((ret = av_frame_ref(data, s->pic)) < 0)
433  return ret;
434 
435  *got_frame = 1;
436 
437  return avpkt->size;
438 }
439 
441  .name = "xan_wc4",
442  .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
443  .type = AVMEDIA_TYPE_VIDEO,
444  .id = AV_CODEC_ID_XAN_WC4,
445  .priv_data_size = sizeof(XanContext),
447  .close = xan_decode_end,
449  .capabilities = AV_CODEC_CAP_DR1,
450 };
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
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
Memory handling functions.
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1484
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1781
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
AVCodec ff_xan_wc4_decoder
Definition: xxan.c:440
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3495
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
uint8_t
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
static int xan_decode_frame_type0(AVCodecContext *avctx)
Definition: xxan.c:281
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
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
static void finish(void)
Definition: movenc.c:345
uint8_t * data
Definition: avcodec.h:1483
const uint8_t * buffer
Definition: bytestream.h:34
void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
Overlapping memcpy() implementation.
Definition: mem.c:426
#define av_log(a,...)
static const uint16_t table[]
Definition: prosumer.c:206
static av_always_inline int bytestream2_size(GetByteContext *g)
Definition: bytestream.h:198
#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
static const uint16_t mask[17]
Definition: lzw.c:38
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:164
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#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:2015
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:154
const char * name
Name of the codec implementation.
Definition: avcodec.h:3502
uint8_t bits
Definition: vp3data.h:202
uint8_t * y_buffer
Definition: xxan.c:34
int size
Definition: xan.c:59
uint8_t * scratch_buffer
Definition: xxan.c:35
#define FFMIN(a, b)
Definition: common.h:96
int width
picture width / height.
Definition: avcodec.h:1744
static int xan_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: xxan.c:405
#define s(width, name)
Definition: cbs_vp9.c:257
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:188
static av_cold int xan_decode_end(AVCodecContext *avctx)
Definition: xxan.c:40
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:1571
Definition: xan.c:53
static int xan_unpack_luma(XanContext *s, uint8_t *dst, const int dst_size)
Definition: xxan.c:88
static av_cold int xan_decode_init(AVCodecContext *avctx)
Definition: xxan.c:52
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
int buffer_size
Definition: xxan.c:36
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
common internal api header.
#define bit(string, value)
Definition: cbs_mpeg2.c:58
static int xan_decode_frame_type1(AVCodecContext *avctx)
Definition: xxan.c:360
void * priv_data
Definition: avcodec.h:1598
static int xan_unpack(XanContext *s, uint8_t *dest, const int dest_len)
Definition: xxan.c:130
static av_always_inline int bytestream2_seek(GetByteContext *g, int offset, int whence)
Definition: bytestream.h:208
AVFrame * pic
Definition: xxan.c:32
#define av_freep(p)
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
GetByteContext gb
Definition: xxan.c:37
This structure stores compressed data.
Definition: avcodec.h:1460
mode
Use these values in ebur128_init (or&#39;ed).
Definition: ebur128.h:83
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:987
AVCodecContext * avctx
Definition: xan.c:55
static int xan_decode_chroma(AVCodecContext *avctx, unsigned chroma_off)
Definition: xxan.c:183
#define V
Definition: avdct.c:30