FFmpeg
gemdec.c
Go to the documentation of this file.
1 /*
2  * GEM Raster image decoder
3  * Copyright (c) 2021 Peter Ross (pross@xvid.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  * GEM Raster image decoder
25  */
26 
27 #include "avcodec.h"
28 #include "bytestream.h"
29 #include "internal.h"
30 
31 static const uint32_t gem_color_palette[16]={
32  0xFFFFFFFF, 0xFFFF0000, 0xFF00FF00, 0xFFFFFF00,
33  0xFF0000FF, 0xFFFF00FF, 0xFF00FFFF, 0xFFAEAEAE,
34  0xFF555555, 0xFFAE0000, 0xFF00AE00, 0xFFAEAE00,
35  0xFF0000AE, 0xFFAE00AE, 0xFF00AEAE, 0xFF000000,
36 };
37 
38 static const uint8_t gem_gray[256]={
39  0xFF, 0x7F, 0xBF, 0x3F, 0xDF, 0x5F, 0x9F, 0x1F, 0xEF, 0x6F, 0xAF, 0x2F, 0xCF, 0x4F, 0x8F, 0x0F,
40  0xF7, 0x77, 0xB7, 0x37, 0xD7, 0x57, 0x97, 0x17, 0xE7, 0x67, 0xA7, 0x27, 0xC7, 0x47, 0x87, 0x07,
41  0xFB, 0x7B, 0xBB, 0x3B, 0xDB, 0x5B, 0x9B, 0x1B, 0xEB, 0x6B, 0xAB, 0x2B, 0xCB, 0x4B, 0x8B, 0x0B,
42  0xF3, 0x73, 0xB3, 0x33, 0xD3, 0x53, 0x93, 0x13, 0xE3, 0x63, 0xA3, 0x23, 0xC3, 0x43, 0x83, 0x03,
43  0xFD, 0x7D, 0xBD, 0x3D, 0xDD, 0x5D, 0x9D, 0x1D, 0xED, 0x6D, 0xAD, 0x2D, 0xCD, 0x4D, 0x8D, 0x0D,
44  0xF5, 0x75, 0xB5, 0x35, 0xD5, 0x55, 0x95, 0x15, 0xE5, 0x65, 0xA5, 0x25, 0xC5, 0x45, 0x85, 0x05,
45  0xF9, 0x79, 0xB9, 0x39, 0xD9, 0x59, 0x99, 0x19, 0xE9, 0x69, 0xA9, 0x29, 0xC9, 0x49, 0x89, 0x09,
46  0xF1, 0x71, 0xB1, 0x31, 0xD1, 0x51, 0x91, 0x11, 0xE1, 0x61, 0xA1, 0x21, 0xC1, 0x41, 0x81, 0x01,
47  0xFE, 0x7E, 0xBE, 0x3E, 0xDE, 0x5E, 0x9E, 0x1E, 0xEE, 0x6E, 0xAE, 0x2E, 0xCE, 0x4E, 0x8E, 0x0E,
48  0xF6, 0x76, 0xB6, 0x36, 0xD6, 0x56, 0x96, 0x16, 0xE6, 0x66, 0xA6, 0x26, 0xC6, 0x46, 0x86, 0x06,
49  0xFA, 0x7A, 0xBA, 0x3A, 0xDA, 0x5A, 0x9A, 0x1A, 0xEA, 0x6A, 0xAA, 0x2A, 0xCA, 0x4A, 0x8A, 0x0A,
50  0xF2, 0x72, 0xB2, 0x32, 0xD2, 0x52, 0x92, 0x12, 0xE2, 0x62, 0xA2, 0x22, 0xC2, 0x42, 0x82, 0x02,
51  0xFC, 0x7C, 0xBC, 0x3C, 0xDC, 0x5C, 0x9C, 0x1C, 0xEC, 0x6C, 0xAC, 0x2C, 0xCC, 0x4C, 0x8C, 0x0C,
52  0xF4, 0x74, 0xB4, 0x34, 0xD4, 0x54, 0x94, 0x14, 0xE4, 0x64, 0xA4, 0x24, 0xC4, 0x44, 0x84, 0x04,
53  0xF8, 0x78, 0xB8, 0x38, 0xD8, 0x58, 0x98, 0x18, 0xE8, 0x68, 0xA8, 0x28, 0xC8, 0x48, 0x88, 0x08,
54  0xF0, 0x70, 0xB0, 0x30, 0xD0, 0x50, 0x90, 0x10, 0xE0, 0x60, 0xA0, 0x20, 0xC0, 0x40, 0x80, 0x00,
55 };
56 
57 typedef struct {
58  int y, pl, x, vdup;
59 } State;
60 
61 static void put_lines_bits(AVCodecContext *avctx, int planes, int row_width, int pixel_size, State * state, uint8_t * row, AVFrame *p)
62 {
63  int pl_byte = state->pl / 8;
64  int pl_bit = state->pl & 7;
65  for (int y = 0; y < state->vdup && (state->y + y) < avctx->height; y++)
66  for (int x = 0; x < row_width; x++)
67  for (int i = 7; i >= 0 && x * 8 + 7 - i < avctx->width; i--)
68  p->data[0][ (state->y + y) * p->linesize[0] + (x * 8 + 7 - i) * pixel_size + pl_byte] |= !!(row[x] & (1 << i)) << pl_bit;
69 
70  state->pl++;
71  if (state->pl >= planes) {
72  state->pl = 0;
73  state->y += state->vdup;
74  state->vdup = 1;
75  }
76 }
77 
78 static void put_lines_bytes(AVCodecContext *avctx, int planes, int row_width, int pixel_size, State * state, uint8_t * row, AVFrame *p)
79 {
80  for (int y = 0; y < state->vdup && (state->y + y) < avctx->height; y++)
81  memcpy(p->data[0] + (state->y + y) * p->linesize[0], row, avctx->width * pixel_size);
82 
83  state->y += state->vdup;
84  state->vdup = 1;
85 }
86 
87 static int gem_decode_frame(AVCodecContext *avctx,
88  void *data, int *got_frame,
89  AVPacket *avpkt)
90 {
91  const uint8_t *buf = avpkt->data;
92  int buf_size = avpkt->size;
93  const uint8_t *buf_end = buf + buf_size;
94  AVFrame *p = data;
95  int header_size, planes, pattern_size, tag = 0, count_scalar = 1, ret;
96  unsigned int x, count, v;
97  GetByteContext gb;
98  uint32_t *palette;
99  const uint8_t * b;
100  uint8_t * row;
101  int row_width, pixel_size;
102  State state = {.y = 0, .pl = 0, .x = 0, .vdup = 1};
103  void (*put_lines)(AVCodecContext *avctx, int planes, int row_width, int pixel_size, State * state, uint8_t * row, AVFrame *p);
104  int width, height;
105 
106  if (buf_size <= 16)
107  return AVERROR_INVALIDDATA;
108 
109  bytestream2_init(&gb, buf + 2, buf_size - 2);
110  header_size = bytestream2_get_be16(&gb);
111  if (header_size < 8 || buf_size <= header_size * 2)
112  return AVERROR_INVALIDDATA;
113 
114  planes = bytestream2_get_be16(&gb);
115  pattern_size = bytestream2_get_be16(&gb);
116  avctx->sample_aspect_ratio.num = bytestream2_get_be16(&gb);
117  avctx->sample_aspect_ratio.den = bytestream2_get_be16(&gb);
118  width = bytestream2_get_be16(&gb);
119  height = bytestream2_get_be16(&gb);
120  ret = ff_set_dimensions(avctx, width, height);
121  if (ret < 0)
122  return ret;
123 
124  row_width = (avctx->width + 7) / 8;
125  put_lines = put_lines_bits;
126 
127  if (header_size == 9) {
128  count_scalar = bytestream2_get_be16(&gb);
129  if (count_scalar != 3) {
130  avpriv_request_sample(avctx, "count_scalar=%d", count_scalar);
131  return AVERROR_PATCHWELCOME;
132  }
133  planes = 24;
134  avctx->pix_fmt = AV_PIX_FMT_BGR24;
135  pixel_size = 3;
136  } else if (planes == 15) {
137 #if HAVE_BIGENDIAN
138  avctx->pix_fmt = AV_PIX_FMT_BGR555BE;
139 #else
140  avctx->pix_fmt = AV_PIX_FMT_BGR555LE;
141 #endif
142  pixel_size = 2;
143  } else if (planes == 16) {
144  avctx->pix_fmt = AV_PIX_FMT_RGB565BE;
145  pixel_size = 2;
146  } else if (planes == 24) {
147  avctx->pix_fmt = AV_PIX_FMT_RGB24;
148  pixel_size = 3;
149  } else if (planes == 32) {
150  avctx->pix_fmt = AV_PIX_FMT_0RGB;
151  pixel_size = 4;
152  } else {
153  avctx->pix_fmt = AV_PIX_FMT_PAL8;
154  pixel_size = 1;
155  }
156 
157  if (header_size >= 11)
158  tag = bytestream2_peek_be32(&gb);
159 
160  if (tag == AV_RB32("STTT")) {
161  if (planes != 4) {
162  avpriv_request_sample(avctx, "STTT planes=%d", planes);
163  return AVERROR_PATCHWELCOME;
164  }
165  } else if (tag == AV_RB32("TIMG")) {
166  if (planes != 15) {
167  avpriv_request_sample(avctx, "TIMG planes=%d", planes);
168  return AVERROR_PATCHWELCOME;
169  }
170  } else if (tag == AV_RB32("XIMG")) {
171  if (planes != 1 && planes != 2 && planes != 4 && planes != 8 && planes != 16 && planes != 24 && planes != 32) {
172  avpriv_request_sample(avctx, "XIMG planes=%d", planes);
173  return AVERROR_PATCHWELCOME;
174  }
175  } else if (planes != 1 && planes != 2 && planes != 3 && planes != 4 && planes != 8 && planes != 16 && planes != 24) {
176  avpriv_request_sample(avctx, "planes=%d", planes);
177  return AVERROR_PATCHWELCOME;
178  }
179 
180  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
181  return ret;
182 
184  p->key_frame = 1;
185  p->palette_has_changed = 1;
186  palette = (uint32_t *)p->data[1];
187 
188  if (tag == AV_RB32("STTT")) {
189  bytestream2_skip(&gb, 6);
190  if (planes == 4) {
191  for (int i = 0; i < (1 << planes); i++) {
192  int v = bytestream2_get_be16(&gb);
193  int r = ((v >> 8) & 0x7) << 5;
194  int g = ((v >> 4) & 0x7) << 5;
195  int b = ((v ) & 0x7) << 5;
196  palette[i] = 0xFF000000 | r << 16 | g << 8 | b;
197  }
198  } else {
199  av_assert0(0);
200  }
201  } else if (tag == AV_RB32("TIMG")) {
202  bytestream2_skip(&gb, 4);
203  if (planes != 15) {
204  av_assert0(0);
205  }
206  } else if (tag == AV_RB32("XIMG")) {
207  bytestream2_skip(&gb, 6);
208  if (planes == 1 || planes == 2 || planes == 4 || planes == 8) {
209  for (int i = 0; i < (1 << planes); i++) {
210  int r = (bytestream2_get_be16(&gb) * 51 + 100) / 200;
211  int g = (bytestream2_get_be16(&gb) * 51 + 100) / 200;
212  int b = (bytestream2_get_be16(&gb) * 51 + 100) / 200;
213  palette[i] = 0xFF000000 | r << 16 | g << 8 | b;
214  }
215  } else if (planes == 16) {
216  planes = 1;
217  row_width = ((avctx->width + 7)/8)*8 * pixel_size;
218  put_lines = put_lines_bytes;
219  } else if (planes == 24) {
220  planes = 1;
221  row_width = ((avctx->width + 15)/16)*16 * pixel_size;
222  put_lines = put_lines_bytes;
223  } else if (planes == 32) {
224  planes = 1;
225  row_width = avctx->width * pixel_size;
226  put_lines = put_lines_bytes;
227  } else {
228  av_assert0(0);
229  }
230  } else if (planes == 1) {
231  palette[0] = 0xFFFFFFFF;
232  palette[1] = 0xFF000000;
233  } else if (planes == 2 || planes == 3 || planes == 4) {
234  if (header_size == 9 + (1 << planes)) {
235  bytestream2_skip(&gb, 2);
236  for (int i = 0; i < (1 << planes); i++) {
237  int v = bytestream2_get_be16(&gb);
238  int r = ((v >> 8) & 0x7) << 5;
239  int g = ((v >> 4) & 0x7) << 5;
240  int b = ((v ) & 0x7) << 5;
241  palette[i] = 0xFF000000 | r << 16 | g << 8 | b;
242  }
243  } else
244  memcpy(palette, gem_color_palette, sizeof(gem_color_palette));
245  } else if (planes == 8) {
246  for (int i = 0; i < 256; i++)
247  palette[i] = 0xFF000000 | (gem_gray[i]<<16) | (gem_gray[i]<<8) | gem_gray[i];
248  } else if (planes == 16) {
249  planes = 1;
250  row_width = avctx->width * pixel_size;
251  put_lines = put_lines_bytes;
252  } else if (planes == 24) {
253  planes = 1;
254  row_width = avctx->width * pixel_size;
255  put_lines = put_lines_bytes;
256  } else
257  av_assert0(0);
258 
259  ret = av_reallocp_array(&avctx->priv_data, planes, row_width);
260  if (ret < 0)
261  return ret;
262  row = avctx->priv_data;
263 
264  memset(p->data[0], 0, avctx->height * p->linesize[0]);
265  b = buf + header_size * 2;
266  x = 0;
267 
268 #define SKIP \
269 do { \
270  x++; \
271  if (x >= row_width) { \
272  put_lines(avctx, planes, row_width, pixel_size, &state, row + state.pl * row_width, p); \
273  if (state.y >= avctx->height) goto abort; \
274  x = 0; \
275  } \
276 } while(0)
277 
278 #define PUT(v) \
279 do { \
280  row[state.pl * row_width + x++] = v; \
281  if (x >= row_width) { \
282  put_lines(avctx, planes, row_width, pixel_size, &state, row + state.pl * row_width, p); \
283  if (state.y >= avctx->height) goto abort; \
284  x = 0; \
285  } \
286 } while(0)
287 
288  while(b < buf_end) {
289  int opcode = *b++;
290  if (opcode == 0x80) { /* copy */
291  if (b >= buf_end)
292  goto abort;
293  count = *b++;
294  if (!count)
295  count = 256;
296  count *= count_scalar;
297  for (int j = 0; j < count; j++) {
298  if (b >= buf_end)
299  goto abort;
300  PUT(*b++);
301  }
302  } else if (opcode) { /* run */
303  count = opcode & 0x7f;
304  if (!count)
305  count = 256;
306  count *= count_scalar;
307  v = opcode & 0x80 ? 0xFF : 0x00;
308  for (int i = 0; i < count; i++)
309  PUT(v);
310  } else {
311  if (b >= buf_end)
312  goto abort;
313  count = *b++;
314  if (count) { /* pattern */
315  if (b > buf_end - pattern_size)
316  goto abort;
317 
318  count *= count_scalar;
319  for (int j = 0; j < count; j++)
320  for (int k = 0; k < pattern_size; k++)
321  PUT(b[k]);
322 
323  b += pattern_size;
324  } else {
325  if (b >= buf_end)
326  goto abort;
327  count = *b++;
328  if (count == 0xFF) { /* vertical duplication */
329  if (b >= buf_end)
330  goto abort;
331  state.vdup = *b++;
332  if (!state.vdup)
333  state.vdup = 256;
334  } else { /* horizontal duplication */
335  for (int i = 0; i < count + 1; i++)
336  SKIP;
337  }
338  }
339  }
340  }
341 
342 abort:
343 
344  *got_frame = 1;
345  return buf_size;
346 }
347 
348 static av_cold int gem_close(AVCodecContext *avctx)
349 {
350  av_freep(&avctx->priv_data);
351  return 0;
352 }
353 
355  .name = "gem",
356  .long_name = NULL_IF_CONFIG_SMALL("GEM Raster image"),
357  .type = AVMEDIA_TYPE_VIDEO,
358  .id = AV_CODEC_ID_GEM,
359  .decode = gem_decode_frame,
360  .close = gem_close,
361  .capabilities = AV_CODEC_CAP_DR1,
362 };
AVCodec
AVCodec.
Definition: codec.h:202
r
const char * r
Definition: vf_curves.c:116
GetByteContext
Definition: bytestream.h:33
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:310
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
b
#define b
Definition: input.c:40
data
const char data[16]
Definition: mxf.c:143
gem_decode_frame
static int gem_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: gemdec.c:87
AV_PIX_FMT_BGR24
@ AV_PIX_FMT_BGR24
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:331
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
gem_gray
static const uint8_t gem_gray[256]
Definition: gemdec.c:38
PUT
#define PUT(v)
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:402
AVRational::num
int num
Numerator.
Definition: rational.h:59
av_cold
#define av_cold
Definition: attributes.h:90
gem_color_palette
static const uint32_t gem_color_palette[16]
Definition: gemdec.c:31
width
#define width
put_lines_bits
static void put_lines_bits(AVCodecContext *avctx, int planes, int row_width, int pixel_size, State *state, uint8_t *row, AVFrame *p)
Definition: gemdec.c:61
g
const char * g
Definition: vf_curves.c:117
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
planes
static const struct @321 planes[]
if
if(ret)
Definition: filter_design.txt:179
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
AV_PIX_FMT_BGR555BE
@ AV_PIX_FMT_BGR555BE
packed BGR 5:5:5, 16bpp, (msb)1X 5B 5G 5R(lsb), big-endian , X=unused/undefined
Definition: pixfmt.h:112
State::y
int y
Definition: gemdec.c:58
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:407
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1649
AV_PIX_FMT_RGB24
@ AV_PIX_FMT_RGB24
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:68
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
state
static struct @320 state
AVPacket::size
int size
Definition: packet.h:374
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:117
ff_gem_decoder
const AVCodec ff_gem_decoder
Definition: gemdec.c:354
AV_RB32
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_RB32
Definition: bytestream.h:96
height
#define height
av_reallocp_array
int av_reallocp_array(void *ptr, size_t nmemb, size_t size)
Allocate, reallocate, or free an array through a pointer to a pointer.
Definition: mem.c:232
put_lines_bytes
static void put_lines_bytes(AVCodecContext *avctx, int planes, int row_width, int pixel_size, State *state, uint8_t *row, AVFrame *p)
Definition: gemdec.c:78
State
Definition: gemdec.c:57
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
AVCodecContext::height
int height
Definition: avcodec.h:556
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:593
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:1595
ret
ret
Definition: filter_design.txt:187
gem_close
static av_cold int gem_close(AVCodecContext *avctx)
Definition: gemdec.c:348
AVCodecContext
main external API structure.
Definition: avcodec.h:383
AVFrame::palette_has_changed
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:472
AVRational::den
int den
Denominator.
Definition: rational.h:60
AV_PIX_FMT_RGB565BE
@ AV_PIX_FMT_RGB565BE
packed RGB 5:6:5, 16bpp, (msb) 5R 6G 5B(lsb), big-endian
Definition: pixfmt.h:105
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
SKIP
#define SKIP
AV_CODEC_ID_GEM
@ AV_CODEC_ID_GEM
Definition: codec_id.h:310
ff_set_dimensions
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:86
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:37
AV_PIX_FMT_BGR555LE
@ AV_PIX_FMT_BGR555LE
packed BGR 5:5:5, 16bpp, (msb)1X 5B 5G 5R(lsb), little-endian, X=unused/undefined
Definition: pixfmt.h:113
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
AVPacket
This structure stores compressed data.
Definition: packet.h:350
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:556
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:355
AV_PIX_FMT_0RGB
@ AV_PIX_FMT_0RGB
packed RGB 8:8:8, 32bpp, XRGBXRGB... X=unused/undefined
Definition: pixfmt.h:227
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AVCodecContext::sample_aspect_ratio
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel.
Definition: avcodec.h:753