sgidec.c
Go to the documentation of this file.
1 /*
2  * SGI image decoder
3  * Todd Kirby <doubleshot@pacbell.net>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/imgutils.h"
23 #include "avcodec.h"
24 #include "bytestream.h"
25 #include "internal.h"
26 #include "sgi.h"
27 
28 typedef struct SgiState {
30  unsigned int width;
31  unsigned int height;
32  unsigned int depth;
33  unsigned int bytes_per_channel;
34  int linesize;
36 } SgiState;
37 
46 static int expand_rle_row(SgiState *s, uint8_t *out_buf,
47  uint8_t *out_end, int pixelstride)
48 {
49  unsigned char pixel, count;
50  unsigned char *orig = out_buf;
51 
52  while (1) {
53  if (bytestream2_get_bytes_left(&s->g) < 1)
54  return AVERROR_INVALIDDATA;
55  pixel = bytestream2_get_byteu(&s->g);
56  if (!(count = (pixel & 0x7f))) {
57  return (out_buf - orig) / pixelstride;
58  }
59 
60  /* Check for buffer overflow. */
61  if(out_buf + pixelstride * count >= out_end) return -1;
62 
63  if (pixel & 0x80) {
64  while (count--) {
65  *out_buf = bytestream2_get_byte(&s->g);
66  out_buf += pixelstride;
67  }
68  } else {
69  pixel = bytestream2_get_byte(&s->g);
70 
71  while (count--) {
72  *out_buf = pixel;
73  out_buf += pixelstride;
74  }
75  }
76  }
77 }
78 
85 static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
86 {
87  uint8_t *dest_row;
88  unsigned int len = s->height * s->depth * 4;
89  GetByteContext g_table = s->g;
90  unsigned int y, z;
91  unsigned int start_offset;
92 
93  /* size of RLE offset and length tables */
94  if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
95  return AVERROR_INVALIDDATA;
96  }
97 
98  for (z = 0; z < s->depth; z++) {
99  dest_row = out_buf;
100  for (y = 0; y < s->height; y++) {
101  dest_row -= s->linesize;
102  start_offset = bytestream2_get_be32(&g_table);
103  bytestream2_seek(&s->g, start_offset, SEEK_SET);
104  if (expand_rle_row(s, dest_row + z, dest_row + FFABS(s->linesize),
105  s->depth) != s->width) {
106  return AVERROR_INVALIDDATA;
107  }
108  }
109  }
110  return 0;
111 }
112 
120 static int read_uncompressed_sgi(unsigned char* out_buf, uint8_t* out_end,
121  SgiState *s)
122 {
123  int x, y, z;
124  unsigned int offset = s->height * s->width * s->bytes_per_channel;
125  GetByteContext gp[4];
126 
127  /* Test buffer size. */
128  if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
129  return AVERROR_INVALIDDATA;
130 
131  /* Create a reader for each plane */
132  for (z = 0; z < s->depth; z++) {
133  gp[z] = s->g;
134  bytestream2_skip(&gp[z], z * offset);
135  }
136 
137  for (y = s->height - 1; y >= 0; y--) {
138  out_end = out_buf + (y * s->linesize);
139  if (s->bytes_per_channel == 1) {
140  for (x = s->width; x > 0; x--)
141  for (z = 0; z < s->depth; z++)
142  *out_end++ = bytestream2_get_byteu(&gp[z]);
143  } else {
144  uint16_t *out16 = (uint16_t *)out_end;
145  for (x = s->width; x > 0; x--)
146  for (z = 0; z < s->depth; z++)
147  *out16++ = bytestream2_get_ne16u(&gp[z]);
148  }
149  }
150  return 0;
151 }
152 
153 static int decode_frame(AVCodecContext *avctx,
154  void *data, int *got_frame,
155  AVPacket *avpkt)
156 {
157  SgiState *s = avctx->priv_data;
158  AVFrame *picture = data;
159  AVFrame *p = &s->picture;
160  unsigned int dimension, rle;
161  int ret = 0;
162  uint8_t *out_buf, *out_end;
163 
164  bytestream2_init(&s->g, avpkt->data, avpkt->size);
166  av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
167  return AVERROR_INVALIDDATA;
168  }
169 
170  /* Test for SGI magic. */
171  if (bytestream2_get_be16(&s->g) != SGI_MAGIC) {
172  av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
173  return AVERROR_INVALIDDATA;
174  }
175 
176  rle = bytestream2_get_byte(&s->g);
177  s->bytes_per_channel = bytestream2_get_byte(&s->g);
178  dimension = bytestream2_get_be16(&s->g);
179  s->width = bytestream2_get_be16(&s->g);
180  s->height = bytestream2_get_be16(&s->g);
181  s->depth = bytestream2_get_be16(&s->g);
182 
183  if (s->bytes_per_channel != 1 && (s->bytes_per_channel != 2 || rle)) {
184  av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
185  return -1;
186  }
187 
188  /* Check for supported image dimensions. */
189  if (dimension != 2 && dimension != 3) {
190  av_log(avctx, AV_LOG_ERROR, "wrong dimension number\n");
191  return -1;
192  }
193 
194  if (s->depth == SGI_GRAYSCALE) {
196  } else if (s->depth == SGI_RGB) {
198  } else if (s->depth == SGI_RGBA && s->bytes_per_channel == 1) {
199  avctx->pix_fmt = AV_PIX_FMT_RGBA;
200  } else {
201  av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
202  return -1;
203  }
204 
205  if (av_image_check_size(s->width, s->height, 0, avctx))
206  return -1;
207  avcodec_set_dimensions(avctx, s->width, s->height);
208 
209  if (p->data[0])
210  avctx->release_buffer(avctx, p);
211 
212  p->reference = 0;
213  if (ff_get_buffer(avctx, p) < 0) {
214  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed.\n");
215  return -1;
216  }
217 
219  p->key_frame = 1;
220  out_buf = p->data[0];
221 
222  out_end = out_buf + p->linesize[0] * s->height;
223 
224  s->linesize = p->linesize[0];
225 
226  /* Skip header. */
227  bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
228  if (rle) {
229  ret = read_rle_sgi(out_end, s);
230  } else {
231  ret = read_uncompressed_sgi(out_buf, out_end, s);
232  }
233 
234  if (ret == 0) {
235  *picture = s->picture;
236  *got_frame = 1;
237  return avpkt->size;
238  } else {
239  return ret;
240  }
241 }
242 
243 static av_cold int sgi_init(AVCodecContext *avctx){
244  SgiState *s = avctx->priv_data;
245 
247  avctx->coded_frame = &s->picture;
248 
249  return 0;
250 }
251 
252 static av_cold int sgi_end(AVCodecContext *avctx)
253 {
254  SgiState * const s = avctx->priv_data;
255 
256  if (s->picture.data[0])
257  avctx->release_buffer(avctx, &s->picture);
258 
259  return 0;
260 }
261 
263  .name = "sgi",
264  .type = AVMEDIA_TYPE_VIDEO,
265  .id = AV_CODEC_ID_SGI,
266  .priv_data_size = sizeof(SgiState),
267  .init = sgi_init,
268  .close = sgi_end,
269  .decode = decode_frame,
270  .long_name = NULL_IF_CONFIG_SMALL("SGI image"),
271  .capabilities = CODEC_CAP_DR1,
272 };
static int expand_rle_row(SgiState *s, uint8_t *out_buf, uint8_t *out_end, int pixelstride)
Expand an RLE row into a channel.
Definition: sgidec.c:46
int linesize
Definition: sgidec.c:34
This structure describes decoded (raw) audio or video data.
Definition: avcodec.h:989
unsigned int width
Definition: sgidec.c:30
void(* release_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called to release buffers which were allocated with get_buffer.
Definition: avcodec.h:2259
misc image utilities
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:67
AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2725
void avcodec_set_dimensions(AVCodecContext *s, int width, int height)
Definition: utils.c:149
int size
Definition: avcodec.h:916
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1533
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:130
static int read_rle_sgi(uint8_t *out_buf, SgiState *s)
Read a run length encoded SGI image.
Definition: sgidec.c:85
unsigned int height
Definition: sgidec.c:31
AVCodec.
Definition: avcodec.h:2960
unsigned int bytes_per_channel
Definition: sgidec.c:33
struct SgiState SgiState
static av_cold int sgi_init(AVCodecContext *avctx)
Definition: sgidec.c:243
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
AVFrame picture
Definition: sgidec.c:29
uint8_t
const char data[16]
Definition: mxf.c:66
uint8_t * data
Definition: avcodec.h:915
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:335
static int read_uncompressed_sgi(unsigned char *out_buf, uint8_t *out_end, SgiState *s)
Read an uncompressed SGI image.
Definition: sgidec.c:120
int reference
is this picture used as reference The values for this are the same as the MpegEncContext.picture_structure variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
Definition: avcodec.h:1132
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:159
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:88
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:149
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:146
const char * name
Name of the codec implementation.
Definition: avcodec.h:2967
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:94
#define SGI_RGBA
Definition: sgi.h:34
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:220
unsigned int depth
Definition: sgidec.c:32
static AVFrame * picture
enum AVPictureType pict_type
Picture type of the frame, see ?_TYPE below.
Definition: avcodec.h:1065
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame)
Get a buffer for a frame.
Definition: utils.c:464
#define pixel
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: sgidec.c:153
external API header
int linesize[AV_NUM_DATA_POINTERS]
Size, in bytes, of the data for each picture/channel plane.
Definition: avcodec.h:1008
main external API structure.
Definition: avcodec.h:1339
#define SGI_HEADER_SIZE
Definition: sgi.h:30
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:326
void avcodec_get_frame_defaults(AVFrame *frame)
Set the fields of the given AVFrame to default values.
Definition: utils.c:602
Y , 16bpp, big-endian.
Definition: pixfmt.h:98
#define SGI_GRAYSCALE
Definition: sgi.h:32
#define SGI_RGB
Definition: sgi.h:33
GetByteContext g
Definition: sgidec.c:35
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
#define SGI_MAGIC
SGI image file signature.
Definition: sgi.h:28
#define bytestream2_get_ne16u
Definition: bytestream.h:116
Y , 8bpp.
Definition: pixfmt.h:73
common internal api header.
packed RGB 16:16:16, 48bpp, 16R, 16G, 16B, the 2-byte value for each R/G/B component is stored as big...
Definition: pixfmt.h:108
void * priv_data
Definition: avcodec.h:1382
int len
AVCodec ff_sgi_decoder
Definition: sgidec.c:262
int key_frame
1 -> keyframe, 0-> not
Definition: avcodec.h:1058
static av_always_inline int bytestream2_seek(GetByteContext *g, int offset, int whence)
Definition: bytestream.h:193
static av_cold int sgi_end(AVCodecContext *avctx)
Definition: sgidec.c:252
#define gp
Definition: regdef.h:62
This structure stores compressed data.
Definition: avcodec.h:898