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xbmdec.c
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1 /*
2  * XBM image format
3  *
4  * Copyright (c) 2012 Paul B Mahol
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/avstring.h"
24 
25 #include "avcodec.h"
26 #include "internal.h"
27 #include "mathops.h"
28 
29 static int convert(uint8_t x)
30 {
31  if (x >= 'a')
32  x -= 87;
33  else if (x >= 'A')
34  x -= 55;
35  else
36  x -= '0';
37  return x;
38 }
39 
40 static int parse_str_int(const uint8_t *p, int len, const uint8_t *key)
41 {
42  const uint8_t *end = p + len;
43 
44  for(; p<end - strlen(key); p++) {
45  if (!memcmp(p, key, strlen(key)))
46  break;
47  }
48  p += strlen(key);
49  if (p >= end)
50  return INT_MIN;
51 
52  for(; p<end; p++) {
53  char *eptr;
54  int64_t ret = strtol(p, &eptr, 10);
55  if ((const uint8_t *)eptr != p)
56  return ret;
57  }
58  return INT_MIN;
59 }
60 
61 static int xbm_decode_frame(AVCodecContext *avctx, void *data,
62  int *got_frame, AVPacket *avpkt)
63 {
64  AVFrame *p = data;
65  int ret, linesize, i, j;
66  int width = 0;
67  int height = 0;
68  const uint8_t *end, *ptr = avpkt->data;
69  const uint8_t *next;
70  uint8_t *dst;
71 
73  end = avpkt->data + avpkt->size;
74 
75  width = parse_str_int(avpkt->data, avpkt->size, "_width");
76  height = parse_str_int(avpkt->data, avpkt->size, "_height");
77 
78  if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
79  return ret;
80 
81  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
82  return ret;
83 
84  // goto start of image data
85  next = memchr(ptr, '{', avpkt->size);
86  if (!next)
87  next = memchr(ptr, '(', avpkt->size);
88  if (!next)
89  return AVERROR_INVALIDDATA;
90  ptr = next + 1;
91 
92  linesize = (avctx->width + 7) / 8;
93  for (i = 0; i < avctx->height; i++) {
94  dst = p->data[0] + i * p->linesize[0];
95  for (j = 0; j < linesize; j++) {
96  uint8_t val;
97 
98  while (ptr < end && *ptr != 'x' && *ptr != '$')
99  ptr++;
100 
101  ptr ++;
102  if (ptr < end && av_isxdigit(*ptr)) {
103  val = convert(*ptr++);
104  if (av_isxdigit(*ptr))
105  val = (val << 4) + convert(*ptr++);
106  *dst++ = ff_reverse[val];
107  if (av_isxdigit(*ptr) && j+1 < linesize) {
108  j++;
109  val = convert(*ptr++);
110  if (av_isxdigit(*ptr))
111  val = (val << 4) + convert(*ptr++);
112  *dst++ = ff_reverse[val];
113  }
114  } else {
115  av_log(avctx, AV_LOG_ERROR,
116  "Unexpected data at %.8s.\n", ptr);
117  return AVERROR_INVALIDDATA;
118  }
119  }
120  }
121 
122  p->key_frame = 1;
124 
125  *got_frame = 1;
126 
127  return avpkt->size;
128 }
129 
131  .name = "xbm",
132  .long_name = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"),
133  .type = AVMEDIA_TYPE_VIDEO,
134  .id = AV_CODEC_ID_XBM,
135  .decode = xbm_decode_frame,
136  .capabilities = AV_CODEC_CAP_DR1,
137 };
const char const char void * val
Definition: avisynth_c.h:634
#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:171
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
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:216
int size
Definition: avcodec.h:1423
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1721
AVCodec.
Definition: avcodec.h:3471
AVCodec ff_xbm_decoder
Definition: xbmdec.c:130
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
static int xbm_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: xbmdec.c:61
uint8_t * data
Definition: avcodec.h:1422
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
const uint8_t ff_reverse[256]
Definition: reverse.c:23
const char * name
Name of the codec implementation.
Definition: avcodec.h:3478
Libavcodec external API header.
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:242
int width
picture width / height.
Definition: avcodec.h:1680
static int convert(uint8_t x)
Definition: xbmdec.c:29
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:199
main external API structure.
Definition: avcodec.h:1501
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:1040
BYTE int const BYTE int int int height
Definition: avisynth_c.h:676
static int parse_str_int(const uint8_t *p, int len, const uint8_t *key)
Definition: xbmdec.c:40
int av_isxdigit(int c)
Locale-independent conversion of ASCII isxdigit.
Definition: avstring.c:336
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:182
common internal api header.
Y , 1bpp, 0 is white, 1 is black, in each byte pixels are ordered from the msb to the lsb...
Definition: pixfmt.h:72
int len
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:237
This structure stores compressed data.
Definition: avcodec.h:1399
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:856
static int width