pnm.c
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1 /*
2  * PNM image format
3  * Copyright (c) 2002, 2003 Fabrice Bellard
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 "pnm.h"
25 
26 static inline int pnm_space(int c)
27 {
28  return c == ' ' || c == '\n' || c == '\r' || c == '\t';
29 }
30 
31 static void pnm_get(PNMContext *sc, char *str, int buf_size)
32 {
33  char *s;
34  int c;
35 
36  /* skip spaces and comments */
37  for (;;) {
38  c = *sc->bytestream++;
39  if (c == '#') {
40  do {
41  c = *sc->bytestream++;
42  } while (c != '\n' && sc->bytestream < sc->bytestream_end);
43  } else if (!pnm_space(c)) {
44  break;
45  }
46  }
47 
48  s = str;
49  while (sc->bytestream < sc->bytestream_end && !pnm_space(c)) {
50  if ((s - str) < buf_size - 1)
51  *s++ = c;
52  c = *sc->bytestream++;
53  }
54  *s = '\0';
55 }
56 
58 {
59  char buf1[32], tuple_type[32];
60  int h, w, depth, maxval;
61 
62  pnm_get(s, buf1, sizeof(buf1));
63  s->type= buf1[1]-'0';
64  if(buf1[0] != 'P')
65  return -1;
66 
67  if (s->type==1 || s->type==4) {
68  avctx->pix_fmt = PIX_FMT_MONOWHITE;
69  } else if (s->type==2 || s->type==5) {
70  if (avctx->codec_id == CODEC_ID_PGMYUV)
71  avctx->pix_fmt = PIX_FMT_YUV420P;
72  else
73  avctx->pix_fmt = PIX_FMT_GRAY8;
74  } else if (s->type==3 || s->type==6) {
75  avctx->pix_fmt = PIX_FMT_RGB24;
76  } else if (s->type==7) {
77  w = -1;
78  h = -1;
79  maxval = -1;
80  depth = -1;
81  tuple_type[0] = '\0';
82  for (;;) {
83  pnm_get(s, buf1, sizeof(buf1));
84  if (!strcmp(buf1, "WIDTH")) {
85  pnm_get(s, buf1, sizeof(buf1));
86  w = strtol(buf1, NULL, 10);
87  } else if (!strcmp(buf1, "HEIGHT")) {
88  pnm_get(s, buf1, sizeof(buf1));
89  h = strtol(buf1, NULL, 10);
90  } else if (!strcmp(buf1, "DEPTH")) {
91  pnm_get(s, buf1, sizeof(buf1));
92  depth = strtol(buf1, NULL, 10);
93  } else if (!strcmp(buf1, "MAXVAL")) {
94  pnm_get(s, buf1, sizeof(buf1));
95  maxval = strtol(buf1, NULL, 10);
96  } else if (!strcmp(buf1, "TUPLETYPE")) {
97  pnm_get(s, tuple_type, sizeof(tuple_type));
98  } else if (!strcmp(buf1, "ENDHDR")) {
99  break;
100  } else {
101  return -1;
102  }
103  }
104  /* check that all tags are present */
105  if (w <= 0 || h <= 0 || maxval <= 0 || depth <= 0 || tuple_type[0] == '\0' || av_image_check_size(w, h, 0, avctx))
106  return -1;
107 
108  avctx->width = w;
109  avctx->height = h;
110  if (depth == 1) {
111  if (maxval == 1)
112  avctx->pix_fmt = PIX_FMT_MONOWHITE;
113  else
114  avctx->pix_fmt = PIX_FMT_GRAY8;
115  } else if (depth == 3) {
116  if (maxval < 256) {
117  avctx->pix_fmt = PIX_FMT_RGB24;
118  } else {
119  av_log(avctx, AV_LOG_ERROR, "16-bit components are only supported for grayscale\n");
120  avctx->pix_fmt = PIX_FMT_NONE;
121  return -1;
122  }
123  } else if (depth == 4) {
124  avctx->pix_fmt = PIX_FMT_RGB32;
125  } else {
126  return -1;
127  }
128  return 0;
129  } else {
130  return -1;
131  }
132  pnm_get(s, buf1, sizeof(buf1));
133  avctx->width = atoi(buf1);
134  if (avctx->width <= 0)
135  return -1;
136  pnm_get(s, buf1, sizeof(buf1));
137  avctx->height = atoi(buf1);
138  if(av_image_check_size(avctx->width, avctx->height, 0, avctx))
139  return -1;
140  if (avctx->pix_fmt != PIX_FMT_MONOWHITE) {
141  pnm_get(s, buf1, sizeof(buf1));
142  s->maxval = atoi(buf1);
143  if (s->maxval <= 0) {
144  av_log(avctx, AV_LOG_ERROR, "Invalid maxval: %d\n", s->maxval);
145  s->maxval = 255;
146  }
147  if (s->maxval >= 256) {
148  if (avctx->pix_fmt == PIX_FMT_GRAY8) {
149  avctx->pix_fmt = PIX_FMT_GRAY16BE;
150  if (s->maxval != 65535)
151  avctx->pix_fmt = PIX_FMT_GRAY16;
152  } else if (avctx->pix_fmt == PIX_FMT_RGB24) {
153  if (s->maxval > 255)
154  avctx->pix_fmt = PIX_FMT_RGB48BE;
155  } else {
156  av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format\n");
157  avctx->pix_fmt = PIX_FMT_NONE;
158  return -1;
159  }
160  }
161  }else
162  s->maxval=1;
163  /* more check if YUV420 */
164  if (avctx->pix_fmt == PIX_FMT_YUV420P) {
165  if ((avctx->width & 1) != 0)
166  return -1;
167  h = (avctx->height * 2);
168  if ((h % 3) != 0)
169  return -1;
170  h /= 3;
171  avctx->height = h;
172  }
173  return 0;
174 }
175 
177 {
178  PNMContext *s = avctx->priv_data;
179 
180  if (s->picture.data[0])
181  avctx->release_buffer(avctx, &s->picture);
182 
183  return 0;
184 }
185 
187 {
188  PNMContext *s = avctx->priv_data;
189 
191  avctx->coded_frame = (AVFrame*)&s->picture;
192 
193  return 0;
194 }