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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 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 #include <stdlib.h>
23 #include <string.h>
24 
25 #include "libavutil/imgutils.h"
26 #include "avcodec.h"
27 #include "pnm.h"
28 
29 static inline int pnm_space(int c)
30 {
31  return c == ' ' || c == '\n' || c == '\r' || c == '\t';
32 }
33 
34 static void pnm_get(PNMContext *sc, char *str, int buf_size)
35 {
36  char *s;
37  int c;
38 
39  /* skip spaces and comments */
40  while (sc->bytestream < sc->bytestream_end) {
41  c = *sc->bytestream++;
42  if (c == '#') {
43  while (c != '\n' && sc->bytestream < sc->bytestream_end) {
44  c = *sc->bytestream++;
45  }
46  } else if (!pnm_space(c)) {
47  break;
48  }
49  }
50 
51  s = str;
52  while (sc->bytestream < sc->bytestream_end && !pnm_space(c)) {
53  if ((s - str) < buf_size - 1)
54  *s++ = c;
55  c = *sc->bytestream++;
56  }
57  *s = '\0';
58 }
59 
60 int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s)
61 {
62  char buf1[32], tuple_type[32];
63  int h, w, depth, maxval;
64 
65  pnm_get(s, buf1, sizeof(buf1));
66  if(buf1[0] != 'P')
67  return AVERROR_INVALIDDATA;
68  s->type= buf1[1]-'0';
69 
70  if (s->type==1 || s->type==4) {
71  avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
72  } else if (s->type==2 || s->type==5) {
73  if (avctx->codec_id == AV_CODEC_ID_PGMYUV)
74  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
75  else
76  avctx->pix_fmt = AV_PIX_FMT_GRAY8;
77  } else if (s->type==3 || s->type==6) {
78  avctx->pix_fmt = AV_PIX_FMT_RGB24;
79  } else if (s->type==7) {
80  w = -1;
81  h = -1;
82  maxval = -1;
83  depth = -1;
84  tuple_type[0] = '\0';
85  for (;;) {
86  pnm_get(s, buf1, sizeof(buf1));
87  if (!strcmp(buf1, "WIDTH")) {
88  pnm_get(s, buf1, sizeof(buf1));
89  w = strtol(buf1, NULL, 10);
90  } else if (!strcmp(buf1, "HEIGHT")) {
91  pnm_get(s, buf1, sizeof(buf1));
92  h = strtol(buf1, NULL, 10);
93  } else if (!strcmp(buf1, "DEPTH")) {
94  pnm_get(s, buf1, sizeof(buf1));
95  depth = strtol(buf1, NULL, 10);
96  } else if (!strcmp(buf1, "MAXVAL")) {
97  pnm_get(s, buf1, sizeof(buf1));
98  maxval = strtol(buf1, NULL, 10);
99  } else if (!strcmp(buf1, "TUPLTYPE") ||
100  /* libavcodec used to write invalid files */
101  !strcmp(buf1, "TUPLETYPE")) {
102  pnm_get(s, tuple_type, sizeof(tuple_type));
103  } else if (!strcmp(buf1, "ENDHDR")) {
104  break;
105  } else {
106  return AVERROR_INVALIDDATA;
107  }
108  }
109  /* check that all tags are present */
110  if (w <= 0 || h <= 0 || maxval <= 0 || depth <= 0 || tuple_type[0] == '\0' || av_image_check_size(w, h, 0, avctx) || s->bytestream >= s->bytestream_end)
111  return AVERROR_INVALIDDATA;
112 
113  avctx->width = w;
114  avctx->height = h;
115  s->maxval = maxval;
116  if (depth == 1) {
117  if (maxval == 1) {
118  avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
119  } else if (maxval < 256) {
120  avctx->pix_fmt = AV_PIX_FMT_GRAY8;
121  } else {
122  avctx->pix_fmt = AV_PIX_FMT_GRAY16;
123  }
124  } else if (depth == 2) {
125  if (maxval < 256) {
126  avctx->pix_fmt = AV_PIX_FMT_GRAY8A;
127  } else {
128  avctx->pix_fmt = AV_PIX_FMT_YA16;
129  }
130  } else if (depth == 3) {
131  if (maxval < 256) {
132  avctx->pix_fmt = AV_PIX_FMT_RGB24;
133  } else {
134  avctx->pix_fmt = AV_PIX_FMT_RGB48;
135  }
136  } else if (depth == 4) {
137  if (maxval < 256) {
138  avctx->pix_fmt = AV_PIX_FMT_RGBA;
139  } else {
140  avctx->pix_fmt = AV_PIX_FMT_RGBA64;
141  }
142  } else {
143  return AVERROR_INVALIDDATA;
144  }
145  return 0;
146  } else {
147  return AVERROR_INVALIDDATA;
148  }
149  pnm_get(s, buf1, sizeof(buf1));
150  w = atoi(buf1);
151  pnm_get(s, buf1, sizeof(buf1));
152  h = atoi(buf1);
153  if(w <= 0 || h <= 0 || av_image_check_size(w, h, 0, avctx) || s->bytestream >= s->bytestream_end)
154  return AVERROR_INVALIDDATA;
155 
156  avctx->width = w;
157  avctx->height = h;
158 
159  if (avctx->pix_fmt != AV_PIX_FMT_MONOWHITE && avctx->pix_fmt != AV_PIX_FMT_MONOBLACK) {
160  pnm_get(s, buf1, sizeof(buf1));
161  s->maxval = atoi(buf1);
162  if (s->maxval <= 0) {
163  av_log(avctx, AV_LOG_ERROR, "Invalid maxval: %d\n", s->maxval);
164  s->maxval = 255;
165  }
166  if (s->maxval >= 256) {
167  if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
168  avctx->pix_fmt = AV_PIX_FMT_GRAY16;
169  } else if (avctx->pix_fmt == AV_PIX_FMT_RGB24) {
170  avctx->pix_fmt = AV_PIX_FMT_RGB48;
171  } else if (avctx->pix_fmt == AV_PIX_FMT_YUV420P && s->maxval < 65536) {
172  if (s->maxval < 512)
173  avctx->pix_fmt = AV_PIX_FMT_YUV420P9;
174  else if (s->maxval < 1024)
175  avctx->pix_fmt = AV_PIX_FMT_YUV420P10;
176  else
177  avctx->pix_fmt = AV_PIX_FMT_YUV420P16;
178  } else {
179  av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format\n");
180  avctx->pix_fmt = AV_PIX_FMT_NONE;
181  return AVERROR_INVALIDDATA;
182  }
183  }
184  }else
185  s->maxval=1;
186  /* more check if YUV420 */
187  if (av_pix_fmt_desc_get(avctx->pix_fmt)->flags & AV_PIX_FMT_FLAG_PLANAR) {
188  if ((avctx->width & 1) != 0)
189  return AVERROR_INVALIDDATA;
190  h = (avctx->height * 2);
191  if ((h % 3) != 0)
192  return AVERROR_INVALIDDATA;
193  h /= 3;
194  avctx->height = h;
195  }
196  return 0;
197 }
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