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/avassert.h"
26 #include "libavutil/imgutils.h"
27 #include "libavutil/avstring.h"
28 #include "avcodec.h"
29 #include "internal.h"
30 #include "pnm.h"
31 
pnm_space(int c)32 static inline int pnm_space(int c)
33 {
34     return c == ' ' || c == '\n' || c == '\r' || c == '\t';
35 }
36 
pnm_get(PNMContext * sc,char * str,int buf_size)37 static void pnm_get(PNMContext *sc, char *str, int buf_size)
38 {
39     char *s;
40     int c;
41     uint8_t *bs  = sc->bytestream;
42     const uint8_t *end = sc->bytestream_end;
43 
44     /* skip spaces and comments */
45     while (bs < end) {
46         c = *bs++;
47         if (c == '#')  {
48             while (c != '\n' && bs < end) {
49                 c = *bs++;
50             }
51         } else if (!pnm_space(c)) {
52             break;
53         }
54     }
55 
56     s = str;
57     while (bs < end && !pnm_space(c) && (s - str) < buf_size - 1) {
58         *s++ = c;
59         c = *bs++;
60     }
61     *s = '\0';
62     sc->bytestream = bs;
63 }
64 
ff_pnm_decode_header(AVCodecContext * avctx,PNMContext * const s)65 int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s)
66 {
67     char buf1[32], tuple_type[32];
68     int h, w, depth, maxval;
69     int ret;
70 
71     if (s->bytestream_end - s->bytestream < 3 ||
72         s->bytestream[0] != 'P' ||
73         (s->bytestream[1] < '1' ||
74          s->bytestream[1] > '7' &&
75          s->bytestream[1] != 'f' &&
76          s->bytestream[1] != 'F')) {
77         s->bytestream += s->bytestream_end > s->bytestream;
78         s->bytestream += s->bytestream_end > s->bytestream;
79         return AVERROR_INVALIDDATA;
80     }
81     pnm_get(s, buf1, sizeof(buf1));
82     s->type= buf1[1]-'0';
83 
84     if (buf1[1] == 'F') {
85         avctx->pix_fmt = AV_PIX_FMT_GBRPF32;
86     } else if (buf1[1] == 'f') {
87         avctx->pix_fmt = AV_PIX_FMT_GRAYF32;
88     } else if (s->type==1 || s->type==4) {
89         avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
90     } else if (s->type==2 || s->type==5) {
91         if (avctx->codec_id == AV_CODEC_ID_PGMYUV)
92             avctx->pix_fmt = AV_PIX_FMT_YUV420P;
93         else
94             avctx->pix_fmt = AV_PIX_FMT_GRAY8;
95     } else if (s->type==3 || s->type==6) {
96         avctx->pix_fmt = AV_PIX_FMT_RGB24;
97     } else if (s->type==7) {
98         w      = -1;
99         h      = -1;
100         maxval = -1;
101         depth  = -1;
102         tuple_type[0] = '\0';
103         for (;;) {
104             pnm_get(s, buf1, sizeof(buf1));
105             if (!strcmp(buf1, "WIDTH")) {
106                 pnm_get(s, buf1, sizeof(buf1));
107                 w = strtol(buf1, NULL, 10);
108             } else if (!strcmp(buf1, "HEIGHT")) {
109                 pnm_get(s, buf1, sizeof(buf1));
110                 h = strtol(buf1, NULL, 10);
111             } else if (!strcmp(buf1, "DEPTH")) {
112                 pnm_get(s, buf1, sizeof(buf1));
113                 depth = strtol(buf1, NULL, 10);
114             } else if (!strcmp(buf1, "MAXVAL")) {
115                 pnm_get(s, buf1, sizeof(buf1));
116                 maxval = strtol(buf1, NULL, 10);
117             } else if (!strcmp(buf1, "TUPLTYPE") ||
118                        /* libavcodec used to write invalid files */
119                        !strcmp(buf1, "TUPLETYPE")) {
120                 pnm_get(s, tuple_type, sizeof(tuple_type));
121             } else if (!strcmp(buf1, "ENDHDR")) {
122                 break;
123             } else {
124                 return AVERROR_INVALIDDATA;
125             }
126         }
127         if (!pnm_space(s->bytestream[-1]))
128             return AVERROR_INVALIDDATA;
129 
130         /* check that all tags are present */
131         if (w <= 0 || h <= 0 || maxval <= 0 || maxval > UINT16_MAX || depth <= 0 || tuple_type[0] == '\0' ||
132             av_image_check_size(w, h, 0, avctx) || s->bytestream >= s->bytestream_end)
133             return AVERROR_INVALIDDATA;
134 
135         ret = ff_set_dimensions(avctx, w, h);
136         if (ret < 0)
137             return ret;
138         s->maxval     = maxval;
139         if (depth == 1) {
140             if (maxval == 1) {
141                 avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
142             } else if (maxval < 256) {
143                 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
144             } else {
145                 avctx->pix_fmt = AV_PIX_FMT_GRAY16;
146             }
147         } else if (depth == 2) {
148             if (maxval < 256) {
149                 avctx->pix_fmt = AV_PIX_FMT_GRAY8A;
150             } else {
151                 avctx->pix_fmt = AV_PIX_FMT_YA16;
152             }
153         } else if (depth == 3) {
154             if (maxval < 256) {
155                 avctx->pix_fmt = AV_PIX_FMT_RGB24;
156             } else {
157                 avctx->pix_fmt = AV_PIX_FMT_RGB48;
158             }
159         } else if (depth == 4) {
160             if (maxval < 256) {
161                 avctx->pix_fmt = AV_PIX_FMT_RGBA;
162             } else {
163                 avctx->pix_fmt = AV_PIX_FMT_RGBA64;
164             }
165         } else {
166             return AVERROR_INVALIDDATA;
167         }
168         return 0;
169     } else {
170         av_assert0(0);
171     }
172     pnm_get(s, buf1, sizeof(buf1));
173     w = atoi(buf1);
174     pnm_get(s, buf1, sizeof(buf1));
175     h = atoi(buf1);
176     if(w <= 0 || h <= 0 || av_image_check_size(w, h, 0, avctx) || s->bytestream >= s->bytestream_end)
177         return AVERROR_INVALIDDATA;
178 
179     ret = ff_set_dimensions(avctx, w, h);
180     if (ret < 0)
181         return ret;
182 
183     if (avctx->pix_fmt == AV_PIX_FMT_GBRPF32 || avctx->pix_fmt == AV_PIX_FMT_GRAYF32) {
184         pnm_get(s, buf1, sizeof(buf1));
185         if (av_sscanf(buf1, "%f", &s->scale) != 1 || s->scale == 0.0 || !isfinite(s->scale)) {
186             av_log(avctx, AV_LOG_ERROR, "Invalid scale.\n");
187             return AVERROR_INVALIDDATA;
188         }
189         s->endian = s->scale < 0.f;
190         s->scale = fabsf(s->scale);
191         s->maxval = (1ULL << 32) - 1;
192     } else if (avctx->pix_fmt != AV_PIX_FMT_MONOWHITE && avctx->pix_fmt != AV_PIX_FMT_MONOBLACK) {
193         pnm_get(s, buf1, sizeof(buf1));
194         s->maxval = atoi(buf1);
195         if (s->maxval <= 0 || s->maxval > UINT16_MAX) {
196             av_log(avctx, AV_LOG_ERROR, "Invalid maxval: %d\n", s->maxval);
197             s->maxval = 255;
198         }
199         if (s->maxval >= 256) {
200             if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
201                 avctx->pix_fmt = AV_PIX_FMT_GRAY16;
202             } else if (avctx->pix_fmt == AV_PIX_FMT_RGB24) {
203                 avctx->pix_fmt = AV_PIX_FMT_RGB48;
204             } else if (avctx->pix_fmt == AV_PIX_FMT_YUV420P && s->maxval < 65536) {
205                 if (s->maxval < 512)
206                     avctx->pix_fmt = AV_PIX_FMT_YUV420P9;
207                 else if (s->maxval < 1024)
208                     avctx->pix_fmt = AV_PIX_FMT_YUV420P10;
209                 else
210                     avctx->pix_fmt = AV_PIX_FMT_YUV420P16;
211             } else {
212                 av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format\n");
213                 avctx->pix_fmt = AV_PIX_FMT_NONE;
214                 return AVERROR_INVALIDDATA;
215             }
216         }
217     }else
218         s->maxval=1;
219 
220     if (!pnm_space(s->bytestream[-1]))
221         return AVERROR_INVALIDDATA;
222 
223     /* more check if YUV420 */
224     if ((av_pix_fmt_desc_get(avctx->pix_fmt)->flags & AV_PIX_FMT_FLAG_PLANAR) &&
225         avctx->pix_fmt != AV_PIX_FMT_GBRPF32) {
226         if ((avctx->width & 1) != 0)
227             return AVERROR_INVALIDDATA;
228         h = (avctx->height * 2);
229         if ((h % 3) != 0)
230             return AVERROR_INVALIDDATA;
231         h /= 3;
232         avctx->height = h;
233     }
234     return 0;
235 }
236