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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/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[1] != 'H' &&
78          s->bytestream[1] != 'h')) {
79         s->bytestream += s->bytestream_end > s->bytestream;
80         s->bytestream += s->bytestream_end > s->bytestream;
81         return AVERROR_INVALIDDATA;
82     }
83     pnm_get(s, buf1, sizeof(buf1));
84     s->type= buf1[1]-'0';
85     s->half = 0;
86 
87     if (buf1[1] == 'F') {
88         avctx->pix_fmt = AV_PIX_FMT_GBRPF32;
89     } else if (buf1[1] == 'f') {
90         avctx->pix_fmt = AV_PIX_FMT_GRAYF32;
91     } else if (buf1[1] == 'H') {
92         avctx->pix_fmt = AV_PIX_FMT_GBRPF32;
93         s->half = 1;
94     } else if (buf1[1] == 'h') {
95         avctx->pix_fmt = AV_PIX_FMT_GRAYF32;
96         s->half = 1;
97     } else if (s->type==1 || s->type==4) {
98         avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
99     } else if (s->type==2 || s->type==5) {
100         if (avctx->codec_id == AV_CODEC_ID_PGMYUV)
101             avctx->pix_fmt = AV_PIX_FMT_YUV420P;
102         else
103             avctx->pix_fmt = AV_PIX_FMT_GRAY8;
104     } else if (s->type==3 || s->type==6) {
105         avctx->pix_fmt = AV_PIX_FMT_RGB24;
106     } else if (s->type==7) {
107         w      = -1;
108         h      = -1;
109         maxval = -1;
110         depth  = -1;
111         tuple_type[0] = '\0';
112         for (;;) {
113             pnm_get(s, buf1, sizeof(buf1));
114             if (!strcmp(buf1, "WIDTH")) {
115                 pnm_get(s, buf1, sizeof(buf1));
116                 w = strtol(buf1, NULL, 10);
117             } else if (!strcmp(buf1, "HEIGHT")) {
118                 pnm_get(s, buf1, sizeof(buf1));
119                 h = strtol(buf1, NULL, 10);
120             } else if (!strcmp(buf1, "DEPTH")) {
121                 pnm_get(s, buf1, sizeof(buf1));
122                 depth = strtol(buf1, NULL, 10);
123             } else if (!strcmp(buf1, "MAXVAL")) {
124                 pnm_get(s, buf1, sizeof(buf1));
125                 maxval = strtol(buf1, NULL, 10);
126             } else if (!strcmp(buf1, "TUPLTYPE") ||
127                        /* libavcodec used to write invalid files */
128                        !strcmp(buf1, "TUPLETYPE")) {
129                 pnm_get(s, tuple_type, sizeof(tuple_type));
130             } else if (!strcmp(buf1, "ENDHDR")) {
131                 break;
132             } else {
133                 return AVERROR_INVALIDDATA;
134             }
135         }
136         if (!pnm_space(s->bytestream[-1]))
137             return AVERROR_INVALIDDATA;
138 
139         /* check that all tags are present */
140         if (w <= 0 || h <= 0 || maxval <= 0 || maxval > UINT16_MAX || depth <= 0 || tuple_type[0] == '\0' ||
141             av_image_check_size(w, h, 0, avctx) || s->bytestream >= s->bytestream_end)
142             return AVERROR_INVALIDDATA;
143 
144         ret = ff_set_dimensions(avctx, w, h);
145         if (ret < 0)
146             return ret;
147         s->maxval     = maxval;
148         if (depth == 1) {
149             if (maxval == 1) {
150                 avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
151             } else if (maxval < 256) {
152                 avctx->pix_fmt = AV_PIX_FMT_GRAY8;
153             } else {
154                 avctx->pix_fmt = AV_PIX_FMT_GRAY16;
155             }
156         } else if (depth == 2) {
157             if (maxval < 256) {
158                 avctx->pix_fmt = AV_PIX_FMT_GRAY8A;
159             } else {
160                 avctx->pix_fmt = AV_PIX_FMT_YA16;
161             }
162         } else if (depth == 3) {
163             if (maxval < 256) {
164                 avctx->pix_fmt = AV_PIX_FMT_RGB24;
165             } else {
166                 avctx->pix_fmt = AV_PIX_FMT_RGB48;
167             }
168         } else if (depth == 4) {
169             if (maxval < 256) {
170                 avctx->pix_fmt = AV_PIX_FMT_RGBA;
171             } else {
172                 avctx->pix_fmt = AV_PIX_FMT_RGBA64;
173             }
174         } else {
175             return AVERROR_INVALIDDATA;
176         }
177         return 0;
178     } else {
179         av_assert0(0);
180     }
181     pnm_get(s, buf1, sizeof(buf1));
182     w = atoi(buf1);
183     pnm_get(s, buf1, sizeof(buf1));
184     h = atoi(buf1);
185     if(w <= 0 || h <= 0 || av_image_check_size(w, h, 0, avctx) || s->bytestream >= s->bytestream_end)
186         return AVERROR_INVALIDDATA;
187 
188     ret = ff_set_dimensions(avctx, w, h);
189     if (ret < 0)
190         return ret;
191 
192     if (avctx->pix_fmt == AV_PIX_FMT_GBRPF32 || avctx->pix_fmt == AV_PIX_FMT_GRAYF32) {
193         pnm_get(s, buf1, sizeof(buf1));
194         if (av_sscanf(buf1, "%f", &s->scale) != 1 || s->scale == 0.0 || !isfinite(s->scale)) {
195             av_log(avctx, AV_LOG_ERROR, "Invalid scale.\n");
196             return AVERROR_INVALIDDATA;
197         }
198         s->endian = s->scale < 0.f;
199         s->scale = fabsf(s->scale);
200         s->maxval = (1ULL << 32) - 1;
201     } else if (avctx->pix_fmt != AV_PIX_FMT_MONOWHITE && avctx->pix_fmt != AV_PIX_FMT_MONOBLACK) {
202         pnm_get(s, buf1, sizeof(buf1));
203         s->maxval = atoi(buf1);
204         if (s->maxval <= 0 || s->maxval > UINT16_MAX) {
205             av_log(avctx, AV_LOG_ERROR, "Invalid maxval: %d\n", s->maxval);
206             s->maxval = 255;
207         }
208         if (s->maxval >= 256) {
209             if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
210                 avctx->pix_fmt = AV_PIX_FMT_GRAY16;
211             } else if (avctx->pix_fmt == AV_PIX_FMT_RGB24) {
212                 avctx->pix_fmt = AV_PIX_FMT_RGB48;
213             } else if (avctx->pix_fmt == AV_PIX_FMT_YUV420P && s->maxval < 65536) {
214                 if (s->maxval < 512)
215                     avctx->pix_fmt = AV_PIX_FMT_YUV420P9;
216                 else if (s->maxval < 1024)
217                     avctx->pix_fmt = AV_PIX_FMT_YUV420P10;
218                 else
219                     avctx->pix_fmt = AV_PIX_FMT_YUV420P16;
220             } else {
221                 av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format\n");
222                 avctx->pix_fmt = AV_PIX_FMT_NONE;
223                 return AVERROR_INVALIDDATA;
224             }
225         }
226     }else
227         s->maxval=1;
228 
229     if (!pnm_space(s->bytestream[-1]))
230         return AVERROR_INVALIDDATA;
231 
232     /* more check if YUV420 */
233     if ((av_pix_fmt_desc_get(avctx->pix_fmt)->flags & AV_PIX_FMT_FLAG_PLANAR) &&
234         avctx->pix_fmt != AV_PIX_FMT_GBRPF32) {
235         if ((avctx->width & 1) != 0)
236             return AVERROR_INVALIDDATA;
237         h = (avctx->height * 2);
238         if ((h % 3) != 0)
239             return AVERROR_INVALIDDATA;
240         h /= 3;
241         avctx->height = h;
242     }
243     return 0;
244 }
245