libavcodec/pnm.c

   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 "avcodec.h"
  23 #include "pnm.h"
  24
  25 static inline int pnm_space(int c)
  26 {
  27     return c == ' ' || c == '\n' || c == '\r' || c == '\t';
  28 }
  29
  30 static void pnm_get(PNMContext *sc, char *str, int buf_size)
  31 {
  32     char *s;
  33     int c;
  34
  35     /* skip spaces and comments */
  36     for (;;) {
  37         c = *sc->bytestream++;
  38         if (c == '#')  {
  39             do {
  40                 c = *sc->bytestream++;
  41             } while (c != '\n' && sc->bytestream < sc->bytestream_end);
  42         } else if (!pnm_space(c)) {
  43             break;
  44         }
  45     }
  46
  47     s = str;
  48     while (sc->bytestream < sc->bytestream_end && !pnm_space(c)) {
  49         if ((s - str)  < buf_size - 1)
  50             *s++ = c;
  51         c = *sc->bytestream++;
  52     }
  53     *s = '\0';
  54 }
  55
  56 int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s)
  57 {
  58     char buf1[32], tuple_type[32];
  59     int h, w, depth, maxval;
  60
  61     pnm_get(s, buf1, sizeof(buf1));
  62     if (!strcmp(buf1, "P4")) {
  63         avctx->pix_fmt = PIX_FMT_MONOWHITE;
  64     } else if (!strcmp(buf1, "P5")) {
  65         if (avctx->codec_id == CODEC_ID_PGMYUV)
  66             avctx->pix_fmt = PIX_FMT_YUV420P;
  67         else
  68             avctx->pix_fmt = PIX_FMT_GRAY8;
  69     } else if (!strcmp(buf1, "P6")) {
  70         avctx->pix_fmt = PIX_FMT_RGB24;
  71     } else if (!strcmp(buf1, "P7")) {
  72         w      = -1;
  73         h      = -1;
  74         maxval = -1;
  75         depth  = -1;
  76         tuple_type[0] = '\0';
  77         for (;;) {
  78             pnm_get(s, buf1, sizeof(buf1));
  79             if (!strcmp(buf1, "WIDTH")) {
  80                 pnm_get(s, buf1, sizeof(buf1));
  81                 w = strtol(buf1, NULL, 10);
  82             } else if (!strcmp(buf1, "HEIGHT")) {
  83                 pnm_get(s, buf1, sizeof(buf1));
  84                 h = strtol(buf1, NULL, 10);
  85             } else if (!strcmp(buf1, "DEPTH")) {
  86                 pnm_get(s, buf1, sizeof(buf1));
  87                 depth = strtol(buf1, NULL, 10);
  88             } else if (!strcmp(buf1, "MAXVAL")) {
  89                 pnm_get(s, buf1, sizeof(buf1));
  90                 maxval = strtol(buf1, NULL, 10);
  91             } else if (!strcmp(buf1, "TUPLETYPE")) {
  92                 pnm_get(s, tuple_type, sizeof(tuple_type));
  93             } else if (!strcmp(buf1, "ENDHDR")) {
  94                 break;
  95             } else {
  96                 return -1;
  97             }
  98         }
  99         /* check that all tags are present */
 100         if (w <= 0 || h <= 0 || maxval <= 0 || depth <= 0 || tuple_type[0] == '\0' || avcodec_check_dimensions(avctx, w, h))
 101             return -1;
 102
 103         avctx->width  = w;
 104         avctx->height = h;
 105         if (depth == 1) {
 106             if (maxval == 1)
 107                 avctx->pix_fmt = PIX_FMT_MONOWHITE;
 108             else
 109                 avctx->pix_fmt = PIX_FMT_GRAY8;
 110         } else if (depth == 3) {
 111             if (maxval < 256) {
 112             avctx->pix_fmt = PIX_FMT_RGB24;
 113             } else {
 114                 av_log(avctx, AV_LOG_ERROR, "16-bit components are only supported for grayscale\n");
 115                 avctx->pix_fmt = PIX_FMT_NONE;
 116                 return -1;
 117             }
 118         } else if (depth == 4) {
 119             avctx->pix_fmt = PIX_FMT_RGB32;
 120         } else {
 121             return -1;
 122         }
 123         return 0;
 124     } else {
 125         return -1;
 126     }
 127     pnm_get(s, buf1, sizeof(buf1));
 128     avctx->width = atoi(buf1);
 129     if (avctx->width <= 0)
 130         return -1;
 131     pnm_get(s, buf1, sizeof(buf1));
 132     avctx->height = atoi(buf1);
 133     if(avcodec_check_dimensions(avctx, avctx->width, avctx->height))
 134         return -1;
 135     if (avctx->pix_fmt != PIX_FMT_MONOWHITE) {
 136         pnm_get(s, buf1, sizeof(buf1));
 137         s->maxval = atoi(buf1);
 138         if (s->maxval >= 256) {
 139             if (avctx->pix_fmt == PIX_FMT_GRAY8) {
 140                 avctx->pix_fmt = PIX_FMT_GRAY16BE;
 141                 if (s->maxval != 65535)
 142                     avctx->pix_fmt = PIX_FMT_GRAY16;
 143             } else if (avctx->pix_fmt == PIX_FMT_RGB24) {
 144                 if (s->maxval > 255)
 145                     avctx->pix_fmt = PIX_FMT_RGB48BE;
 146             } else {
 147                 av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format\n");
 148                 avctx->pix_fmt = PIX_FMT_NONE;
 149                 return -1;
 150             }
 151         }
 152     }
 153     /* more check if YUV420 */
 154     if (avctx->pix_fmt == PIX_FMT_YUV420P) {
 155         if ((avctx->width & 1) != 0)
 156             return -1;
 157         h = (avctx->height * 2);
 158         if ((h % 3) != 0)
 159             return -1;
 160         h /= 3;
 161         avctx->height = h;
 162     }
 163     return 0;
 164 }
 165
 166 av_cold int ff_pnm_end(AVCodecContext *avctx)
 167 {
 168     PNMContext *s = avctx->priv_data;
 169
 170     if (s->picture.data[0])
 171         avctx->release_buffer(avctx, &s->picture);
 172
 173     return 0;
 174 }
 175
 176 av_cold int ff_pnm_init(AVCodecContext *avctx)
 177 {
 178     PNMContext *s = avctx->priv_data;
 179
 180     avcodec_get_frame_defaults((AVFrame*)&s->picture);
 181     avctx->coded_frame = (AVFrame*)&s->picture;
 182
 183     return 0;
 184 }