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libavcodec/pnm.c

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00001 /*
00002  * PNM image format
00003  * Copyright (c) 2002, 2003 Fabrice Bellard
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavutil/imgutils.h"
00023 #include "avcodec.h"
00024 #include "pnm.h"
00025 
00026 static inline int pnm_space(int c)
00027 {
00028     return c == ' ' || c == '\n' || c == '\r' || c == '\t';
00029 }
00030 
00031 static void pnm_get(PNMContext *sc, char *str, int buf_size)
00032 {
00033     char *s;
00034     int c;
00035 
00036     /* skip spaces and comments */
00037     for (;;) {
00038         c = *sc->bytestream++;
00039         if (c == '#')  {
00040             do {
00041                 c = *sc->bytestream++;
00042             } while (c != '\n' && sc->bytestream < sc->bytestream_end);
00043         } else if (!pnm_space(c)) {
00044             break;
00045         }
00046     }
00047 
00048     s = str;
00049     while (sc->bytestream < sc->bytestream_end && !pnm_space(c)) {
00050         if ((s - str)  < buf_size - 1)
00051             *s++ = c;
00052         c = *sc->bytestream++;
00053     }
00054     *s = '\0';
00055 }
00056 
00057 int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s)
00058 {
00059     char buf1[32], tuple_type[32];
00060     int h, w, depth, maxval;
00061 
00062     pnm_get(s, buf1, sizeof(buf1));
00063     s->type= buf1[1]-'0';
00064     if(buf1[0] != 'P')
00065         return -1;
00066 
00067     if (s->type==1 || s->type==4) {
00068         avctx->pix_fmt = PIX_FMT_MONOWHITE;
00069     } else if (s->type==2 || s->type==5) {
00070         if (avctx->codec_id == CODEC_ID_PGMYUV)
00071             avctx->pix_fmt = PIX_FMT_YUV420P;
00072         else
00073             avctx->pix_fmt = PIX_FMT_GRAY8;
00074     } else if (s->type==3 || s->type==6) {
00075         avctx->pix_fmt = PIX_FMT_RGB24;
00076     } else if (s->type==7) {
00077         w      = -1;
00078         h      = -1;
00079         maxval = -1;
00080         depth  = -1;
00081         tuple_type[0] = '\0';
00082         for (;;) {
00083             pnm_get(s, buf1, sizeof(buf1));
00084             if (!strcmp(buf1, "WIDTH")) {
00085                 pnm_get(s, buf1, sizeof(buf1));
00086                 w = strtol(buf1, NULL, 10);
00087             } else if (!strcmp(buf1, "HEIGHT")) {
00088                 pnm_get(s, buf1, sizeof(buf1));
00089                 h = strtol(buf1, NULL, 10);
00090             } else if (!strcmp(buf1, "DEPTH")) {
00091                 pnm_get(s, buf1, sizeof(buf1));
00092                 depth = strtol(buf1, NULL, 10);
00093             } else if (!strcmp(buf1, "MAXVAL")) {
00094                 pnm_get(s, buf1, sizeof(buf1));
00095                 maxval = strtol(buf1, NULL, 10);
00096             } else if (!strcmp(buf1, "TUPLETYPE")) {
00097                 pnm_get(s, tuple_type, sizeof(tuple_type));
00098             } else if (!strcmp(buf1, "ENDHDR")) {
00099                 break;
00100             } else {
00101                 return -1;
00102             }
00103         }
00104         /* check that all tags are present */
00105         if (w <= 0 || h <= 0 || maxval <= 0 || depth <= 0 || tuple_type[0] == '\0' || av_image_check_size(w, h, 0, avctx))
00106             return -1;
00107 
00108         avctx->width  = w;
00109         avctx->height = h;
00110         if (depth == 1) {
00111             if (maxval == 1)
00112                 avctx->pix_fmt = PIX_FMT_MONOWHITE;
00113             else
00114                 avctx->pix_fmt = PIX_FMT_GRAY8;
00115         } else if (depth == 3) {
00116             if (maxval < 256) {
00117             avctx->pix_fmt = PIX_FMT_RGB24;
00118             } else {
00119                 av_log(avctx, AV_LOG_ERROR, "16-bit components are only supported for grayscale\n");
00120                 avctx->pix_fmt = PIX_FMT_NONE;
00121                 return -1;
00122             }
00123         } else if (depth == 4) {
00124             avctx->pix_fmt = PIX_FMT_RGB32;
00125         } else {
00126             return -1;
00127         }
00128         return 0;
00129     } else {
00130         return -1;
00131     }
00132     pnm_get(s, buf1, sizeof(buf1));
00133     avctx->width = atoi(buf1);
00134     if (avctx->width <= 0)
00135         return -1;
00136     pnm_get(s, buf1, sizeof(buf1));
00137     avctx->height = atoi(buf1);
00138     if(av_image_check_size(avctx->width, avctx->height, 0, avctx))
00139         return -1;
00140     if (avctx->pix_fmt != PIX_FMT_MONOWHITE) {
00141         pnm_get(s, buf1, sizeof(buf1));
00142         s->maxval = atoi(buf1);
00143         if (s->maxval <= 0) {
00144             av_log(avctx, AV_LOG_ERROR, "Invalid maxval: %d\n", s->maxval);
00145             s->maxval = 255;
00146         }
00147         if (s->maxval >= 256) {
00148             if (avctx->pix_fmt == PIX_FMT_GRAY8) {
00149                 avctx->pix_fmt = PIX_FMT_GRAY16BE;
00150                 if (s->maxval != 65535)
00151                     avctx->pix_fmt = PIX_FMT_GRAY16;
00152             } else if (avctx->pix_fmt == PIX_FMT_RGB24) {
00153                 if (s->maxval > 255)
00154                     avctx->pix_fmt = PIX_FMT_RGB48BE;
00155             } else {
00156                 av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format\n");
00157                 avctx->pix_fmt = PIX_FMT_NONE;
00158                 return -1;
00159             }
00160         }
00161     }else
00162         s->maxval=1;
00163     /* more check if YUV420 */
00164     if (avctx->pix_fmt == PIX_FMT_YUV420P) {
00165         if ((avctx->width & 1) != 0)
00166             return -1;
00167         h = (avctx->height * 2);
00168         if ((h % 3) != 0)
00169             return -1;
00170         h /= 3;
00171         avctx->height = h;
00172     }
00173     return 0;
00174 }
00175 
00176 av_cold int ff_pnm_end(AVCodecContext *avctx)
00177 {
00178     PNMContext *s = avctx->priv_data;
00179 
00180     if (s->picture.data[0])
00181         avctx->release_buffer(avctx, &s->picture);
00182 
00183     return 0;
00184 }
00185 
00186 av_cold int ff_pnm_init(AVCodecContext *avctx)
00187 {
00188     PNMContext *s = avctx->priv_data;
00189 
00190     avcodec_get_frame_defaults((AVFrame*)&s->picture);
00191     avctx->coded_frame = (AVFrame*)&s->picture;
00192 
00193     return 0;
00194 }
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