modules/codec/xwd.c

   1 /*****************************************************************************
   2  * xwd.c: X Window system raster image dump pseudo-decoder
   3  *****************************************************************************
   4  * Copyright (C) 2012 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <assert.h>
  26 #include <arpa/inet.h>
  27 #include <X11/XWDFile.h>
  28
  29 #include <vlc_common.h>
  30 #include <vlc_plugin.h>
  31 #include <vlc_codec.h>
  32
  33 static int Open(vlc_object_t *);
  34
  35 vlc_module_begin()
  36     set_description(N_("XWD image decoder"))
  37     set_capability("decoder", 50)
  38     set_category(CAT_INPUT)
  39     set_subcategory(SUBCAT_INPUT_VCODEC)
  40     set_callbacks(Open, NULL)
  41 vlc_module_end()
  42
  43 static picture_t *Decode(decoder_t *, block_t **);
  44
  45 static int Open(vlc_object_t *obj)
  46 {
  47     decoder_t *dec = (decoder_t *)obj;
  48
  49     if (dec->fmt_in.i_codec != VLC_CODEC_XWD)
  50         return VLC_EGENERIC;
  51
  52     dec->pf_decode_video = Decode;
  53     es_format_Copy(&dec->fmt_out, &dec->fmt_in);
  54     dec->fmt_out.i_codec = VLC_CODEC_RGB32;
  55     dec->fmt_out.i_cat = VIDEO_ES;
  56     return VLC_SUCCESS;
  57 }
  58
  59 static picture_t *Decode (decoder_t *dec, block_t **pp)
  60 {
  61     picture_t *pic = NULL;
  62
  63     if (pp == NULL)
  64         return NULL;
  65
  66     block_t *block = *pp;
  67     if (block == NULL)
  68         return NULL;
  69     *pp = NULL;
  70
  71     if (block->i_pts <= VLC_TS_INVALID)
  72         goto drop; /* undated block, should never happen */
  73     if (block->i_buffer < sz_XWDheader)
  74         goto drop;
  75
  76     /* Skip XWD header */
  77     const XWDFileHeader *hdr = (const void *)block->p_buffer;
  78     uint32_t hdrlen = ntohl(hdr->header_size);
  79     if (hdrlen < sz_XWDheader
  80      || ntohl(hdr->file_version) < XWD_FILE_VERSION
  81      || ntohl(hdr->pixmap_format) != 2 /* ZPixmap */)
  82         goto drop;
  83
  84     hdrlen += ntohl(hdr->ncolors) * sz_XWDColor;
  85     if (hdrlen > block->i_buffer)
  86         goto drop;
  87     block->p_buffer += hdrlen;
  88     block->i_buffer -= hdrlen;
  89
  90     /* Parse XWD header */
  91     vlc_fourcc_t chroma = 0;
  92     switch (ntohl(hdr->pixmap_depth))
  93     {
  94         case 8:
  95             if (ntohl(hdr->bits_per_pixel) == 8)
  96                 chroma = VLC_CODEC_RGB8;
  97             break;
  98         case 15:
  99             if (ntohl(hdr->bits_per_pixel) == 16)
 100                 chroma = VLC_CODEC_RGB15;
 101             break;
 102         case 16:
 103             if (ntohl(hdr->bits_per_pixel) == 16)
 104                 chroma = VLC_CODEC_RGB16;
 105             break;
 106         case 24:
 107             switch (ntohl(hdr->bits_per_pixel))
 108             {
 109                 case 32: chroma = VLC_CODEC_RGB32; break;
 110                 case 24: chroma = VLC_CODEC_RGB24; break;
 111             }
 112             break;
 113         case 32:
 114             if (ntohl(hdr->bits_per_pixel) == 32)
 115                 chroma = VLC_CODEC_ARGB;
 116             break;
 117     }
 118     /* TODO: check image endianess, set RGB mask */
 119     if (!chroma)
 120         goto drop;
 121
 122     video_format_Setup(&dec->fmt_out.video, chroma,
 123                        ntohl(hdr->pixmap_width), ntohl(hdr->pixmap_height),
 124                        dec->fmt_in.video.i_sar_num,
 125                        dec->fmt_in.video.i_sar_den);
 126
 127     const size_t copy = dec->fmt_out.video.i_width
 128                         * (dec->fmt_out.video.i_bits_per_pixel / 8);
 129     const uint32_t pitch = ntohl(hdr->bytes_per_line);
 130
 131     /* Build picture */
 132     if (pitch < copy
 133      || (block->i_buffer / pitch) < dec->fmt_out.video.i_height)
 134         goto drop;
 135
 136     pic = decoder_NewPicture(dec);
 137     if (pic == NULL)
 138         goto drop;
 139
 140     const uint8_t *in = block->p_buffer;
 141     uint8_t *out = pic->p->p_pixels;
 142     for (unsigned i = 0; i < dec->fmt_out.video.i_height; i++)
 143     {
 144         memcpy(out, in, copy);
 145         in += pitch;
 146         out += pic->p->i_pitch;
 147     }
 148     pic->date = block->i_pts;
 149     pic->b_progressive = true;
 150
 151 drop:
 152     block_Release(block);
 153     return pic;
 154 }