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 #ifdef HAVE_ARPA_INET_H
  27 #include <arpa/inet.h>
  28 #endif
  29 #include <X11/XWDFile.h>
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33 #include <vlc_codec.h>
  34
  35 static int Open(vlc_object_t *);
  36
  37 vlc_module_begin()
  38     set_description(N_("XWD image decoder"))
  39     set_capability("video decoder", 50)
  40     set_category(CAT_INPUT)
  41     set_subcategory(SUBCAT_INPUT_VCODEC)
  42     set_callbacks(Open, NULL)
  43 vlc_module_end()
  44
  45 static int Decode(decoder_t *, block_t *);
  46
  47 static int Open(vlc_object_t *obj)
  48 {
  49     decoder_t *dec = (decoder_t *)obj;
  50
  51     if (dec->fmt_in.i_codec != VLC_CODEC_XWD)
  52         return VLC_EGENERIC;
  53
  54     dec->pf_decode = Decode;
  55     es_format_Copy(&dec->fmt_out, &dec->fmt_in);
  56     dec->fmt_out.i_codec = VLC_CODEC_RGB32;
  57     return VLC_SUCCESS;
  58 }
  59
  60 static int Decode (decoder_t *dec, block_t *block)
  61 {
  62     picture_t *pic = NULL;
  63
  64     if (block == NULL) /* No Drain */
  65         return VLCDEC_SUCCESS;
  66
  67     if (block->i_pts == VLC_TICK_INVALID)
  68         goto drop; /* undated block, should never happen */
  69     if (block->i_buffer < sz_XWDheader)
  70         goto drop;
  71
  72     /* Skip XWD header */
  73     const XWDFileHeader *hdr = (const void *)block->p_buffer;
  74     uint32_t hdrlen = ntohl(hdr->header_size);
  75     if (hdrlen < sz_XWDheader
  76      || ntohl(hdr->file_version) < XWD_FILE_VERSION
  77      || ntohl(hdr->pixmap_format) != 2 /* ZPixmap */)
  78         goto drop;
  79
  80     hdrlen += ntohl(hdr->ncolors) * sz_XWDColor;
  81     if (hdrlen > block->i_buffer)
  82         goto drop;
  83     block->p_buffer += hdrlen;
  84     block->i_buffer -= hdrlen;
  85
  86     /* Parse XWD header */
  87     vlc_fourcc_t chroma = 0;
  88     switch (ntohl(hdr->pixmap_depth))
  89     {
  90         case 8:
  91             if (ntohl(hdr->bits_per_pixel) == 8)
  92                 chroma = VLC_CODEC_RGB8;
  93             break;
  94         case 15:
  95             if (ntohl(hdr->bits_per_pixel) == 16)
  96                 chroma = VLC_CODEC_RGB15;
  97             break;
  98         case 16:
  99             if (ntohl(hdr->bits_per_pixel) == 16)
 100                 chroma = VLC_CODEC_RGB16;
 101             break;
 102         case 24:
 103             switch (ntohl(hdr->bits_per_pixel))
 104             {
 105                 case 32: chroma = VLC_CODEC_RGB32; break;
 106                 case 24: chroma = VLC_CODEC_RGB24; break;
 107             }
 108             break;
 109         case 32:
 110             if (ntohl(hdr->bits_per_pixel) == 32)
 111                 chroma = VLC_CODEC_ARGB;
 112             break;
 113     }
 114     /* TODO: check image endianess, set RGB mask */
 115     if (!chroma)
 116         goto drop;
 117
 118     video_format_Setup(&dec->fmt_out.video, chroma,
 119                        ntohl(hdr->pixmap_width), ntohl(hdr->pixmap_height),
 120                        ntohl(hdr->pixmap_width), ntohl(hdr->pixmap_height),
 121                        dec->fmt_in.video.i_sar_num,
 122                        dec->fmt_in.video.i_sar_den);
 123
 124     const size_t copy = dec->fmt_out.video.i_width
 125                         * (dec->fmt_out.video.i_bits_per_pixel / 8);
 126     const uint32_t pitch = ntohl(hdr->bytes_per_line);
 127
 128     /* Build picture */
 129     if (pitch < copy
 130      || (block->i_buffer / pitch) < dec->fmt_out.video.i_height)
 131         goto drop;
 132
 133     if (decoder_UpdateVideoFormat(dec))
 134         goto drop;
 135     pic = decoder_NewPicture(dec);
 136     if (pic == NULL)
 137         goto drop;
 138
 139     const uint8_t *in = block->p_buffer;
 140     uint8_t *out = pic->p->p_pixels;
 141     for (unsigned i = 0; i < dec->fmt_out.video.i_height; i++)
 142     {
 143         memcpy(out, in, copy);
 144         in += pitch;
 145         out += pic->p->i_pitch;
 146     }
 147     pic->date = block->i_pts;
 148     pic->b_progressive = true;
 149
 150 drop:
 151     block_Release(block);
 152     decoder_QueueVideo(dec, pic);
 153     return VLCDEC_SUCCESS;
 154 }