libavcodec/ptx.c

   1 /*
   2  * V.Flash PTX (.ptx) image decoder
   3  * Copyright (c) 2007 Ivo van Poorten
   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 "libavutil/intreadwrite.h"
  23 #include "avcodec.h"
  24
  25 typedef struct PTXContext {
  26     AVFrame picture;
  27 } PTXContext;
  28
  29 static av_cold int ptx_init(AVCodecContext *avctx) {
  30     PTXContext *s = avctx->priv_data;
  31
  32     avcodec_get_frame_defaults(&s->picture);
  33     avctx->coded_frame= &s->picture;
  34
  35     return 0;
  36 }
  37
  38 static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
  39                             AVPacket *avpkt) {
  40     const uint8_t *buf = avpkt->data;
  41     PTXContext * const s = avctx->priv_data;
  42     AVFrame *picture = data;
  43     AVFrame * const p = &s->picture;
  44     unsigned int offset, w, h, y, stride, bytes_per_pixel;
  45     uint8_t *ptr;
  46
  47     offset          = AV_RL16(buf);
  48     w               = AV_RL16(buf+8);
  49     h               = AV_RL16(buf+10);
  50     bytes_per_pixel = AV_RL16(buf+12) >> 3;
  51
  52     if (bytes_per_pixel != 2) {
  53         av_log(avctx, AV_LOG_ERROR, "image format is not rgb15, please report on ffmpeg-users mailing list\n");
  54         return -1;
  55     }
  56
  57     avctx->pix_fmt = PIX_FMT_RGB555;
  58
  59     if (offset != 0x2c)
  60         av_log(avctx, AV_LOG_WARNING, "offset != 0x2c, untested due to lack of sample files\n");
  61
  62     buf += offset;
  63
  64     if (p->data[0])
  65         avctx->release_buffer(avctx, p);
  66
  67     if (avcodec_check_dimensions(avctx, w, h))
  68         return -1;
  69     if (w != avctx->width || h != avctx->height)
  70         avcodec_set_dimensions(avctx, w, h);
  71     if (avctx->get_buffer(avctx, p) < 0) {
  72         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  73         return -1;
  74     }
  75
  76     p->pict_type = FF_I_TYPE;
  77
  78     ptr    = p->data[0];
  79     stride = p->linesize[0];
  80
  81     for (y=0; y<h; y++) {
  82 #ifdef WORDS_BIGENDIAN
  83         unsigned int x;
  84         for (x=0; x<w*bytes_per_pixel; x+=bytes_per_pixel)
  85             AV_WN16(ptr+x, AV_RL16(buf+x));
  86 #else
  87         memcpy(ptr, buf, w*bytes_per_pixel);
  88 #endif
  89         ptr += stride;
  90         buf += w*bytes_per_pixel;
  91     }
  92
  93     *picture = s->picture;
  94     *data_size = sizeof(AVPicture);
  95
  96     return offset + w*h*bytes_per_pixel;
  97 }
  98
  99 static av_cold int ptx_end(AVCodecContext *avctx) {
 100     PTXContext *s = avctx->priv_data;
 101
 102     if(s->picture.data[0])
 103         avctx->release_buffer(avctx, &s->picture);
 104
 105     return 0;
 106 }
 107
 108 AVCodec ptx_decoder = {
 109     "ptx",
 110     CODEC_TYPE_VIDEO,
 111     CODEC_ID_PTX,
 112     sizeof(PTXContext),
 113     ptx_init,
 114     NULL,
 115     ptx_end,
 116     ptx_decode_frame,
 117     CODEC_CAP_DR1,
 118     NULL,
 119     .long_name = NULL_IF_CONFIG_SMALL("V.Flash PTX image"),
 120 };