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