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