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 Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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/common.h"
  23 #include "libavutil/intreadwrite.h"
  24 #include "libavutil/imgutils.h"
  25 #include "avcodec.h"
  26 #include "internal.h"
  27
  28 typedef struct PTXContext {
  29     AVFrame picture;
  30 } PTXContext;
  31
  32 static av_cold int ptx_init(AVCodecContext *avctx) {
  33     PTXContext *s = avctx->priv_data;
  34
  35     avcodec_get_frame_defaults(&s->picture);
  36     avctx->coded_frame= &s->picture;
  37
  38     return 0;
  39 }
  40
  41 static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
  42                             AVPacket *avpkt) {
  43     const uint8_t *buf = avpkt->data;
  44     const uint8_t *buf_end = avpkt->data + avpkt->size;
  45     PTXContext * const s = avctx->priv_data;
  46     AVFrame *picture = data;
  47     AVFrame * const p = &s->picture;
  48     unsigned int offset, w, h, y, stride, bytes_per_pixel;
  49     int ret;
  50     uint8_t *ptr;
  51
  52     if (buf_end - buf < 14)
  53         return AVERROR_INVALIDDATA;
  54     offset          = AV_RL16(buf);
  55     w               = AV_RL16(buf+8);
  56     h               = AV_RL16(buf+10);
  57     bytes_per_pixel = AV_RL16(buf+12) >> 3;
  58
  59     if (bytes_per_pixel != 2) {
  60         av_log_ask_for_sample(avctx, "Image format is not RGB15.\n");
  61         return AVERROR_PATCHWELCOME;
  62     }
  63
  64     avctx->pix_fmt = AV_PIX_FMT_RGB555;
  65
  66     if (buf_end - buf < offset)
  67         return AVERROR_INVALIDDATA;
  68     if (offset != 0x2c)
  69         av_log_ask_for_sample(avctx, "offset != 0x2c\n");
  70
  71     buf += offset;
  72
  73     if (p->data[0])
  74         avctx->release_buffer(avctx, p);
  75
  76     if ((ret = av_image_check_size(w, h, 0, avctx)) < 0)
  77         return ret;
  78     if (w != avctx->width || h != avctx->height)
  79         avcodec_set_dimensions(avctx, w, h);
  80     if ((ret = ff_get_buffer(avctx, p)) < 0) {
  81         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  82         return ret;
  83     }
  84
  85     p->pict_type = AV_PICTURE_TYPE_I;
  86
  87     ptr    = p->data[0];
  88     stride = p->linesize[0];
  89
  90     for (y = 0; y < h && buf_end - buf >= w * bytes_per_pixel; y++) {
  91 #if HAVE_BIGENDIAN
  92         unsigned int x;
  93         for (x=0; x<w*bytes_per_pixel; x+=bytes_per_pixel)
  94             AV_WN16(ptr+x, AV_RL16(buf+x));
  95 #else
  96         memcpy(ptr, buf, w*bytes_per_pixel);
  97 #endif
  98         ptr += stride;
  99         buf += w*bytes_per_pixel;
 100     }
 101
 102     *picture = s->picture;
 103     *got_frame = 1;
 104
 105     if (y < h) {
 106         av_log(avctx, AV_LOG_WARNING, "incomplete packet\n");
 107         return avpkt->size;
 108     }
 109
 110     return offset + w*h*bytes_per_pixel;
 111 }
 112
 113 static av_cold int ptx_end(AVCodecContext *avctx) {
 114     PTXContext *s = avctx->priv_data;
 115
 116     if(s->picture.data[0])
 117         avctx->release_buffer(avctx, &s->picture);
 118
 119     return 0;
 120 }
 121
 122 AVCodec ff_ptx_decoder = {
 123     .name           = "ptx",
 124     .type           = AVMEDIA_TYPE_VIDEO,
 125     .id             = AV_CODEC_ID_PTX,
 126     .priv_data_size = sizeof(PTXContext),
 127     .init           = ptx_init,
 128     .close          = ptx_end,
 129     .decode         = ptx_decode_frame,
 130     .capabilities   = CODEC_CAP_DR1,
 131     .long_name      = NULL_IF_CONFIG_SMALL("V.Flash PTX image"),
 132 };