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