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ptx.c
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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/common.h"
23 #include "libavutil/intreadwrite.h"
24 #include "libavutil/imgutils.h"
25 #include "avcodec.h"
26 #include "internal.h"
27 
28 static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
29  AVPacket *avpkt) {
30  const uint8_t *buf = avpkt->data;
31  const uint8_t *buf_end = avpkt->data + avpkt->size;
32  AVFrame * const p = data;
33  unsigned int offset, w, h, y, stride, bytes_per_pixel;
34  int ret;
35  uint8_t *ptr;
36 
37  if (buf_end - buf < 14)
38  return AVERROR_INVALIDDATA;
39  offset = AV_RL16(buf);
40  w = AV_RL16(buf+8);
41  h = AV_RL16(buf+10);
42  bytes_per_pixel = AV_RL16(buf+12) >> 3;
43 
44  if (bytes_per_pixel != 2) {
45  avpriv_request_sample(avctx, "Image format not RGB15");
46  return AVERROR_PATCHWELCOME;
47  }
48 
50 
51  if (buf_end - buf < offset)
52  return AVERROR_INVALIDDATA;
53  if (offset != 0x2c)
54  avpriv_request_sample(avctx, "offset != 0x2c");
55 
56  buf += offset;
57 
58  if ((ret = av_image_check_size(w, h, 0, avctx)) < 0)
59  return ret;
60  if (w != avctx->width || h != avctx->height)
61  avcodec_set_dimensions(avctx, w, h);
62  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
63  return ret;
64 
66 
67  ptr = p->data[0];
68  stride = p->linesize[0];
69 
70  for (y = 0; y < h && buf_end - buf >= w * bytes_per_pixel; y++) {
71  memcpy(ptr, buf, w*bytes_per_pixel);
72  ptr += stride;
73  buf += w*bytes_per_pixel;
74  }
75 
76  *got_frame = 1;
77 
78  if (y < h) {
79  av_log(avctx, AV_LOG_WARNING, "incomplete packet\n");
80  return avpkt->size;
81  }
82 
83  return offset + w*h*bytes_per_pixel;
84 }
85 
87  .name = "ptx",
88  .type = AVMEDIA_TYPE_VIDEO,
89  .id = AV_CODEC_ID_PTX,
90  .decode = ptx_decode_frame,
91  .capabilities = CODEC_CAP_DR1,
92  .long_name = NULL_IF_CONFIG_SMALL("V.Flash PTX image"),
93 };