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 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/intreadwrite.h"
23 #include "libavutil/imgutils.h"
24 #include "avcodec.h"
25 
26 typedef struct PTXContext {
28 } PTXContext;
29 
30 static av_cold int ptx_init(AVCodecContext *avctx) {
31  PTXContext *s = avctx->priv_data;
32 
34  avctx->coded_frame= &s->picture;
35 
36  return 0;
37 }
38 
39 static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
40  AVPacket *avpkt) {
41  const uint8_t *buf = avpkt->data;
42  const uint8_t *buf_end = avpkt->data + avpkt->size;
43  PTXContext * const s = avctx->priv_data;
44  AVFrame *picture = data;
45  AVFrame * const p = &s->picture;
46  unsigned int offset, w, h, y, stride, bytes_per_pixel;
47  uint8_t *ptr;
48 
49  if (buf_end - buf < 14)
50  return AVERROR_INVALIDDATA;
51  offset = AV_RL16(buf);
52  w = AV_RL16(buf+8);
53  h = AV_RL16(buf+10);
54  bytes_per_pixel = AV_RL16(buf+12) >> 3;
55 
56  if (bytes_per_pixel != 2) {
57  av_log_ask_for_sample(avctx, "Image format is not RGB15.\n");
58  return -1;
59  }
60 
61  avctx->pix_fmt = PIX_FMT_RGB555;
62 
63  if (buf_end - buf < offset)
64  return AVERROR_INVALIDDATA;
65  if (offset != 0x2c)
66  av_log_ask_for_sample(avctx, "offset != 0x2c\n");
67 
68  buf += offset;
69 
70  if (p->data[0])
71  avctx->release_buffer(avctx, p);
72 
73  if (av_image_check_size(w, h, 0, avctx))
74  return -1;
75  if (w != avctx->width || h != avctx->height)
76  avcodec_set_dimensions(avctx, w, h);
77  if (avctx->get_buffer(avctx, p) < 0) {
78  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
79  return -1;
80  }
81 
83 
84  ptr = p->data[0];
85  stride = p->linesize[0];
86 
87  for (y = 0; y < h && buf_end - buf >= w * bytes_per_pixel; y++) {
88 #if HAVE_BIGENDIAN
89  unsigned int x;
90  for (x=0; x<w*bytes_per_pixel; x+=bytes_per_pixel)
91  AV_WN16(ptr+x, AV_RL16(buf+x));
92 #else
93  memcpy(ptr, buf, w*bytes_per_pixel);
94 #endif
95  ptr += stride;
96  buf += w*bytes_per_pixel;
97  }
98 
99  *picture = s->picture;
100  *data_size = sizeof(AVPicture);
101 
102  if (y < h) {
103  av_log(avctx, AV_LOG_WARNING, "incomplete packet\n");
104  return avpkt->size;
105  }
106 
107  return offset + w*h*bytes_per_pixel;
108 }
109 
110 static av_cold int ptx_end(AVCodecContext *avctx) {
111  PTXContext *s = avctx->priv_data;
112 
113  if(s->picture.data[0])
114  avctx->release_buffer(avctx, &s->picture);
115 
116  return 0;
117 }
118 
120  .name = "ptx",
121  .type = AVMEDIA_TYPE_VIDEO,
122  .id = CODEC_ID_PTX,
123  .priv_data_size = sizeof(PTXContext),
124  .init = ptx_init,
125  .close = ptx_end,
127  .capabilities = CODEC_CAP_DR1,
128  .long_name = NULL_IF_CONFIG_SMALL("V.Flash PTX image"),
129 };