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/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 {
30 } PTXContext;
31 
32 static av_cold int ptx_init(AVCodecContext *avctx) {
33  PTXContext *s = avctx->priv_data;
34 
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  uint8_t *ptr;
50 
51  if (buf_end - buf < 14)
52  return AVERROR_INVALIDDATA;
53  offset = AV_RL16(buf);
54  w = AV_RL16(buf+8);
55  h = AV_RL16(buf+10);
56  bytes_per_pixel = AV_RL16(buf+12) >> 3;
57 
58  if (bytes_per_pixel != 2) {
59  av_log_ask_for_sample(avctx, "Image format is not RGB15.\n");
60  return AVERROR_PATCHWELCOME;
61  }
62 
63  avctx->pix_fmt = AV_PIX_FMT_RGB555;
64 
65  if (buf_end - buf < offset)
66  return AVERROR_INVALIDDATA;
67  if (offset != 0x2c)
68  av_log_ask_for_sample(avctx, "offset != 0x2c\n");
69 
70  buf += offset;
71 
72  if (p->data[0])
73  avctx->release_buffer(avctx, p);
74 
75  if (av_image_check_size(w, h, 0, avctx))
76  return -1;
77  if (w != avctx->width || h != avctx->height)
78  avcodec_set_dimensions(avctx, w, h);
79  if (ff_get_buffer(avctx, p) < 0) {
80  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
81  return -1;
82  }
83 
85 
86  ptr = p->data[0];
87  stride = p->linesize[0];
88 
89  for (y = 0; y < h && buf_end - buf >= w * bytes_per_pixel; y++) {
90 #if HAVE_BIGENDIAN
91  unsigned int x;
92  for (x=0; x<w*bytes_per_pixel; x+=bytes_per_pixel)
93  AV_WN16(ptr+x, AV_RL16(buf+x));
94 #else
95  memcpy(ptr, buf, w*bytes_per_pixel);
96 #endif
97  ptr += stride;
98  buf += w*bytes_per_pixel;
99  }
100 
101  *picture = s->picture;
102  *got_frame = 1;
103 
104  if (y < h) {
105  av_log(avctx, AV_LOG_WARNING, "incomplete packet\n");
106  return avpkt->size;
107  }
108 
109  return offset + w*h*bytes_per_pixel;
110 }
111 
112 static av_cold int ptx_end(AVCodecContext *avctx) {
113  PTXContext *s = avctx->priv_data;
114 
115  if(s->picture.data[0])
116  avctx->release_buffer(avctx, &s->picture);
117 
118  return 0;
119 }
120 
122  .name = "ptx",
123  .type = AVMEDIA_TYPE_VIDEO,
124  .id = AV_CODEC_ID_PTX,
125  .priv_data_size = sizeof(PTXContext),
126  .init = ptx_init,
127  .close = ptx_end,
129  .capabilities = CODEC_CAP_DR1,
130  .long_name = NULL_IF_CONFIG_SMALL("V.Flash PTX image"),
131 };