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icodec.c
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1 /*
2  * Microsoft Windows ICO demuxer
3  * Copyright (c) 2011 Peter Ross (pross@xvid.org)
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 /**
23  * @file
24  * Microsoft Windows ICO demuxer
25  */
26 
27 #include "libavutil/intreadwrite.h"
28 #include "libavcodec/bytestream.h"
29 #include "libavcodec/bmp.h"
30 #include "avformat.h"
31 #include "internal.h"
32 
33 typedef struct {
34  int offset;
35  int size;
36  int nb_pal;
37 } IcoImage;
38 
39 typedef struct {
41  int nb_images;
44 
45 static int probe(AVProbeData *p)
46 {
47  if (AV_RL16(p->buf) == 0 && AV_RL16(p->buf + 2) == 1 && AV_RL16(p->buf + 4))
48  return AVPROBE_SCORE_MAX / 4;
49  return 0;
50 }
51 
53 {
54  IcoDemuxContext *ico = s->priv_data;
55  AVIOContext *pb = s->pb;
56  int i, codec;
57 
58  avio_skip(pb, 4);
59  ico->nb_images = avio_rl16(pb);
60 
61  ico->images = av_malloc(ico->nb_images * sizeof(IcoImage));
62  if (!ico->images)
63  return AVERROR(ENOMEM);
64 
65  for (i = 0; i < ico->nb_images; i++) {
66  AVStream *st;
67  int tmp;
68 
69  if (avio_seek(pb, 6 + i * 16, SEEK_SET) < 0)
70  break;
71 
72  st = avformat_new_stream(s, NULL);
73  if (!st)
74  return AVERROR(ENOMEM);
75 
77  st->codec->width = avio_r8(pb);
78  st->codec->height = avio_r8(pb);
79  ico->images[i].nb_pal = avio_r8(pb);
80  if (ico->images[i].nb_pal == 255)
81  ico->images[i].nb_pal = 0;
82 
83  avio_skip(pb, 5);
84 
85  ico->images[i].size = avio_rl32(pb);
86  ico->images[i].offset = avio_rl32(pb);
87 
88  if (avio_seek(pb, ico->images[i].offset, SEEK_SET) < 0)
89  break;
90 
91  codec = avio_rl32(pb);
92  switch (codec) {
93  case MKTAG(0x89, 'P', 'N', 'G'):
95  st->codec->width = 0;
96  st->codec->height = 0;
97  break;
98  case 40:
99  if (ico->images[i].size < 40)
100  return AVERROR_INVALIDDATA;
102  tmp = avio_rl32(pb);
103  if (tmp)
104  st->codec->width = tmp;
105  tmp = avio_rl32(pb);
106  if (tmp)
107  st->codec->height = tmp / 2;
108  break;
109  default:
110  avpriv_request_sample(s, "codec %d", codec);
111  return AVERROR_INVALIDDATA;
112  }
113  }
114 
115  return 0;
116 }
117 
119 {
120  IcoDemuxContext *ico = s->priv_data;
121  IcoImage *image;
122  AVIOContext *pb = s->pb;
123  AVStream *st = s->streams[0];
124  int ret;
125 
126  if (ico->current_image >= ico->nb_images)
127  return AVERROR(EIO);
128 
129  image = &ico->images[ico->current_image];
130 
131  if ((ret = avio_seek(pb, image->offset, SEEK_SET)) < 0)
132  return ret;
133 
134  if (s->streams[ico->current_image]->codec->codec_id == AV_CODEC_ID_PNG) {
135  if ((ret = av_get_packet(pb, pkt, image->size)) < 0)
136  return ret;
137  } else {
138  uint8_t *buf;
139  if ((ret = av_new_packet(pkt, 14 + image->size)) < 0)
140  return ret;
141  buf = pkt->data;
142 
143  /* add BMP header */
144  bytestream_put_byte(&buf, 'B');
145  bytestream_put_byte(&buf, 'M');
146  bytestream_put_le32(&buf, pkt->size);
147  bytestream_put_le16(&buf, 0);
148  bytestream_put_le16(&buf, 0);
149  bytestream_put_le32(&buf, 0);
150 
151  if ((ret = avio_read(pb, buf, image->size)) < 0)
152  return ret;
153 
154  st->codec->bits_per_coded_sample = AV_RL16(buf + 14);
155 
156  if (AV_RL32(buf + 32))
157  image->nb_pal = AV_RL32(buf + 32);
158 
159  if (st->codec->bits_per_coded_sample <= 8 && !image->nb_pal) {
160  image->nb_pal = 1 << st->codec->bits_per_coded_sample;
161  AV_WL32(buf + 32, image->nb_pal);
162  }
163 
164  AV_WL32(buf - 4, 14 + 40 + image->nb_pal * 4);
165  AV_WL32(buf + 8, AV_RL32(buf + 8) / 2);
166  }
167 
168  pkt->stream_index = ico->current_image++;
169  pkt->flags |= AV_PKT_FLAG_KEY;
170 
171  return 0;
172 }
173 
175  .name = "ico",
176  .long_name = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
177  .priv_data_size = sizeof(IcoDemuxContext),
178  .read_probe = probe,
182 };