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 {
40     int current_image;
41     int nb_images;
42     IcoImage * images;
43 } IcoDemuxContext;
44 
probe(AVProbeData * p)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 
read_header(AVFormatContext * s)52 static int read_header(AVFormatContext *s)
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_array(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 
76         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
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'):
94             st->codec->codec_id = AV_CODEC_ID_PNG;
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;
101             st->codec->codec_id = AV_CODEC_ID_BMP;
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 
read_packet(AVFormatContext * s,AVPacket * pkt)118 static int read_packet(AVFormatContext *s, AVPacket *pkt)
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 
174 AVInputFormat ff_ico_demuxer = {
175 	.name           = "ico",
176     .long_name      = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
177     .priv_data_size = sizeof(IcoDemuxContext),
178     .read_probe     = probe,
179     .read_header    = read_header,
180     .read_packet    = read_packet,
181     .flags          = AVFMT_NOTIMESTAMPS,
182 };
183