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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 "libavcodec/png.h"
31 #include "avformat.h"
32 #include "internal.h"
33 
34 typedef struct {
35     int offset;
36     int size;
37     int nb_pal;
38 } IcoImage;
39 
40 typedef struct {
41     int current_image;
42     int nb_images;
43     IcoImage * images;
44 } IcoDemuxContext;
45 
probe(const AVProbeData * p)46 static int probe(const AVProbeData *p)
47 {
48     unsigned i, frames, checked = 0;
49 
50     if (p->buf_size < 22 || AV_RL16(p->buf) || AV_RL16(p->buf + 2) != 1)
51         return 0;
52     frames = AV_RL16(p->buf + 4);
53     if (!frames)
54         return 0;
55     for (i = 0; i < frames && i * 16 + 22 <= p->buf_size; i++) {
56         unsigned offset;
57         if (AV_RL16(p->buf + 10 + i * 16) & ~1)
58             return FFMIN(i, AVPROBE_SCORE_MAX / 4);
59         if (p->buf[13 + i * 16])
60             return FFMIN(i, AVPROBE_SCORE_MAX / 4);
61         if (AV_RL32(p->buf + 14 + i * 16) < 40)
62             return FFMIN(i, AVPROBE_SCORE_MAX / 4);
63         offset = AV_RL32(p->buf + 18 + i * 16);
64         if (offset < 22)
65             return FFMIN(i, AVPROBE_SCORE_MAX / 4);
66         if (offset > p->buf_size - 8)
67             continue;
68         if (p->buf[offset] != 40 && AV_RB64(p->buf + offset) != PNGSIG)
69             return FFMIN(i, AVPROBE_SCORE_MAX / 4);
70         checked++;
71     }
72 
73     if (checked < frames)
74         return AVPROBE_SCORE_MAX / 4 + FFMIN(checked, 1);
75     return AVPROBE_SCORE_MAX / 2 + 1;
76 }
77 
read_header(AVFormatContext * s)78 static int read_header(AVFormatContext *s)
79 {
80     IcoDemuxContext *ico = s->priv_data;
81     AVIOContext *pb = s->pb;
82     int i, codec;
83 
84     avio_skip(pb, 4);
85     ico->nb_images = avio_rl16(pb);
86 
87     if (!ico->nb_images)
88         return AVERROR_INVALIDDATA;
89 
90     ico->images = av_malloc_array(ico->nb_images, sizeof(IcoImage));
91     if (!ico->images)
92         return AVERROR(ENOMEM);
93 
94     for (i = 0; i < ico->nb_images; i++) {
95         AVStream *st;
96         int tmp;
97 
98         if (avio_seek(pb, 6 + i * 16, SEEK_SET) < 0)
99             goto fail;
100 
101         st = avformat_new_stream(s, NULL);
102         if (!st) {
103             av_freep(&ico->images);
104             return AVERROR(ENOMEM);
105         }
106 
107         st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
108         st->codecpar->width      = avio_r8(pb);
109         st->codecpar->height     = avio_r8(pb);
110         ico->images[i].nb_pal = avio_r8(pb);
111         if (ico->images[i].nb_pal == 255)
112             ico->images[i].nb_pal = 0;
113 
114         avio_skip(pb, 5);
115 
116         ico->images[i].size   = avio_rl32(pb);
117         if (ico->images[i].size <= 0) {
118             av_log(s, AV_LOG_ERROR, "Invalid image size %d\n", ico->images[i].size);
119             goto fail;
120         }
121         ico->images[i].offset = avio_rl32(pb);
122 
123         if (avio_seek(pb, ico->images[i].offset, SEEK_SET) < 0)
124             goto fail;
125 
126         codec = avio_rl32(pb);
127         switch (codec) {
128         case MKTAG(0x89, 'P', 'N', 'G'):
129             st->codecpar->codec_id = AV_CODEC_ID_PNG;
130             st->codecpar->width    = 0;
131             st->codecpar->height   = 0;
132             break;
133         case 40:
134             if (ico->images[i].size < 40) {
135                 goto fail;
136             }
137             st->codecpar->codec_id = AV_CODEC_ID_BMP;
138             tmp = avio_rl32(pb);
139             if (tmp)
140                 st->codecpar->width = tmp;
141             tmp = avio_rl32(pb);
142             if (tmp)
143                 st->codecpar->height = tmp / 2;
144             break;
145         default:
146             avpriv_request_sample(s, "codec %d", codec);
147             goto fail;
148         }
149     }
150 
151     return 0;
152 fail:
153     av_freep(&ico->images);
154     return AVERROR_INVALIDDATA;
155 }
156 
read_packet(AVFormatContext * s,AVPacket * pkt)157 static int read_packet(AVFormatContext *s, AVPacket *pkt)
158 {
159     IcoDemuxContext *ico = s->priv_data;
160     IcoImage *image;
161     AVIOContext *pb = s->pb;
162     AVStream *st;
163     int ret;
164 
165     if (ico->current_image >= ico->nb_images)
166         return AVERROR_EOF;
167 
168     st = s->streams[0];
169 
170     image = &ico->images[ico->current_image];
171 
172     if ((ret = avio_seek(pb, image->offset, SEEK_SET)) < 0)
173         return ret;
174 
175     if (s->streams[ico->current_image]->codecpar->codec_id == AV_CODEC_ID_PNG) {
176         if ((ret = av_get_packet(pb, pkt, image->size)) < 0)
177             return ret;
178     } else {
179         uint8_t *buf;
180         if ((ret = av_new_packet(pkt, 14 + image->size)) < 0)
181             return ret;
182         buf = pkt->data;
183 
184         /* add BMP header */
185         bytestream_put_byte(&buf, 'B');
186         bytestream_put_byte(&buf, 'M');
187         bytestream_put_le32(&buf, pkt->size);
188         bytestream_put_le16(&buf, 0);
189         bytestream_put_le16(&buf, 0);
190         bytestream_put_le32(&buf, 0);
191 
192         if ((ret = avio_read(pb, buf, image->size)) != image->size) {
193             return ret < 0 ? ret : AVERROR_INVALIDDATA;
194         }
195 
196         st->codecpar->bits_per_coded_sample = AV_RL16(buf + 14);
197 
198         if (AV_RL32(buf + 32))
199             image->nb_pal = AV_RL32(buf + 32);
200 
201         if (st->codecpar->bits_per_coded_sample <= 8 && !image->nb_pal) {
202             image->nb_pal = 1 << st->codecpar->bits_per_coded_sample;
203             AV_WL32(buf + 32, image->nb_pal);
204         }
205 
206         AV_WL32(buf - 4, 14 + 40 + image->nb_pal * 4);
207         AV_WL32(buf + 8, AV_RL32(buf + 8) / 2);
208     }
209 
210     pkt->stream_index = ico->current_image++;
211     pkt->flags |= AV_PKT_FLAG_KEY;
212 
213     return 0;
214 }
215 
ico_read_close(AVFormatContext * s)216 static int ico_read_close(AVFormatContext * s)
217 {
218     IcoDemuxContext *ico = s->priv_data;
219     av_freep(&ico->images);
220     return 0;
221 }
222 
223 AVInputFormat ff_ico_demuxer = {
224     .name           = "ico",
225     .long_name      = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
226     .priv_data_size = sizeof(IcoDemuxContext),
227     .read_probe     = probe,
228     .read_header    = read_header,
229     .read_packet    = read_packet,
230     .read_close     = ico_read_close,
231     .flags          = AVFMT_NOTIMESTAMPS,
232 };
233