libavformat/icodec.c
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00001 /*
00002  * Microsoft Windows ICO demuxer
00003  * Copyright (c) 2011 Peter Ross (pross@xvid.org)
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "libavutil/intreadwrite.h"
00028 #include "libavcodec/bytestream.h"
00029 #include "libavcodec/bmp.h"
00030 #include "avformat.h"
00031 #include "internal.h"
00032 
00033 typedef struct {
00034     int offset;
00035     int size;
00036     int nb_pal;
00037 } IcoImage;
00038 
00039 typedef struct {
00040     int current_image;
00041     int nb_images;
00042     IcoImage * images;
00043 } IcoDemuxContext;
00044 
00045 static int probe(AVProbeData *p)
00046 {
00047     if (AV_RL16(p->buf) == 0 && AV_RL16(p->buf + 2) == 1 && AV_RL16(p->buf + 4))
00048         return AVPROBE_SCORE_MAX / 3;
00049     return 0;
00050 }
00051 
00052 static int read_header(AVFormatContext *s, AVFormatParameters *ap)
00053 {
00054     IcoDemuxContext *ico = s->priv_data;
00055     AVIOContext *pb = s->pb;
00056     int i;
00057 
00058     avio_skip(pb, 4);
00059     ico->nb_images = avio_rl16(pb);
00060 
00061     ico->images = av_malloc(ico->nb_images * sizeof(IcoImage));
00062     if (!ico->images)
00063         return AVERROR(ENOMEM);
00064 
00065     for (i = 0; i < ico->nb_images; i++) {
00066         AVStream *st;
00067         int tmp;
00068 
00069         if (avio_seek(pb, 6 + i * 16, SEEK_SET) < 0)
00070             break;
00071 
00072         st = avformat_new_stream(s, NULL);
00073         if (!st)
00074             return AVERROR(ENOMEM);
00075 
00076         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00077         st->codec->width      = avio_r8(pb);
00078         st->codec->height     = avio_r8(pb);
00079         ico->images[i].nb_pal = avio_r8(pb);
00080         if (ico->images[i].nb_pal == 255)
00081             ico->images[i].nb_pal = 0;
00082 
00083         avio_skip(pb, 5);
00084 
00085         ico->images[i].size   = avio_rl32(pb);
00086         ico->images[i].offset = avio_rl32(pb);
00087 
00088         if (avio_seek(pb, ico->images[i].offset, SEEK_SET) < 0)
00089             break;
00090 
00091         switch(avio_rl32(pb)) {
00092         case MKTAG(0x89, 'P', 'N', 'G'):
00093             st->codec->codec_id = CODEC_ID_PNG;
00094             st->codec->width    = 0;
00095             st->codec->height   = 0;
00096             break;
00097         case 40:
00098             if (ico->images[i].size < 40)
00099                 return AVERROR_INVALIDDATA;
00100             st->codec->codec_id = CODEC_ID_BMP;
00101             tmp = avio_rl32(pb);
00102             if (tmp)
00103                 st->codec->width = tmp;
00104             tmp = avio_rl32(pb);
00105             if (tmp)
00106                 st->codec->height = tmp / 2;
00107             break;
00108         default:
00109             av_log_ask_for_sample(s, "unsupported codec\n");
00110             return AVERROR_INVALIDDATA;
00111         }
00112     }
00113 
00114     return 0;
00115 }
00116 
00117 static int read_packet(AVFormatContext *s, AVPacket *pkt)
00118 {
00119     IcoDemuxContext *ico = s->priv_data;
00120     IcoImage *image;
00121     AVIOContext *pb = s->pb;
00122     AVStream *st = s->streams[0];
00123     int ret;
00124 
00125     if (ico->current_image >= ico->nb_images)
00126         return AVERROR(EIO);
00127 
00128     image = &ico->images[ico->current_image];
00129 
00130     if ((ret = avio_seek(pb, image->offset, SEEK_SET)) < 0)
00131         return ret;
00132 
00133     if (s->streams[ico->current_image]->codec->codec_id == CODEC_ID_PNG) {
00134         if ((ret = av_get_packet(pb, pkt, image->size)) < 0)
00135             return ret;
00136     } else {
00137         uint8_t *buf;
00138         if ((ret = av_new_packet(pkt, 14 + image->size)) < 0)
00139             return ret;
00140         buf = pkt->data;
00141 
00142         /* add BMP header */
00143         bytestream_put_byte(&buf, 'B');
00144         bytestream_put_byte(&buf, 'M');
00145         bytestream_put_le32(&buf, pkt->size);
00146         bytestream_put_le16(&buf, 0);
00147         bytestream_put_le16(&buf, 0);
00148         bytestream_put_le32(&buf, 0);
00149 
00150         if ((ret = avio_read(pb, buf, image->size)) < 0)
00151             return ret;
00152 
00153         st->codec->bits_per_coded_sample = AV_RL16(buf + 14);
00154 
00155         if (AV_RL32(buf + 32))
00156             image->nb_pal = AV_RL32(buf + 32);
00157 
00158         if (st->codec->bits_per_coded_sample <= 8 && !image->nb_pal) {
00159             image->nb_pal = 1 << st->codec->bits_per_coded_sample;
00160             AV_WL32(buf + 32, image->nb_pal);
00161         }
00162 
00163         AV_WL32(buf - 4, 14 + 40 + image->nb_pal * 4);
00164         AV_WL32(buf + 8, AV_RL32(buf + 8) / 2);
00165     }
00166 
00167     pkt->stream_index = ico->current_image++;
00168     pkt->flags |= AV_PKT_FLAG_KEY;
00169 
00170     return 0;
00171 }
00172 
00173 AVInputFormat ff_ico_demuxer = {
00174     .name           = "ico",
00175     .long_name      = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
00176     .priv_data_size = sizeof(IcoDemuxContext),
00177     .read_probe     = probe,
00178     .read_header    = read_header,
00179     .read_packet    = read_packet,
00180     .flags          = AVFMT_NOTIMESTAMPS,
00181 };