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ffmpeg/libavformat/icodec.c

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/*
* Microsoft Windows ICO demuxer
* Copyright (c) 2011 Peter Ross (pross@xvid.org)
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Microsoft Windows ICO demuxer
*/
#include "libavutil/intreadwrite.h"
#include "libavcodec/bytestream.h"
#include "libavcodec/bmp.h"
#include "libavcodec/png.h"
#include "avformat.h"
#include "internal.h"
typedef struct {
int offset;
int size;
int nb_pal;
} IcoImage;
typedef struct {
int current_image;
int nb_images;
IcoImage * images;
} IcoDemuxContext;
static int probe(const AVProbeData *p)
{
unsigned i, frames, checked = 0;
if (p->buf_size < 22 || AV_RL16(p->buf) || AV_RL16(p->buf + 2) != 1)
return 0;
frames = AV_RL16(p->buf + 4);
if (!frames)
return 0;
for (i = 0; i < frames && i * 16 + 22 <= p->buf_size; i++) {
unsigned offset;
if (AV_RL16(p->buf + 10 + i * 16) & ~1)
return FFMIN(i, AVPROBE_SCORE_MAX / 4);
if (p->buf[13 + i * 16])
return FFMIN(i, AVPROBE_SCORE_MAX / 4);
if (AV_RL32(p->buf + 14 + i * 16) < 40)
return FFMIN(i, AVPROBE_SCORE_MAX / 4);
offset = AV_RL32(p->buf + 18 + i * 16);
if (offset < 22)
return FFMIN(i, AVPROBE_SCORE_MAX / 4);
if (offset > p->buf_size - 8)
continue;
if (p->buf[offset] != 40 && AV_RB64(p->buf + offset) != PNGSIG)
return FFMIN(i, AVPROBE_SCORE_MAX / 4);
checked++;
}
if (checked < frames)
return AVPROBE_SCORE_MAX / 4 + FFMIN(checked, 1);
return AVPROBE_SCORE_MAX / 2 + 1;
}
static int read_header(AVFormatContext *s)
{
IcoDemuxContext *ico = s->priv_data;
AVIOContext *pb = s->pb;
int i, codec;
avio_skip(pb, 4);
ico->nb_images = avio_rl16(pb);
if (!ico->nb_images)
return AVERROR_INVALIDDATA;
ico->images = av_malloc_array(ico->nb_images, sizeof(IcoImage));
if (!ico->images)
return AVERROR(ENOMEM);
for (i = 0; i < ico->nb_images; i++) {
AVStream *st;
int tmp;
if (avio_seek(pb, 6 + i * 16, SEEK_SET) < 0)
goto fail;
st = avformat_new_stream(s, NULL);
if (!st) {
av_freep(&ico->images);
return AVERROR(ENOMEM);
}
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->width = avio_r8(pb);
st->codecpar->height = avio_r8(pb);
ico->images[i].nb_pal = avio_r8(pb);
if (ico->images[i].nb_pal == 255)
ico->images[i].nb_pal = 0;
avio_skip(pb, 5);
ico->images[i].size = avio_rl32(pb);
if (ico->images[i].size <= 0) {
av_log(s, AV_LOG_ERROR, "Invalid image size %d\n", ico->images[i].size);
goto fail;
}
ico->images[i].offset = avio_rl32(pb);
if (avio_seek(pb, ico->images[i].offset, SEEK_SET) < 0)
goto fail;
codec = avio_rl32(pb);
switch (codec) {
case MKTAG(0x89, 'P', 'N', 'G'):
st->codecpar->codec_id = AV_CODEC_ID_PNG;
st->codecpar->width = 0;
st->codecpar->height = 0;
break;
case 40:
if (ico->images[i].size < 40) {
goto fail;
}
st->codecpar->codec_id = AV_CODEC_ID_BMP;
tmp = avio_rl32(pb);
if (tmp)
st->codecpar->width = tmp;
tmp = avio_rl32(pb);
if (tmp)
st->codecpar->height = tmp / 2;
break;
default:
avpriv_request_sample(s, "codec %d", codec);
goto fail;
}
}
return 0;
fail:
av_freep(&ico->images);
return AVERROR_INVALIDDATA;
}
static int read_packet(AVFormatContext *s, AVPacket *pkt)
{
IcoDemuxContext *ico = s->priv_data;
IcoImage *image;
AVIOContext *pb = s->pb;
AVStream *st;
int ret;
if (ico->current_image >= ico->nb_images)
return AVERROR_EOF;
st = s->streams[0];
image = &ico->images[ico->current_image];
if ((ret = avio_seek(pb, image->offset, SEEK_SET)) < 0)
return ret;
if (s->streams[ico->current_image]->codecpar->codec_id == AV_CODEC_ID_PNG) {
if ((ret = av_get_packet(pb, pkt, image->size)) < 0)
return ret;
} else {
uint8_t *buf;
if ((ret = av_new_packet(pkt, 14 + image->size)) < 0)
return ret;
buf = pkt->data;
/* add BMP header */
bytestream_put_byte(&buf, 'B');
bytestream_put_byte(&buf, 'M');
bytestream_put_le32(&buf, pkt->size);
bytestream_put_le16(&buf, 0);
bytestream_put_le16(&buf, 0);
bytestream_put_le32(&buf, 0);
if ((ret = avio_read(pb, buf, image->size)) != image->size) {
av_packet_unref(pkt);
return ret < 0 ? ret : AVERROR_INVALIDDATA;
}
st->codecpar->bits_per_coded_sample = AV_RL16(buf + 14);
if (AV_RL32(buf + 32))
image->nb_pal = AV_RL32(buf + 32);
if (st->codecpar->bits_per_coded_sample <= 8 && !image->nb_pal) {
image->nb_pal = 1 << st->codecpar->bits_per_coded_sample;
AV_WL32(buf + 32, image->nb_pal);
}
if (image->nb_pal > INT_MAX / 4 - 14 - 40)
return AVERROR_INVALIDDATA;
AV_WL32(buf - 4, 14 + 40 + image->nb_pal * 4);
AV_WL32(buf + 8, AV_RL32(buf + 8) / 2);
}
pkt->stream_index = ico->current_image++;
pkt->flags |= AV_PKT_FLAG_KEY;
return 0;
}
static int ico_read_close(AVFormatContext * s)
{
IcoDemuxContext *ico = s->priv_data;
av_freep(&ico->images);
return 0;
}
AVInputFormat ff_ico_demuxer = {
.name = "ico",
.long_name = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),
.priv_data_size = sizeof(IcoDemuxContext),
.read_probe = probe,
.read_header = read_header,
.read_packet = read_packet,
.read_close = ico_read_close,
.flags = AVFMT_NOTIMESTAMPS,
};
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