mirror of
https://github.com/FFmpeg/FFmpeg.git
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117 lines
3.3 KiB
C
117 lines
3.3 KiB
C
/*
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* Microsoft Paint (MSP) demuxer
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* Copyright (c) 2020 Peter Ross (pross@xvid.org)
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Microsoft Paint (MSP) demuxer
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*/
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#include "libavutil/intreadwrite.h"
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#include "libavutil/imgutils.h"
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#include "avformat.h"
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#include "internal.h"
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typedef struct {
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int packet_size;
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} MSPContext;
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static int msp_probe(const AVProbeData *p)
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{
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unsigned int i, sum;
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if (p->buf_size <= 32 || (memcmp(p->buf, "DanM", 4) && memcmp(p->buf, "LinS", 4)))
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return 0;
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sum = 0;
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for (i = 0; i < 24; i += 2)
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sum ^= AV_RL16(p->buf + i);
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return AV_RL16(p->buf + 24) == sum ? AVPROBE_SCORE_MAX : 0;
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}
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static int msp_read_header(AVFormatContext *s)
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{
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MSPContext * cntx = s->priv_data;
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AVIOContext *pb = s->pb;
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AVStream *st;
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st = avformat_new_stream(s, NULL);
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if (!st)
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return AVERROR(ENOMEM);
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st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
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st->codecpar->codec_id = avio_rl32(pb) == MKTAG('D', 'a', 'n', 'M') ? AV_CODEC_ID_RAWVIDEO : AV_CODEC_ID_MSP2;
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st->codecpar->width = avio_rl16(pb);
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st->codecpar->height = avio_rl16(pb);
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st->codecpar->format = AV_PIX_FMT_MONOBLACK;
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st->sample_aspect_ratio.num = avio_rl16(pb);
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st->sample_aspect_ratio.den = avio_rl16(pb);
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avio_skip(pb, 20);
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if (st->codecpar->codec_id == AV_CODEC_ID_RAWVIDEO) {
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cntx->packet_size = av_image_get_buffer_size(st->codecpar->format, st->codecpar->width, st->codecpar->height, 1);
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if (cntx->packet_size < 0)
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return cntx->packet_size;
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} else
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cntx->packet_size = 2 * st->codecpar->height;
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return 0;
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}
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static int msp_read_packet(AVFormatContext *s, AVPacket *pkt)
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{
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AVStream *st = s->streams[0];
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MSPContext *cntx = s->priv_data;
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int ret;
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ret = av_get_packet(s->pb, pkt, cntx->packet_size);
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if (ret < 0)
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return ret;
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if (st->codecpar->codec_id == AV_CODEC_ID_MSP2) {
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unsigned int size, i;
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if (pkt->size != 2 * st->codecpar->height)
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return AVERROR_INVALIDDATA;
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size = 0;
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for (i = 0; i < st->codecpar->height; i++)
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size += AV_RL16(&pkt->data[i * 2]);
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ret = av_append_packet(s->pb, pkt, size);
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if (ret < 0)
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return ret;
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}
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pkt->stream_index = 0;
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pkt->flags |= AV_PKT_FLAG_KEY;
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return 0;
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}
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AVInputFormat ff_msp_demuxer = {
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.name = "msp",
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.long_name = NULL_IF_CONFIG_SMALL("Microsoft Paint (MSP))"),
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.read_probe = msp_probe,
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.read_header = msp_read_header,
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.read_packet = msp_read_packet,
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.flags = AVFMT_NOTIMESTAMPS,
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.priv_data_size = sizeof(MSPContext),
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};
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