| /* |
| * Microsoft Paint (MSP) demuxer |
| * Copyright (c) 2020 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 Paint (MSP) demuxer |
| */ |
| |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/imgutils.h" |
| #include "avformat.h" |
| #include "internal.h" |
| |
| typedef struct { |
| int packet_size; |
| } MSPContext; |
| |
| static int msp_probe(const AVProbeData *p) |
| { |
| unsigned int i, sum; |
| |
| if (p->buf_size <= 32 || (memcmp(p->buf, "DanM", 4) && memcmp(p->buf, "LinS", 4))) |
| return 0; |
| |
| sum = 0; |
| for (i = 0; i < 24; i += 2) |
| sum ^= AV_RL16(p->buf + i); |
| |
| return AV_RL16(p->buf + 24) == sum ? AVPROBE_SCORE_MAX : 0; |
| } |
| |
| static int msp_read_header(AVFormatContext *s) |
| { |
| MSPContext * cntx = s->priv_data; |
| AVIOContext *pb = s->pb; |
| AVStream *st; |
| |
| st = avformat_new_stream(s, NULL); |
| if (!st) |
| return AVERROR(ENOMEM); |
| |
| st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
| st->codecpar->codec_id = avio_rl32(pb) == MKTAG('D', 'a', 'n', 'M') ? AV_CODEC_ID_RAWVIDEO : AV_CODEC_ID_MSP2; |
| |
| st->codecpar->width = avio_rl16(pb); |
| st->codecpar->height = avio_rl16(pb); |
| st->codecpar->format = AV_PIX_FMT_MONOBLACK; |
| |
| st->sample_aspect_ratio.num = avio_rl16(pb); |
| st->sample_aspect_ratio.den = avio_rl16(pb); |
| avio_skip(pb, 20); |
| |
| if (st->codecpar->codec_id == AV_CODEC_ID_RAWVIDEO) { |
| cntx->packet_size = av_image_get_buffer_size(st->codecpar->format, st->codecpar->width, st->codecpar->height, 1); |
| if (cntx->packet_size < 0) |
| return cntx->packet_size; |
| } else |
| cntx->packet_size = 2 * st->codecpar->height; |
| |
| return 0; |
| } |
| |
| static int msp_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| AVStream *st = s->streams[0]; |
| MSPContext *cntx = s->priv_data; |
| int ret; |
| |
| ret = av_get_packet(s->pb, pkt, cntx->packet_size); |
| if (ret < 0) |
| return ret; |
| |
| if (st->codecpar->codec_id == AV_CODEC_ID_MSP2) { |
| unsigned int size, i; |
| if (pkt->size != 2 * st->codecpar->height) |
| return AVERROR_INVALIDDATA; |
| size = 0; |
| for (i = 0; i < st->codecpar->height; i++) |
| size += AV_RL16(&pkt->data[i * 2]); |
| ret = av_append_packet(s->pb, pkt, size); |
| if (ret < 0) |
| return ret; |
| } |
| |
| pkt->stream_index = 0; |
| pkt->flags |= AV_PKT_FLAG_KEY; |
| return 0; |
| } |
| |
| AVInputFormat ff_msp_demuxer = { |
| .name = "msp", |
| .long_name = NULL_IF_CONFIG_SMALL("Microsoft Paint (MSP))"), |
| .read_probe = msp_probe, |
| .read_header = msp_read_header, |
| .read_packet = msp_read_packet, |
| .flags = AVFMT_NOTIMESTAMPS, |
| .priv_data_size = sizeof(MSPContext), |
| }; |