[FFmpeg-devel,1/3] avformat/mspdec: Microsoft Paint (MSP) demuxer

diff --git a/Changelog b/Changelog
index 0ecda9ed52..84690791af 100644
--- a/Changelog
+++ b/Changelog
@@ -35,6 +35,7 @@  version <next>:
 - AVS3 demuxer
 - AVS3 video decoder via libuavs3d
 - Cintel RAW decoder
+- Microsoft Paint (MSP) demuxer
 
 
 version 4.3:
diff --git a/doc/general_contents.texi b/doc/general_contents.texi
index 598e0e74da..cd3391fc8d 100644
--- a/doc/general_contents.texi
+++ b/doc/general_contents.texi
@@ -727,6 +727,8 @@  following image formats are supported:
 @item JPEG-LS      @tab X @tab X
 @item LJPEG        @tab X @tab
     @tab Lossless JPEG
+@item MSP          @tab   @tab X
+    @tab Microsoft Paint image
 @item PAM          @tab X @tab X
     @tab PAM is a PNM extension with alpha support.
 @item PBM          @tab X @tab X
diff --git a/libavformat/Makefile b/libavformat/Makefile
index a5e8bddb87..5cf3db630e 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -352,6 +352,7 @@  OBJS-$(CONFIG_MPEGVIDEO_DEMUXER)         += mpegvideodec.o rawdec.o
 OBJS-$(CONFIG_MPJPEG_DEMUXER)            += mpjpegdec.o
 OBJS-$(CONFIG_MPJPEG_MUXER)              += mpjpeg.o
 OBJS-$(CONFIG_MPL2_DEMUXER)              += mpl2dec.o subtitles.o
+OBJS-$(CONFIG_MSP_DEMUXER)               += mspdec.o rawdec.o
 OBJS-$(CONFIG_MSF_DEMUXER)               += msf.o
 OBJS-$(CONFIG_MPSUB_DEMUXER)             += mpsubdec.o subtitles.o
 OBJS-$(CONFIG_MSNWC_TCP_DEMUXER)         += msnwc_tcp.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 96b9bc2a0c..1ba00439b9 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -282,6 +282,7 @@  extern AVInputFormat  ff_mpjpeg_demuxer;
 extern AVOutputFormat ff_mpjpeg_muxer;
 extern AVInputFormat  ff_mpl2_demuxer;
 extern AVInputFormat  ff_mpsub_demuxer;
+extern AVInputFormat  ff_msp_demuxer;
 extern AVInputFormat  ff_msf_demuxer;
 extern AVInputFormat  ff_msnwc_tcp_demuxer;
 extern AVInputFormat  ff_mtaf_demuxer;
diff --git a/libavformat/mspdec.c b/libavformat/mspdec.c
new file mode 100644
index 0000000000..8f67a82424
--- /dev/null
+++ b/libavformat/mspdec.c
@@ -0,0 +1,95 @@ 
+/*
+ * 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"
+#include "rawdec.h"
+
+static int msp_probe(const AVProbeData *p)
+{
+    unsigned int i, sum;
+
+    if (p->buf_size <= 32 || memcmp(p->buf, "DanM", 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)
+{
+    FFRawDemuxerContext * cntx = s->priv_data;
+    AVIOContext *pb = s->pb;
+    AVStream *st;
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    avio_skip(pb, 4);
+
+    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
+    st->codecpar->codec_id = s->iformat->raw_codec_id;
+    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);
+
+    cntx->raw_packet_size = av_image_get_buffer_size(st->codecpar->format, st->codecpar->width, st->codecpar->height, 1);
+    if (cntx->raw_packet_size < 0)
+        return cntx->raw_packet_size;
+
+    return 0;
+}
+
+static int msp_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    FFRawDemuxerContext *cntx = s->priv_data;
+    int ret = av_get_packet(s->pb, pkt, cntx->raw_packet_size);
+    if (ret < 0)
+        return ret;
+    pkt->stream_index = 0;
+    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_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,
+    .raw_codec_id = AV_CODEC_ID_RAWVIDEO,
+    .priv_data_size = sizeof(FFRawDemuxerContext),
+};