[FFmpeg-devel] [PATCH 1/3] avformat/mspdec: Microsoft Paint (MSP) demuxer
Peter Ross
pross at xvid.org
Thu Oct 8 14:02:02 EEST 2020
Signed-off-by: Peter Ross <pross at xvid.org>
---
Week nine or so of lockdown...
Changelog | 1 +
doc/general_contents.texi | 2 +
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/mspdec.c | 95 +++++++++++++++++++++++++++++++++++++++
5 files changed, 100 insertions(+)
create mode 100644 libavformat/mspdec.c
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
+ at 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 at 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),
+};
--
2.28.0
-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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