[FFmpeg-devel] avformat: add DAT CCTV demuxer

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 5ce1e6464d..b4cc467268 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -292,6 +292,7 @@  OBJS-$(CONFIG_KVAG_MUXER)                += kvag.o rawenc.o
 OBJS-$(CONFIG_LATM_MUXER)                += latmenc.o rawenc.o
 OBJS-$(CONFIG_LMLM4_DEMUXER)             += lmlm4.o
 OBJS-$(CONFIG_LOAS_DEMUXER)              += loasdec.o rawdec.o
+OBJS-$(CONFIG_LUODAT_DEMUXER)            += luodatdec.o
 OBJS-$(CONFIG_LRC_DEMUXER)               += lrcdec.o lrc.o subtitles.o
 OBJS-$(CONFIG_LRC_MUXER)                 += lrcenc.o lrc.o
 OBJS-$(CONFIG_LVF_DEMUXER)               += lvfdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 82838e3c53..a23eb9e7fa 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -226,6 +226,7 @@  extern AVOutputFormat ff_kvag_muxer;
 extern AVOutputFormat ff_latm_muxer;
 extern AVInputFormat  ff_lmlm4_demuxer;
 extern AVInputFormat  ff_loas_demuxer;
+extern AVInputFormat  ff_luodat_demuxer;
 extern AVInputFormat  ff_lrc_demuxer;
 extern AVOutputFormat ff_lrc_muxer;
 extern AVInputFormat  ff_lvf_demuxer;
diff --git a/libavformat/luodatdec.c b/libavformat/luodatdec.c
new file mode 100644
index 0000000000..939c7f63b5
--- /dev/null
+++ b/libavformat/luodatdec.c
@@ -0,0 +1,129 @@ 
+/*
+ * CCTV DAT demuxer
+ *
+ * Copyright (c) 2020 Paul B Mahol
+ *
+ * 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
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avio_internal.h"
+#include "avformat.h"
+#include "internal.h"
+
+static int dat_probe(const AVProbeData *p)
+{
+    if (p->buf_size < 0x2080)
+        return 0;
+
+    if (memcmp(p->buf, "luo ", 4))
+        return 0;
+
+    if (memcmp(p->buf + 0x1ffc, " oul", 4))
+        return 0;
+
+    if (memcmp(p->buf + 0x2000, "liu ", 4))
+        return 0;
+
+    if (!AV_RL32(p->buf + 0x2004))
+        return 0;
+
+    if (memcmp(p->buf + 0x207c, " uil", 4))
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int dat_read_header(AVFormatContext *s)
+{
+    s->ctx_flags |= AVFMTCTX_NOHEADER;
+
+    avio_seek(s->pb, 0x2000, SEEK_SET);
+
+    return 0;
+}
+
+static int dat_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVIOContext *pb = s->pb;
+    int index, ret, key, stream_id, stream_index, width, height, fps, pkt_size;
+    int64_t pts, pos = avio_tell(pb);
+
+    if (avio_feof(pb))
+        return AVERROR_EOF;
+
+    if (avio_rb32(pb) != MKBETAG('l', 'i', 'u', ' '))
+        return AVERROR_INVALIDDATA;
+    stream_id = avio_rl32(pb);
+    width     = avio_rl32(pb);
+    height    = avio_rl32(pb);
+    fps       = avio_rl32(pb);
+    avio_skip(pb, 16);
+    key       = avio_rl32(pb) == 1;
+    avio_skip(pb, 4);
+    index     = avio_rl32(pb);
+    avio_skip(pb, 4);
+    pts       = avio_rl64(pb);
+    pkt_size  = avio_rl32(pb);
+    avio_skip(pb, 64);
+
+    if (pkt_size == 0)
+        return AVERROR_EOF;
+
+    for (stream_index = 0; stream_index < s->nb_streams; stream_index++) {
+        if (s->streams[stream_index]->id == stream_id)
+            break;
+    }
+
+    if (stream_index == s->nb_streams) {
+        AVStream *st = avformat_new_stream(s, NULL);
+
+        if (!st)
+            return AVERROR(ENOMEM);
+
+        st->id = stream_id;
+        st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
+        st->codecpar->codec_id   = AV_CODEC_ID_H264;
+        st->codecpar->width      = width;
+        st->codecpar->height     = height;
+        avpriv_set_pts_info(st, 64, 1, fps);
+    }
+
+    if (index >= s->nb_streams)
+        av_log(s, AV_LOG_WARNING, "Stream index out of range.\n");
+
+    ret = av_get_packet(pb, pkt, pkt_size);
+    if (ret < 0)
+        return ret;
+    pkt->pos = pos;
+    pkt->pts = pts;
+    pkt->stream_index = stream_index;
+    if (key)
+        pkt->flags |= AV_PKT_FLAG_KEY;
+
+    return ret;
+}
+
+AVInputFormat ff_luodat_demuxer = {
+    .name           = "luodat",
+    .long_name      = NULL_IF_CONFIG_SMALL("Video DAT"),
+    .read_probe     = dat_probe,
+    .read_header    = dat_read_header,
+    .read_packet    = dat_read_packet,
+    .extensions     = "dat",
+    .flags          = AVFMT_GENERIC_INDEX,
+};