[FFmpeg-devel,1/2] avformat/ildadec: ILDA Image Data Transfer Format demuxer

diff --git a/doc/general_contents.texi b/doc/general_contents.texi
index 86ec6d606b..935101af6e 100644
--- a/doc/general_contents.texi
+++ b/doc/general_contents.texi
@@ -500,6 +500,7 @@  library:
 @item IFV                       @tab   @tab X
     @tab A format used by some old CCTV DVRs.
 @item iLBC                      @tab X @tab X
+@item ILDA Image Data Transfer Format @tab @tab X
 @item Interplay MVE             @tab   @tab X
     @tab Format used in various Interplay computer games.
 @item Iterated Systems ClearVideo @tab     @tab  X
diff --git a/libavformat/Makefile b/libavformat/Makefile
index f67a99f839..706edab6b1 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -260,6 +260,7 @@  OBJS-$(CONFIG_IFF_DEMUXER)               += iff.o
 OBJS-$(CONFIG_IFV_DEMUXER)               += ifv.o
 OBJS-$(CONFIG_ILBC_DEMUXER)              += ilbc.o
 OBJS-$(CONFIG_ILBC_MUXER)                += ilbc.o rawenc.o
+OBJS-$(CONFIG_ILDA_DEMUXER)              += ildadec.o
 OBJS-$(CONFIG_IMAGE2_DEMUXER)            += img2dec.o img2.o
 OBJS-$(CONFIG_IMAGE2_MUXER)              += img2enc.o img2.o
 OBJS-$(CONFIG_IMAGE2PIPE_DEMUXER)        += img2dec.o img2.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index ae4479fb7a..6ff2b0a3c2 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -210,6 +210,7 @@  extern const AVInputFormat  ff_iff_demuxer;
 extern const AVInputFormat  ff_ifv_demuxer;
 extern const AVInputFormat  ff_ilbc_demuxer;
 extern const AVOutputFormat ff_ilbc_muxer;
+extern const AVInputFormat  ff_ilda_demuxer;
 extern const AVInputFormat  ff_image2_demuxer;
 extern const AVOutputFormat ff_image2_muxer;
 extern const AVInputFormat  ff_image2pipe_demuxer;
diff --git a/libavformat/ildadec.c b/libavformat/ildadec.c
new file mode 100644
index 0000000000..ad2563f281
--- /dev/null
+++ b/libavformat/ildadec.c
@@ -0,0 +1,137 @@ 
+/*
+ * ILDA Image Data Transfer Format 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
+ * ILDA Image Data Transfer Format demuxer
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "libavcodec/bytestream.h"
+#include "avformat.h"
+#include "internal.h"
+#include "libavutil/opt.h"
+
+typedef struct {
+    AVClass *class;
+    int width, height;
+    AVRational framerate;
+} ILDAContext;
+
+static const uint8_t record_size[] = {8, 6, 3, 3, 10, 8};
+
+static int probe(const AVProbeData *p)
+{
+    if (p->buf_size < 8 || memcmp(p->buf, "ILDA", 4) || p->buf[4] || p->buf[5] || p->buf[6] || p->buf[7] >= FF_ARRAY_ELEMS(record_size))
+        return 0;
+    return AVPROBE_SCORE_MAX / 4 + 1;
+}
+
+static int read_header(AVFormatContext *avctx)
+{
+    ILDAContext * s = avctx->priv_data;
+    AVStream *st = avformat_new_stream(avctx, NULL);
+
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
+    st->codecpar->codec_id   = AV_CODEC_ID_ILDA;
+
+    st->codecpar->width  = s->width;
+    st->codecpar->height = s->height;
+    avpriv_set_pts_info(st, 64, s->framerate.den, s->framerate.num);
+    st->avg_frame_rate = s->framerate;
+    return 0;
+}
+
+static int read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVIOContext *pb = s->pb;
+    uint8_t buf[32];
+    int type, nb_entries, ret;
+    int64_t pos;
+
+    if (avio_feof(pb))
+        return AVERROR_EOF;
+
+    pos = avio_tell(pb);
+
+    if (avio_read(pb, buf, sizeof(buf)) != sizeof(buf))
+        return AVERROR(EIO);
+
+    if (AV_RB32(buf) != MKBETAG('I', 'L', 'D', 'A')) {
+        av_log(s, AV_LOG_ERROR, "unexpected tag\n");
+        return AVERROR(EIO);
+    }
+
+    type = buf[7];
+    if (type >= FF_ARRAY_ELEMS(record_size))
+        return AVERROR(EIO);
+
+    nb_entries = AV_RB16(buf + 24);
+    if (!nb_entries) {
+        avio_seek(pb, -sizeof(buf), SEEK_CUR);
+        return AVERROR(EOF);
+    }
+
+    ret = av_new_packet(pkt, sizeof(buf) + nb_entries * record_size[type]);
+    if (ret < 0)
+        return ret;
+
+    memcpy(pkt->data, buf, sizeof(buf));
+
+    ret = avio_read(pb, pkt->data + sizeof(buf), nb_entries * record_size[type]);
+    if (ret < 0)
+       return ret;
+
+    pkt->pos = pos;
+    pkt->pts = AV_RB16(buf + 26);
+    pkt->flags |= AV_PKT_FLAG_KEY;
+
+    return 0;
+}
+
+#define OFFSET(x) offsetof(ILDAContext, x)
+#define DEC AV_OPT_FLAG_DECODING_PARAM
+static const AVOption options[] = {
+    { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
+    { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "10"}, 0, INT_MAX, DEC },
+    { NULL },
+};
+
+static const AVClass ilda_demuxer_class = {
+    .class_name     = "ILDA demuxer",
+    .item_name      = av_default_item_name,
+    .option         = options,
+    .version        = LIBAVUTIL_VERSION_INT,
+};
+
+AVInputFormat ff_ilda_demuxer = {
+    .name           = "ilda",
+    .long_name      = NULL_IF_CONFIG_SMALL("ILDA Image Data Transfer Format"),
+    .priv_data_size = sizeof(ILDAContext),
+    .read_probe     = probe,
+    .read_header    = read_header,
+    .read_packet    = read_packet,
+    .priv_class     = &ilda_demuxer_class,
+    .flags          = AVFMT_GENERIC_INDEX,
+};