From 24ca518bd1553e2e73d31b9f93df4fb7219606ff Mon Sep 17 00:00:00 2001
From: David Conrad <lessen42@gmail.com>
Date: Mon, 11 Jan 2010 00:31:52 +0000
Subject: Add support for dirac in ogg

Originally committed as revision 21128 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavformat/oggparsedirac.c | 109 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 libavformat/oggparsedirac.c

(limited to 'libavformat/oggparsedirac.c')

diff --git a/libavformat/oggparsedirac.c b/libavformat/oggparsedirac.c
new file mode 100644
index 0000000000..fc1a193205
--- /dev/null
+++ b/libavformat/oggparsedirac.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2008  David Conrad
+ *
+ * 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 "libavcodec/get_bits.h"
+#include "libavcodec/dirac.h"
+#include "avformat.h"
+#include "oggdec.h"
+
+static int dirac_header(AVFormatContext *s, int idx)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os = ogg->streams + idx;
+    AVStream *st = s->streams[idx];
+    dirac_source_params source;
+    GetBitContext gb;
+
+    // already parsed the header
+    if (st->codec->codec_id == CODEC_ID_DIRAC)
+        return 0;
+
+    init_get_bits(&gb, os->buf + os->pstart + 13, (os->psize - 13) * 8);
+    if (ff_dirac_parse_sequence_header(st->codec, &gb, &source) < 0)
+        return -1;
+
+    st->codec->codec_type = CODEC_TYPE_VIDEO;
+    st->codec->codec_id = CODEC_ID_DIRAC;
+    // dirac in ogg always stores timestamps as though the video were interlaced
+    st->time_base = (AVRational){st->codec->time_base.num, 2*st->codec->time_base.den};
+    return 1;
+}
+
+// various undocument things: granule is signed (only for dirac!)
+static uint64_t dirac_gptopts(AVFormatContext *s, int idx, int64_t gp)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os = ogg->streams + idx;
+
+    unsigned dist  = ((gp >> 14) & 0xff00) | (gp & 0xff);
+    int64_t  dts   = (gp >> 31);
+    int64_t  pts   = dts + ((gp >> 9) & 0x1fff);
+
+    if (!dist)
+        os->pflags |= PKT_FLAG_KEY;
+
+    return pts;
+}
+
+static int old_dirac_header(AVFormatContext *s, int idx)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os = ogg->streams + idx;
+    AVStream *st = s->streams[idx];
+    uint8_t *buf = os->buf + os->pstart;
+
+    if (buf[0] != 'K')
+        return 0;
+
+    st->codec->codec_type = CODEC_TYPE_VIDEO;
+    st->codec->codec_id = CODEC_ID_DIRAC;
+    st->time_base.den = AV_RB32(buf+8);
+    st->time_base.num = AV_RB32(buf+12);
+    return 1;
+}
+
+static uint64_t old_dirac_gptopts(AVFormatContext *s, int idx, uint64_t gp)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os = ogg->streams + idx;
+    uint64_t iframe = gp >> 30;
+    uint64_t pframe = gp & 0x3fffffff;
+
+    if (!pframe)
+        os->pflags |= PKT_FLAG_KEY;
+
+    return iframe + pframe;
+}
+
+const struct ogg_codec ff_dirac_codec = {
+    .magic = "BBCD\0",
+    .magicsize = 5,
+    .header = dirac_header,
+    .gptopts = dirac_gptopts,
+    .granule_is_start = 1,
+};
+
+const struct ogg_codec ff_old_dirac_codec = {
+    .magic = "KW-DIRAC",
+    .magicsize = 8,
+    .header = old_dirac_header,
+    .gptopts = old_dirac_gptopts,
+    .granule_is_start = 1,
+};
-- 
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