oggdec: add support for Xiph's CELT codec

This patch also introduces CODEC_ID_CELT.

Signed-off-by: Nicolas George <nicolas.george@normalesup.org>
Signed-off-by: Diego Biurrun <diego@biurrun.de>

1 files changed, 96 insertions, 0 deletions

diff --git a/libavformat/oggparsecelt.c b/libavformat/oggparsecelt.c
new file mode 100644
index 0000000000..82a842c612
--- /dev/null
+++ b/libavformat/oggparsecelt.c
@@ -0,0 +1,96 @@
+/*
+ * Xiph CELT / Opus parser for Ogg
+ * Copyright (c) 2011 Nicolas George
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <string.h>
+
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+#include "oggdec.h"
+
+struct oggcelt_private {
+    int extra_headers_left;
+};
+
+static int celt_header(AVFormatContext *s, int idx)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os = ogg->streams + idx;
+    AVStream *st = s->streams[idx];
+    struct oggcelt_private *priv = os->private;
+    uint8_t *p = os->buf + os->pstart;
+
+    if (os->psize == 60 &&
+        !memcmp(p, ff_celt_codec.magic, ff_celt_codec.magicsize)) {
+        /* Main header */
+
+        uint32_t version, sample_rate, nb_channels, frame_size;
+        uint32_t overlap, extra_headers;
+        uint8_t *extradata;
+
+        extradata = av_malloc(2 * sizeof(uint32_t) +
+                              FF_INPUT_BUFFER_PADDING_SIZE);
+        priv = av_malloc(sizeof(struct oggcelt_private));
+        if (!extradata || !priv) {
+            av_free(extradata);
+            av_free(priv);
+            return AVERROR(ENOMEM);
+        }
+        version          = AV_RL32(p + 28);
+        /* unused header size field skipped */
+        sample_rate      = AV_RL32(p + 36);
+        nb_channels      = AV_RL32(p + 40);
+        frame_size       = AV_RL32(p + 44);
+        overlap          = AV_RL32(p + 48);
+        /* unused bytes per packet field skipped */
+        extra_headers    = AV_RL32(p + 56);
+        av_free(os->private);
+        av_free(st->codec->extradata);
+        st->codec->codec_type     = AVMEDIA_TYPE_AUDIO;
+        st->codec->codec_id       = CODEC_ID_CELT;
+        st->codec->sample_rate    = sample_rate;
+        st->codec->channels       = nb_channels;
+        st->codec->frame_size     = frame_size;
+        st->codec->sample_fmt     = AV_SAMPLE_FMT_S16;
+        st->codec->extradata      = extradata;
+        st->codec->extradata_size = 2 * sizeof(uint32_t);
+        if (sample_rate)
+            av_set_pts_info(st, 64, 1, sample_rate);
+        priv->extra_headers_left  = 1 + extra_headers;
+        os->private = priv;
+        AV_WL32(extradata + 0, overlap);
+        AV_WL32(extradata + 4, version);
+        return 1;
+    } else if (priv && priv->extra_headers_left) {
+        /* Extra headers (vorbiscomment) */
+
+        ff_vorbis_comment(s, &st->metadata, p, os->psize);
+        priv->extra_headers_left--;
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+const struct ogg_codec ff_celt_codec = {
+    .magic     = "CELT    ",
+    .magicsize = 8,
+    .header    = celt_header,
+};