Ogg: add support for Xiph's CELT (Opus) codec.

This patch also introduces CODEC_ID_CELT.

Signed-off-by: Nicolas George <nicolas.george@normalesup.org>

libavcodec/avcodec.h

@@ -342,6 +342,7 @@ enum CodecID {
     CODEC_ID_BINKAUDIO_DCT,
     CODEC_ID_AAC_LATM,
     CODEC_ID_QDMC,
+    CODEC_ID_CELT,
 
     /* subtitle codecs */
     CODEC_ID_DVD_SUBTITLE= 0x17000,

libavformat/Makefile

@@ -164,6 +164,7 @@ OBJS-$(CONFIG_NUT_DEMUXER)               += nutdec.o nut.o riff.o
 OBJS-$(CONFIG_NUT_MUXER)                 += nutenc.o nut.o riff.o
 OBJS-$(CONFIG_NUV_DEMUXER)               += nuv.o riff.o
 OBJS-$(CONFIG_OGG_DEMUXER)               += oggdec.o         \
+                                            oggparsecelt.o   \
                                             oggparsedirac.o  \
                                             oggparseflac.o   \
                                             oggparseogm.o    \

libavformat/oggdec.c

@@ -45,6 +45,7 @@ static const struct ogg_codec * const ogg_codecs[] = {
     &ff_vorbis_codec,
     &ff_theora_codec,
     &ff_flac_codec,
+    &ff_celt_codec,
     &ff_old_dirac_codec,
     &ff_old_flac_codec,
     &ff_ogm_video_codec,

libavformat/oggdec.h

@@ -98,6 +98,7 @@ struct ogg {
 #define OGG_FLAG_BOS  2
 #define OGG_FLAG_EOS  4
 
+extern const struct ogg_codec ff_celt_codec;
 extern const struct ogg_codec ff_dirac_codec;
 extern const struct ogg_codec ff_flac_codec;
 extern const struct ogg_codec ff_ogm_audio_codec;

libavformat/oggparsecelt.c

@@ -0,0 +1,99 @@
+/*
+ * Xiph CELT / Opus parser for Ogg
+ * Copyright (c) 2011 Nicolas George
+ *
+ * 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 <string.h>
+#include "avformat.h"
+#include "oggdec.h"
+#include "libavutil/intreadwrite.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, header_size, sample_rate, nb_channels, frame_size;
+        uint32_t overlap, bytes_per_packet, 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);
+        header_size      = AV_RL32(p + 32); /* unused */
+        sample_rate      = AV_RL32(p + 36);
+        nb_channels      = AV_RL32(p + 40);
+        frame_size       = AV_RL32(p + 44);
+        overlap          = AV_RL32(p + 48);
+        bytes_per_packet = AV_RL32(p + 52); /* unused */
+        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,
+};

libavformat/utils.c

@@ -2084,7 +2084,8 @@ static int has_codec_parameters(AVCodecContext *enc)
             enc->codec_id == CODEC_ID_MP1 ||
             enc->codec_id == CODEC_ID_MP2 ||
             enc->codec_id == CODEC_ID_MP3 ||
-            enc->codec_id == CODEC_ID_SPEEX))
+            enc->codec_id == CODEC_ID_SPEEX ||
+            enc->codec_id == CODEC_ID_CELT))
             return 0;
         break;
     case AVMEDIA_TYPE_VIDEO: