Add pass through support for Opus and VP8; Opus format attribute negotiation

This patch adds pass through support for Opus and VP8. That includes:

* Format attribute negotiation for Opus. Note that unlike some other codecs,
  the draft RFC specifies having spaces delimiting the attributes in addition
  to ';', so you have "attra=X; attrb=Y". This broke the attribute parsing in
  chan_sip, so a small tweak was also included in this patch for that.

* A format attribute negotiation module for Opus, res_format_attr_opus

* Fast picture update for VP8. Since VP8 uses a different RTCP packet number
  than FIR, this really is specific to VP8 at this time.

Note that the format attribute negotiation in res_pjsip_sdp_rtp was written
by mjordan. The rest of this patch was written completely by Lorenzo Miniero.

Review: https://reviewboard.asterisk.org/r/2723/

(closes issue ASTERISK-21981)
Reported by: Tzafrir Cohen
patches:
  asterisk_opus+vp8_passthrough_20130718.patch uploaded by lminiero (License 6518)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@397526 65c4cc65-6c06-0410-ace0-fbb531ad65f3

2 files changed, 46 insertions, 0 deletions

diff --git a/include/asterisk/format.h b/include/asterisk/format.h
index ab7d8eefb..885c62b2d 100644
--- a/include/asterisk/format.h
+++ b/include/asterisk/format.h
@@ -29,6 +29,7 @@
 #include "asterisk/astobj2.h"
 #include "asterisk/silk.h"
 #include "asterisk/celt.h"
+#include "asterisk/opus.h"
 #define AST_FORMAT_ATTR_SIZE 64
 #define AST_FORMAT_INC 100000
 
@@ -101,6 +102,8 @@ enum ast_format_id {
 	AST_FORMAT_SLINEAR192       = 27 + AST_FORMAT_TYPE_AUDIO,
 	AST_FORMAT_SPEEX32          = 28 + AST_FORMAT_TYPE_AUDIO,
 	AST_FORMAT_CELT             = 29 + AST_FORMAT_TYPE_AUDIO,
+	/*! Opus */
+	AST_FORMAT_OPUS             = 30 + AST_FORMAT_TYPE_AUDIO,
 
 	/*! H.261 Video */
 	AST_FORMAT_H261             = 1 + AST_FORMAT_TYPE_VIDEO,
@@ -112,6 +115,8 @@ enum ast_format_id {
 	AST_FORMAT_H264             = 4 + AST_FORMAT_TYPE_VIDEO,
 	/*! MPEG4 Video */
 	AST_FORMAT_MP4_VIDEO        = 5 + AST_FORMAT_TYPE_VIDEO,
+	/*! VP8 */
+	AST_FORMAT_VP8              = 6 + AST_FORMAT_TYPE_VIDEO,
 
 	/*! JPEG Images */
 	AST_FORMAT_JPEG             = 1 + AST_FORMAT_TYPE_IMAGE,
diff --git a/include/asterisk/opus.h b/include/asterisk/opus.h
new file mode 100644
index 000000000..0fbcfa10e
--- /dev/null
+++ b/include/asterisk/opus.h
@@ -0,0 +1,41 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * Lorenzo Miniero <lorenzo@meetecho.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \brief Opus Format Attributes (http://tools.ietf.org/html/draft-ietf-payload-rtp-opus)
+ *
+ * \author Lorenzo Miniero <lorenzo@meetecho.com>
+ */
+#ifndef _AST_FORMAT_OPUS_H_
+#define _AST_FORMAT_OPUS_H_
+
+/*! Opus format attribute key value pairs, all are accessible through ast_format_get_value()*/
+enum opus_attr_keys {
+	OPUS_ATTR_KEY_MAX_BITRATE, /*! value is an int (6000-510000 in spec). */
+	OPUS_ATTR_KEY_MAX_PLAYRATE, /*! value is an int (8000-48000), maximum output rate the receiver can render. */
+	OPUS_ATTR_KEY_MINPTIME, /*! value is an int (3-120 in spec, 10-60 in format.c), decoder's minimum length of time in milliseconds. */
+	OPUS_ATTR_KEY_STEREO, /*! value is an int, 1 prefer receiving stereo, 0 prefer mono. */
+	OPUS_ATTR_KEY_CBR, /*! value is an int, 1 use constant bitrate, 0 use variable bitrate. */
+	OPUS_ATTR_KEY_FEC, /*! value is an int, 1 encode with FEC, 0 do not use FEC. */
+	OPUS_ATTR_KEY_DTX, /*! value is an int, 1 dtx is enabled, 0 dtx not enabled. */
+	OPUS_ATTR_KEY_SPROP_CAPTURE_RATE, /*! value is an int (8000-48000), likely input rate we're going to produce. */
+	OPUS_ATTR_KEY_SPROP_STEREO, /*! value is an int, 1 likely to send stereo, 0 likely to send mono. */
+};
+
+#endif /* _AST_FORMAT_OPUS_H */