From e95de9a24411046f51b121b47b7de8ece6abfbd8 Mon Sep 17 00:00:00 2001 From: Jean-Marc Valin Date: Mon, 11 May 2009 12:53:46 -0400 Subject: [PATCH] Updated RTP draft --- doc/ietf/draft-valin-celt-rtp-profile.xml | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/doc/ietf/draft-valin-celt-rtp-profile.xml b/doc/ietf/draft-valin-celt-rtp-profile.xml index a5c45bfe..95596cca 100644 --- a/doc/ietf/draft-valin-celt-rtp-profile.xml +++ b/doc/ietf/draft-valin-celt-rtp-profile.xml @@ -438,24 +438,20 @@ headers and the length bytes). The value MUST be rounded to an integer number of bytes per frame. The round-to-nearest method is RECOMMENDED. The default bit-rate value is 64 kbit/s per channel. -frame-size: The frame size is the duration of each frame in samples. If more than one frame size is supported, a comma-separated list can be used. It is possible to use "any" to denote that -all even frame sizes are supported. The default is 480. +frame-size: The frame size is the duration of each frame in samples and has to be even. +The default is 480. mapping: Optional string describing the multi-channel mapping. -Because the frame-size is not transmitted in-band, an SDP answer MUST -contain only one frame-size, even if multiple frame sizes were offered. - - The selected frame-size values MUST be even. For quality and complexity reasons, they SHOULD also be divisible by 8 and have a prime factorization which consists only of 2, 3, or 5 factors. For example, powers-of-two and values such as 160, 320, 240, and 480 are recommended. Implementations MUST support receiving and sending the default -value of 480, and if the size 480 is supported it MUST be offered. Implementations +value of 480. Implementations SHOULD also support frame sizes of 256 and 512 since these are the ones that lead to the lowest complexity. When frame sizes that are powers-of-two are supported, they SHOULD be listed first in the offer and chosen over non-powers-of-two in the @@ -571,7 +567,7 @@ For example a stereo configuration might signal: m=audio 8008 RTP/AVP 97 a=ptime: 5 a=rtpmap:97 CELT/44100/2 -a=fmtp:97 frame-size=256; +a=fmtp:97 frame-size=256 Which specifies a single two-channel CELT stream according to the default mapping.