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| author | Ralph Giles <giles@thaumas.net> | 2015-11-16 13:31:09 -0800 |
|---|---|---|
| committer | Ralph Giles <giles@thaumas.net> | 2015-11-16 13:32:01 -0800 |
| commit | f461335597803743cf589a6734ee7c1e6ecd51ff (patch) | |
| tree | 1dc7c915b0415d54e62b45833014d6dba730338f | |
| parent | ac6c6c1001f7e8af77f4acee1229fd148e2356a2 (diff) | |
| download | opus-f461335597803743cf589a6734ee7c1e6ecd51ff.tar.gz | |
oggopus: Consolidate granulepos description.
Based on Mo Zanaty's review comments.
| -rw-r--r-- | doc/draft-ietf-codec-oggopus.xml | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/doc/draft-ietf-codec-oggopus.xml b/doc/draft-ietf-codec-oggopus.xml index d929fa0b..e3eadc93 100644 --- a/doc/draft-ietf-codec-oggopus.xml +++ b/doc/draft-ietf-codec-oggopus.xml @@ -143,7 +143,6 @@ An Ogg Opus stream is organized as follows. </t> <t> There are two mandatory header packets. -The granule position of the pages on which these packets complete MUST be zero. </t> <t> The first packet in the logical Ogg bitstream MUST contain the identification @@ -157,7 +156,7 @@ This page MUST have its 'beginning of stream' flag set. The second packet in the logical Ogg bitstream MUST contain the comment header, which contains user-supplied metadata. The format of this header is defined in <xref target="comment_header"/>. -It MAY span one or more pages, beginning on the second page of the logical +It MAY span multiple pages, beginning on the second page of the logical stream. However many pages it spans, the comment header packet MUST finish the page on which it completes. @@ -214,9 +213,20 @@ There MUST NOT be any more pages in an Opus logical bitstream after a page <section anchor="granpos" title="Granule Position"> <t> +The granule position MUST be zero for the ID header page and the + page where the comment header completes. +That is, the first page in the logical stream, and the last header + page before the first audio data page both have zero granulepos. +</t> +<t> The granule position of an audio data page encodes the total number of PCM samples in the stream up to and including the last fully-decodable sample from the last packet completed on that page. +That granule position MAY be larger than zero as described in + <xref target="start_granpos_restrictions"/>. +</t> + +<t> A page that is entirely spanned by a single packet (that completes on a subsequent page) has no granule position, and the granule position field MUST be set to the special value '-1' in two's complement. |