shithub: opus

--- a/doc/draft-ietf-codec-opus.xml

+++ b/doc/draft-ietf-codec-opus.xml

@@ -60,7 +60,7 @@

 We propose the Opus codec based on a linear prediction layer (LP) and an

 MDCT-based layer. The main idea behind the proposal is that

 the speech low frequencies are usually more efficiently coded using

-linear prediction codecs (such as CELP variants), while the higher frequencies

+linear prediction codecs (such as CELP variants), while music and higher speech frequencies

 are more efficiently coded in the transform domain (e.g. MDCT). For low

 sampling rates, the MDCT layer is not useful and only the LP-based layer is

 used. On the other hand, non-speech signals are not always adequately coded

@@ -68,15 +68,13 @@

 </t>

<t>

-In this proposed prototype, the LP layer is based on the

+The Opus LP layer is based on the

 <eref target='http://developer.skype.com/silk'>SILK</eref> codec

-<xref target="SILK"></xref> and the MDCT layer is based on the

+<xref target="SILK"></xref> while the MDCT layer is based on the

 <eref target='http://www.celt-codec.org/'>CELT</eref>  codec

  <xref target="CELT"></xref>.

 </t>

-<t>This is a work in progress.</t>

 <t>The primary normative part of this specification is provided by the source

 code part of the document. The codec contains significant amounts of fixed-point

 arithmetic which must be performed exactly, including all rounding considerations,

@@ -728,7 +726,7 @@

 maximum allocation vector, decoding the boosts, decoding the tilt, determining

 the remaining capacity the frame, searching the mode table for the

 entry nearest but not exceeding the available space (subject to the tilt, boosts, band

-maximums, and band minimums), linear interpolation, reallocation of

+maxima, and band minima), linear interpolation, reallocation of

 unused bits with concurrent skip decoding, determination of the

 fine-energy vs shape split, and final reallocation. This process results

 in an shape allocation per-band (in 1/8th bit units), a per-band fine-energy

@@ -743,14 +741,14 @@

 to entropy coding of splitting parameters). Setting the maximum too low reduces the

 maximum achievable quality in a band while setting it too high

 may result in waste: bit-stream capacity available at the end

-of the frame which can not be put to any use. The maximums

+of the frame which can not be put to any use. The maxima

 specified by the codec reflect the average maximum. In the reference

-the maximums are provided partially computed form, in order to fit in less

+the maxima are provided partially computed form, in order to fit in less

 memory, as a static table (XXX cache.caps). Implementations are expected

 to simply use the same table data but the procedure for generating

 this table is included in rate.c as part of compute_pulse_cache().</t>

-<t>To convert the values in cache.caps into the actual maximums: First

+<t>To convert the values in cache.caps into the actual maxima: First

 set nbBands to the maximum number of bands for this mode and stereo to

 zero if stereo is not in use and one otherwise. For each band assign N

 to the number of MDCT bins covered by the band (for one channel), set LM