diff options
author | Jean-Marc Valin <jean-marc.valin@octasic.com> | 2009-07-03 21:03:51 +0400 |
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committer | Jean-Marc Valin <jean-marc.valin@octasic.com> | 2009-07-03 21:03:51 +0400 |
commit | 23375a8933a627627344c8b1963153e0b71a3ffa (patch) | |
tree | d5258005998f5dd843d5a76fbdcee634852a692f /doc | |
parent | 6fa4b56ba891c871c5d54a50703ca3d5bfda11d3 (diff) |
ietf doc: s/bytes/octet/
Diffstat (limited to 'doc')
-rw-r--r-- | doc/ietf/draft-valin-celt-codec.xml | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/doc/ietf/draft-valin-celt-codec.xml b/doc/ietf/draft-valin-celt-codec.xml index 11026bb..55ac109 100644 --- a/doc/ietf/draft-valin-celt-codec.xml +++ b/doc/ietf/draft-valin-celt-codec.xml @@ -89,7 +89,7 @@ cost. <t>The novel aspect of CELT compared to most other codecs is its very low delay, below 10 ms. There are two main advantages to having a very low delay audio link. -The lower delay itself is important some interactions, such as playing music +The lower delay itself is important for some interactions, such as playing music remotely. Another advantage is the behavior in presence of acoustic echo. When the round-trip audio delay is sufficiently low, acoustic echo is no longer perceived as a distinct repetition, but as extra reverberation. Applications @@ -332,7 +332,7 @@ CELT uses an entropy coder based upon <xref target="range-coding"></xref>, which is itself a rediscovery of the FIFO arithmetic code introduced by <xref target="coding-thesis"></xref>. It is very similar to arithmetic encoding, except that encoding is done with digits in any base, instead of with bits, -so it is faster when using larger bases (i.e.: a byte). All of the +so it is faster when using larger bases (i.e.: an octet). All of the calculations in the range coder must use bit-exact integer arithmetic. </t> @@ -349,9 +349,9 @@ used in three different ways, to encode: <t> The range encoder maintains an internal state vector composed of the four-tuple (low,rng,rem,ext), representing the low end of the current -range, the size of the current range, a single buffered output byte, -and a count of additional carry-propagating output bytes. Both rng -and low are 32-bit unsigned integer values, rem is a byte value, or +range, the size of the current range, a single buffered output octet, +and a count of additional carry-propagating output octets. Both rng +and low are 32-bit unsigned integer values, rem is an octet value, or the special value -1, and ext is an integer with at least 16 bits. This state vector is initialized at the start of each each frame to the value (0,2^31,-1,0). @@ -397,16 +397,16 @@ fl=sum(f(i),i<k), fh=fl+f(i), and ft=sum(f(i)). consist of 8 data bits and a carry flag. The final value of the output bits is not determined until carry propagation is accounted for. Therefore the reference implementation buffers a single - (non-propagating) output byte and keeps a count of additional - propagating (0xFF) output bytes. An implementation MAY choose to use + (non-propagating) output octet and keeps a count of additional + propagating (0xFF) output octets. An implementation MAY choose to use any mathematically equivalent scheme to perform carry propagation. </t> <t> The function ec_enc_carry_out() (<xref target="rangeenc.c">rangeenc.c</xref>) performs this buffering. It takes a 9-bit input value, c, from the normalization 8-bit output and a carry bit. If c is 0xFF, then ext is incremented - and no bytes are output. Otherwise, if rem is not the special value - -1, then the byte (rem+(c>>8)) is output. Then ext bytes are output + and no octets are output. Otherwise, if rem is not the special value + -1, then the octet (rem+(c>>8)) is output. Then ext octets are output with the value 0 if the carry bit is set, or 0xFF if it is not, and rem is set to the lower 8 bits of c. After this, ext is set to zero </t> @@ -459,8 +459,8 @@ fl=sum(f(i),i<k), fh=fl+f(i), and ft=sum(f(i)). (end<<8&0x7FFFFFFF). Finally, if the value in carry buffer, rem, is]]> neither zero nor the special value -1, or the carry count, ext, is greater than zero, then 9 zero bits are sent to the carry buffer. - After the carry buffer is finished outputting bytes, the rest of the - output buffer is padded with zero bytes. Finally, rem is set to the + After the carry buffer is finished outputting octets, the rest of the + output buffer is padded with zero octets. Finally, rem is set to the special value -1. This process is implemented by ec_enc_done() (<xref target="rangeenc.c">rangeenc.c</xref>). </t> @@ -866,7 +866,7 @@ difference between the high end of the current range and the actual coded value, and the size of the current range, respectively. Both
dif and rng are 32-bit unsigned integer values. rng is initialized to
2^7. dif is initialized to rng minus the top 7 bits of the first
-input byte. Then the range is immediately normalized, using the
+input octet. Then the range is immediately normalized, using the
procedure described in the following section. </t> @@ -904,8 +904,8 @@ procedure described in the following section. To normalize the range, the following process is repeated until
rng > 2^23. First, rng is set to (rng<8)&0xFFFFFFFF. Then, the next
8 bits of input are read into sym, using the remaining bit from the
- previous input byte as the high bit of sym, and the top 7 bits of the
- next byte for the remaining bits of sym. If no more input bytes
+ previous input octet as the high bit of sym, and the top 7 bits of the
+ next octet for the remaining bits of sym. If no more input octets
remain, zero bits are used instead. Then, dif is set to
(dif<<8)-sym&0xFFFFFFFF (i.e., using wrap-around if the subtraction
overflows a 32-bit register). Finally, if dif is larger than 2^31,
@@ -1224,13 +1224,13 @@ The testcelt executable can be used to test the encoding and decoding process: <list style="empty"> <t><![CDATA[ -testcelt <rate> <channels> <frame size> <bytes per packet> +testcelt <rate> <channels> <frame size> <octets per packet> [<complexity> [packet loss rate]] <input> <output> ]]></t> </list> where "rate" is the sampling rate in Hz, "channels" is the number of channels (1 or 2), "frame size" is the number of samples in a frame -(64 to 512) and "bytes per packet" is the number of bytes desired for each +(64 to 512) and "octets per packet" is the number of octets desired for each compressed frame. The input and output files are assumed to be a 16-bit PCM file in the machine native endianness. The optional "complexity" argument can select the quality vs complexity tradeoff (0-10) and the "packet loss rate" |