diff options
author | Jean-Marc Valin <jean-marc.valin@octasic.com> | 2009-07-02 23:04:59 +0400 |
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committer | Jean-Marc Valin <jean-marc.valin@octasic.com> | 2009-07-02 23:04:59 +0400 |
commit | f727386100e8021bf2bf27a746220419b2124c85 (patch) | |
tree | ab96ca7b23bc8e8de26911cf100c6aa55b0236c4 /doc | |
parent | 08192e317c23f8e2752efe53b016b0a21f483fc2 (diff) |
ietf doc: folding, VBR, misc
Diffstat (limited to 'doc')
-rw-r--r-- | doc/ietf/draft-valin-celt-codec.xml | 26 | ||||
-rw-r--r-- | doc/ietf/wrap_lines.c | 34 |
2 files changed, 57 insertions, 3 deletions
diff --git a/doc/ietf/draft-valin-celt-codec.xml b/doc/ietf/draft-valin-celt-codec.xml index 405d49b..a7a59ee 100644 --- a/doc/ietf/draft-valin-celt-codec.xml +++ b/doc/ietf/draft-valin-celt-codec.xml @@ -528,6 +528,21 @@ and if a sufficient number of bands have a high enough gain, then the pitch bit Otherwise, no use of pitch is made. </t> +<t> +For frequencies above the highest pitch band (~6374 Hz), the prediction is replaced by +spectral folding if and only if the folding bit is set (otherwise, the prediction is simply zero). +The folding prediction uses the quantised spectrum at lower frequencies with a gain that depends +both on the width of the band N and the number of pulses allocated K: +</t> + +<t> +g = N / (N + kf * K), +</t> + +<t> +where kf = 6. +</t> + </section> <section anchor="pvq" title="Spherical Vector Quantization"> @@ -643,7 +658,7 @@ the pitch predictor for the next few frames. <section anchor="vbr" title="Variable Bitrate (VBR)"> <t> -Each CELT frame can be encoded in a different number of octets, making it possible to vary the bitrate at will. This property can be used to implement source-controlled variable bitrate (VBR). +Each CELT frame can be encoded in a different number of octets, making it possible to vary the bitrate at will. This property can be used to implement source-controlled variable bitrate (VBR). Support for VBR is OPTIONAL for the encoder, but a decoder MUST be prepared to decode a stream that changes its bit-rate dynamically. The method used to vary the bit-rate in VBR mode is left to the implementor, as long as each frame can be decoded by the reference decoder. </t> </section> @@ -803,12 +818,17 @@ Insert some text here. --> +<section title="IANA Considerations "> +<t> +This document has no actions for IANA. +</t> +</section> + <section anchor="Acknowledgments" title="Acknowledgments"> <t> -The authors would also like to thank the following members of the -CELT and AVT communities for their input: +The authors would also like to thank the CELT users who contributed source code, feature requests, suggestions or comments. </t> </section> diff --git a/doc/ietf/wrap_lines.c b/doc/ietf/wrap_lines.c new file mode 100644 index 0000000..c78fde5 --- /dev/null +++ b/doc/ietf/wrap_lines.c @@ -0,0 +1,34 @@ +#include <string.h> +#include <stdio.h> + +int main() +{ + int comment = 0; + int col = 0; + char c0, c1; + c0 = getchar(); + while (!feof(stdin)) + { + c1 = getchar(); + if (c1==9) + c1 = 32; + if (col < 71 || c0 == 10) { + putchar(c0); + } else { + if (c1 == 10 || c1 == 13) + { + putchar(c0); + } else { + putchar ('\\'); + /*printf ("%d %d %d", col, c0, c1);*/ + putchar (10); + putchar (c0); + col=0; + } + } + col++; + if (c0 == 10) + col=0; + c0 = c1; + } +}
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