< draft-ietf-codec-opus-update-06.txt   draft-ietf-codec-opus-update-07.txt >
Network Working Group JM. Valin Network Working Group JM. Valin
Internet-Draft Mozilla Corporation Internet-Draft Mozilla Corporation
Intended status: Standards Track K. Vos Updates: 6716 (if approved) K. Vos
Expires: December 21, 2017 vocTone Intended status: Standards Track vocTone
June 19, 2017 Expires: January 17, 2018 July 16, 2017
Updates to the Opus Audio Codec Updates to the Opus Audio Codec
draft-ietf-codec-opus-update-06 draft-ietf-codec-opus-update-07
Abstract Abstract
This document addresses minor issues that were found in the This document addresses minor issues that were found in the
specification of the Opus audio codec in RFC 6716 [RFC6716]. specification of the Opus audio codec in RFC 6716.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 21, 2017. This Internet-Draft will expire on January 17, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 12 skipping to change at page 2, line 12
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Stereo State Reset in SILK . . . . . . . . . . . . . . . . . 3 3. Stereo State Reset in SILK . . . . . . . . . . . . . . . . . 3
4. Parsing of the Opus Packet Padding . . . . . . . . . . . . . 3 4. Parsing of the Opus Packet Padding . . . . . . . . . . . . . 3
5. Resampler buffer . . . . . . . . . . . . . . . . . . . . . . 4 5. Resampler buffer . . . . . . . . . . . . . . . . . . . . . . 4
6. Integer wrap-around in inverse gain computation . . . . . . . 5 6. Integer wrap-around in inverse gain computation . . . . . . . 6
7. Integer wrap-around in LSF decoding . . . . . . . . . . . . . 6 7. Integer wrap-around in LSF decoding . . . . . . . . . . . . . 6
8. Cap on Band Energy . . . . . . . . . . . . . . . . . . . . . 6 8. Cap on Band Energy . . . . . . . . . . . . . . . . . . . . . 7
9. Hybrid Folding . . . . . . . . . . . . . . . . . . . . . . . 7 9. Hybrid Folding . . . . . . . . . . . . . . . . . . . . . . . 7
10. Downmix to Mono . . . . . . . . . . . . . . . . . . . . . . . 9 10. Downmix to Mono . . . . . . . . . . . . . . . . . . . . . . . 9
11. New Test Vectors . . . . . . . . . . . . . . . . . . . . . . 9 11. New Test Vectors . . . . . . . . . . . . . . . . . . . . . . 9
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 12. Security Considerations . . . . . . . . . . . . . . . . . . . 9
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
15. Normative References . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction 1. Introduction
This document addresses minor issues that were discovered in the This document addresses minor issues that were discovered in the
reference implementation of the Opus codec that serves as the reference implementation of the Opus codec that serves as the
specification in RFC 6716 [RFC6716]. Only issues affecting the specification in RFC 6716 [RFC6716]. Only issues affecting the
decoder are listed here. An up-to-date implementation of the Opus decoder are listed here. An up-to-date implementation of the Opus
encoder can be found at https://opus-codec.org/. encoder can be found at <https://opus-codec.org/>.
Some of the changes in this document update normative behaviour in a Some of the changes in this document update normative behaviour in a
way that requires new test vectors. The English text of the way that requires new test vectors. The English text of the
specification is unaffected, only the C implementation is. The specification is unaffected, only the C implementation is. The
updated specification remains fully compatible with the original updated specification remains fully compatible with the original
specification. specification.
Note: due to RFC formatting conventions, lines exceeding the column Note: due to RFC formatting conventions, lines exceeding the column
width in the patch are split using a backslash character. The width in the patch are split using a backslash character. The
backslashes at the end of a line and the white space at the beginning backslashes at the end of a line and the white space at the beginning
of the following line are not part of the patch. A properly of the following line are not part of the patch. A properly
formatted patch including all changes is available at formatted patch including all changes is available at
<https://jmvalin.ca/misc_stuff/opus_update.patch>. (EDITOR: change <https://www.ietf.org/proceedings/98/slides/materials-98-codec-opus-
to an ietf.org link when ready) update-00.patch>.
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
3. Stereo State Reset in SILK 3. Stereo State Reset in SILK
The reference implementation does not reinitialize the stereo state The reference implementation does not reinitialize the stereo state
during a mode switch. The old stereo memory can produce a brief during a mode switch. The old stereo memory can produce a brief
impulse (i.e. single sample) in the decoded audio. This can be fixed impulse (i.e. single sample) in the decoded audio. This can be fixed
by changing silk/dec_API.c at line 72: by changing silk/dec_API.c at line 72:
<CODE BEGINS>
for( n = 0; n < DECODER_NUM_CHANNELS; n++ ) { for( n = 0; n < DECODER_NUM_CHANNELS; n++ ) {
ret = silk_init_decoder( &channel_state[ n ] ); ret = silk_init_decoder( &channel_state[ n ] );
} }
+ silk_memset(&((silk_decoder *)decState)->sStereo, 0, + silk_memset(&((silk_decoder *)decState)->sStereo, 0,
+ sizeof(((silk_decoder *)decState)->sStereo)); + sizeof(((silk_decoder *)decState)->sStereo));
+ /* Not strictly needed, but it's cleaner that way */ + /* Not strictly needed, but it's cleaner that way */
+ ((silk_decoder *)decState)->prev_decode_only_middle = 0; + ((silk_decoder *)decState)->prev_decode_only_middle = 0;
return ret; return ret;
} }
<CODE ENDS>
This change affects the normative part of the decoder, although the This change affects the normative part of the decoder, although the
amount of change is too small to make a significant impact on amount of change is too small to make a significant impact on
testvectors. testvectors.
4. Parsing of the Opus Packet Padding 4. Parsing of the Opus Packet Padding
It was discovered that some invalid packets of very large size could It was discovered that some invalid packets of very large size could
trigger an out-of-bounds read in the Opus packet parsing code trigger an out-of-bounds read in the Opus packet parsing code
responsible for padding. This is due to an integer overflow if the responsible for padding. This is due to an integer overflow if the
signaled padding exceeds 2^31-1 bytes (the actual packet may be signaled padding exceeds 2^31-1 bytes (the actual packet may be
smaller). The code can be fixed by applying the following changes at smaller). The code can be fixed by applying the following changes at
line 596 of src/opus_decoder.c: line 596 of src/opus_decoder.c:
<CODE BEGINS>
/* Padding flag is bit 6 */ /* Padding flag is bit 6 */
if (ch&0x40) if (ch&0x40)
{ {
- int padding=0; - int padding=0;
int p; int p;
do { do {
if (len<=0) if (len<=0)
return OPUS_INVALID_PACKET; return OPUS_INVALID_PACKET;
p = *data++; p = *data++;
len--; len--;
- padding += p==255 ? 254: p; - padding += p==255 ? 254: p;
+ len -= p==255 ? 254: p; + len -= p==255 ? 254: p;
} while (p==255); } while (p==255);
- len -= padding; - len -= padding;
} }
<CODE ENDS>
This packet parsing issue is limited to reading memory up to about 60 This packet parsing issue is limited to reading memory up to about 60
kB beyond the compressed buffer. This can only be triggered by a kB beyond the compressed buffer. This can only be triggered by a
compressed packet more than about 16 MB long, so it's not a problem compressed packet more than about 16 MB long, so it's not a problem
for RTP. In theory, it _could_ crash a file decoder (e.g. Opus in for RTP. In theory, it _could_ crash a file decoder (e.g. Opus in
Ogg) if the memory just after the incoming packet is out-of-range, Ogg) if the memory just after the incoming packet is out-of-range,
but our attempts to trigger such a crash in a production application but our attempts to trigger such a crash in a production application
built using an affected version of the Opus decoder failed. built using an affected version of the Opus decoder failed.
5. Resampler buffer 5. Resampler buffer
skipping to change at page 4, line 39 skipping to change at page 5, line 8
The fact that the code never produced any error in testing (including The fact that the code never produced any error in testing (including
when run under the Valgrind memory debugger), suggests that in when run under the Valgrind memory debugger), suggests that in
practice the batch sizes are reasonable enough that none of the practice the batch sizes are reasonable enough that none of the
issues above was ever a problem. However, proving that is non- issues above was ever a problem. However, proving that is non-
obvious. obvious.
The code can be fixed by applying the following changes to line 78 of The code can be fixed by applying the following changes to line 78 of
silk/resampler_private_IIR_FIR.c: silk/resampler_private_IIR_FIR.c:
<CODE BEGINS>
) )
{ {
silk_resampler_state_struct *S = \ silk_resampler_state_struct *S = \
(silk_resampler_state_struct *)SS; (silk_resampler_state_struct *)SS;
opus_int32 nSamplesIn; opus_int32 nSamplesIn;
opus_int32 max_index_Q16, index_increment_Q16; opus_int32 max_index_Q16, index_increment_Q16;
- opus_int16 buf[ RESAMPLER_MAX_BATCH_SIZE_IN + \ - opus_int16 buf[ RESAMPLER_MAX_BATCH_SIZE_IN + \
RESAMPLER_ORDER_FIR_12 ]; RESAMPLER_ORDER_FIR_12 ];
+ opus_int16 buf[ 2*RESAMPLER_MAX_BATCH_SIZE_IN + \ + opus_int16 buf[ 2*RESAMPLER_MAX_BATCH_SIZE_IN + \
RESAMPLER_ORDER_FIR_12 ]; RESAMPLER_ORDER_FIR_12 ];
skipping to change at page 5, line 34 skipping to change at page 6, line 4
/* More iterations to do; copy last part of \ /* More iterations to do; copy last part of \
filtered signal to beginning of buffer */ filtered signal to beginning of buffer */
- silk_memcpy( buf, &buf[ nSamplesIn << 1 ], \ - silk_memcpy( buf, &buf[ nSamplesIn << 1 ], \
RESAMPLER_ORDER_FIR_12 * sizeof( opus_int32 ) ); RESAMPLER_ORDER_FIR_12 * sizeof( opus_int32 ) );
+ silk_memmove( buf, &buf[ nSamplesIn << 1 ], \ + silk_memmove( buf, &buf[ nSamplesIn << 1 ], \
RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) ); RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) );
} else { } else {
break; break;
} }
} }
/* Copy last part of filtered signal to the state for \ /* Copy last part of filtered signal to the state for \
the next call */ the next call */
- silk_memcpy( S->sFIR, &buf[ nSamplesIn << 1 ], \ - silk_memcpy( S->sFIR, &buf[ nSamplesIn << 1 ], \
RESAMPLER_ORDER_FIR_12 * sizeof( opus_int32 ) ); RESAMPLER_ORDER_FIR_12 * sizeof( opus_int32 ) );
+ silk_memcpy( S->sFIR, &buf[ nSamplesIn << 1 ], \ + silk_memcpy( S->sFIR, &buf[ nSamplesIn << 1 ], \
RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) ); RESAMPLER_ORDER_FIR_12 * sizeof( opus_int16 ) );
} }
<CODE ENDS>
6. Integer wrap-around in inverse gain computation 6. Integer wrap-around in inverse gain computation
It was discovered through decoder fuzzing that some bitstreams could It was discovered through decoder fuzzing that some bitstreams could
produce integer values exceeding 32-bits in produce integer values exceeding 32-bits in
LPC_inverse_pred_gain_QA(), causing a wrap-around. Although the LPC_inverse_pred_gain_QA(), causing a wrap-around. Although the
error is harmless in practice, the C standard considers the behavior error is harmless in practice, the C standard considers the behavior
as undefined, so the following patch to line 87 of silk/ as undefined, so the following patch to line 87 of silk/
LPC_inv_pred_gain.c detects values that do not fit in a 32-bit LPC_inv_pred_gain.c detects values that do not fit in a 32-bit
integer and considers the corresponding filters unstable: integer and considers the corresponding filters unstable:
<CODE BEGINS>
/* Update AR coefficient */ /* Update AR coefficient */
for( n = 0; n < k; n++ ) { for( n = 0; n < k; n++ ) {
- tmp_QA = Aold_QA[ n ] - MUL32_FRAC_Q( \ - tmp_QA = Aold_QA[ n ] - MUL32_FRAC_Q( \
Aold_QA[ k - n - 1 ], rc_Q31, 31 ); Aold_QA[ k - n - 1 ], rc_Q31, 31 );
- Anew_QA[ n ] = MUL32_FRAC_Q( tmp_QA, rc_mult2 , mult2Q ); - Anew_QA[ n ] = MUL32_FRAC_Q( tmp_QA, rc_mult2 , mult2Q );
+ opus_int64 tmp64; + opus_int64 tmp64;
+ tmp_QA = silk_SUB_SAT32( Aold_QA[ n ], MUL32_FRAC_Q( \ + tmp_QA = silk_SUB_SAT32( Aold_QA[ n ], MUL32_FRAC_Q( \
Aold_QA[ k - n - 1 ], rc_Q31, 31 ) ); Aold_QA[ k - n - 1 ], rc_Q31, 31 ) );
+ tmp64 = silk_RSHIFT_ROUND64( silk_SMULL( tmp_QA, \ + tmp64 = silk_RSHIFT_ROUND64( silk_SMULL( tmp_QA, \
rc_mult2 ), mult2Q); rc_mult2 ), mult2Q);
+ if( tmp64 > silk_int32_MAX || tmp64 < silk_int32_MIN ) { + if( tmp64 > silk_int32_MAX || tmp64 < silk_int32_MIN ) {
+ return 0; + return 0;
+ } + }
+ Anew_QA[ n ] = ( opus_int32 )tmp64; + Anew_QA[ n ] = ( opus_int32 )tmp64;
} }
<CODE ENDS>
7. Integer wrap-around in LSF decoding 7. Integer wrap-around in LSF decoding
It was discovered -- also from decoder fuzzing -- that an integer It was discovered -- also from decoder fuzzing -- that an integer
wrap-around could occur when decoding line spectral frequency wrap-around could occur when decoding line spectral frequency
coefficients from extreme bitstreams. The end result of the wrap- coefficients from extreme bitstreams. The end result of the wrap-
around is an illegal read access on the stack, which the authors do around is an illegal read access on the stack, which the authors do
not believe is exploitable but should nonetheless be fixed. The not believe is exploitable but should nonetheless be fixed. The
following patch to line 137 of silk/NLSF_stabilize.c prevents the following patch to line 137 of silk/NLSF_stabilize.c prevents the
problem: problem:
<CODE BEGINS>
/* Keep delta_min distance between the NLSFs */ /* Keep delta_min distance between the NLSFs */
for( i = 1; i < L; i++ ) for( i = 1; i < L; i++ )
- NLSF_Q15[i] = silk_max_int( NLSF_Q15[i], \ - NLSF_Q15[i] = silk_max_int( NLSF_Q15[i], \
NLSF_Q15[i-1] + NDeltaMin_Q15[i] ); NLSF_Q15[i-1] + NDeltaMin_Q15[i] );
+ NLSF_Q15[i] = silk_max_int( NLSF_Q15[i], \ + NLSF_Q15[i] = silk_max_int( NLSF_Q15[i], \
silk_ADD_SAT16( NLSF_Q15[i-1], NDeltaMin_Q15[i] ) ); silk_ADD_SAT16( NLSF_Q15[i-1], NDeltaMin_Q15[i] ) );
/* Last NLSF should be no higher than 1 - NDeltaMin[L] */ /* Last NLSF should be no higher than 1 - NDeltaMin[L] */
<CODE ENDS>
8. Cap on Band Energy 8. Cap on Band Energy
On extreme bit-streams, it is possible for log-domain band energy On extreme bit-streams, it is possible for log-domain band energy
levels to exceed the maximum single-precision floating point value levels to exceed the maximum single-precision floating point value
once converted to a linear scale. This would later cause the decoded once converted to a linear scale. This would later cause the decoded
values to be NaN, possibly causing problems in the software using the values to be NaN, possibly causing problems in the software using the
PCM values. This can be avoided with the following patch to line 552 PCM values. This can be avoided with the following patch to line 552
of celt/quant_bands.c: of celt/quant_bands.c:
<CODE BEGINS>
{ {
opus_val16 lg = ADD16(oldEBands[i+c*m->nbEBands], opus_val16 lg = ADD16(oldEBands[i+c*m->nbEBands],
SHL16((opus_val16)eMeans[i],6)); SHL16((opus_val16)eMeans[i],6));
+ lg = MIN32(QCONST32(32.f, 16), lg); + lg = MIN32(QCONST32(32.f, 16), lg);
eBands[i+c*m->nbEBands] = PSHR32(celt_exp2(lg),4); eBands[i+c*m->nbEBands] = PSHR32(celt_exp2(lg),4);
} }
for (;i<m->nbEBands;i++) for (;i<m->nbEBands;i++)
<CODE ENDS>
9. Hybrid Folding 9. Hybrid Folding
When encoding in hybrid mode at low bitrate, we sometimes only have When encoding in hybrid mode at low bitrate, we sometimes only have
enough bits to code a single CELT band (8 - 9.6 kHz). When that enough bits to code a single CELT band (8 - 9.6 kHz). When that
happens, the second band (CELT band 18, from 9.6 to 12 kHz) cannot happens, the second band (CELT band 18, from 9.6 to 12 kHz) cannot
use folding because it is wider than the amount already coded, and use folding because it is wider than the amount already coded, and
falls back to LCG noise. Because it can also happen on transients falls back to LCG noise. Because it can also happen on transients
(e.g. stops), it can cause audible pre-echo. (e.g. stops), it can cause audible pre-echo.
To address the issue, we change the folding behavior so that it is To address the issue, we change the folding behavior so that it is
never forced to fall back to LCG due to the first band not containing never forced to fall back to LCG due to the first band not containing
enough coefficients to fold onto the second band. This is achieved enough coefficients to fold onto the second band. This is achieved
by simply repeating part of the first band in the folding of the by simply repeating part of the first band in the folding of the
second band. This changes the code in celt/bands.c around line 1237: second band. This changes the code in celt/bands.c around line 1237:
<CODE BEGINS>
b = 0; b = 0;
} }
- if (resynth && M*eBands[i]-N >= M*eBands[start] && \ - if (resynth && M*eBands[i]-N >= M*eBands[start] && \
(update_lowband || lowband_offset==0)) (update_lowband || lowband_offset==0))
+ if (resynth && (M*eBands[i]-N >= M*eBands[start] || \ + if (resynth && (M*eBands[i]-N >= M*eBands[start] || \
i==start+1) && (update_lowband || lowband_offset==0)) i==start+1) && (update_lowband || lowband_offset==0))
lowband_offset = i; lowband_offset = i;
+ if (i == start+1) + if (i == start+1)
skipping to change at page 8, line 33 skipping to change at page 8, line 34
+ Copies no data for CELT-only mode. */ + Copies no data for CELT-only mode. */
+ OPUS_COPY(&norm[offset+n1], &norm[offset+2*n1 - n2], n2-n1); + OPUS_COPY(&norm[offset+n1], &norm[offset+2*n1 - n2], n2-n1);
+ if (C==2) + if (C==2)
+ OPUS_COPY(&norm2[offset+n1], &norm2[offset+2*n1 - n2], \ + OPUS_COPY(&norm2[offset+n1], &norm2[offset+2*n1 - n2], \
n2-n1); n2-n1);
+ } + }
+ +
tf_change = tf_res[i]; tf_change = tf_res[i];
if (i>=m->effEBands) if (i>=m->effEBands)
{ {
<CODE ENDS>
as well as line 1260: as well as line 1260:
<CODE BEGINS>
fold_start = lowband_offset; fold_start = lowband_offset;
while(M*eBands[--fold_start] > effective_lowband); while(M*eBands[--fold_start] > effective_lowband);
fold_end = lowband_offset-1; fold_end = lowband_offset-1;
- while(M*eBands[++fold_end] < effective_lowband+N); - while(M*eBands[++fold_end] < effective_lowband+N);
+ while(++fold_end < i && M*eBands[fold_end] < \ + while(++fold_end < i && M*eBands[fold_end] < \
effective_lowband+N); effective_lowband+N);
x_cm = y_cm = 0; x_cm = y_cm = 0;
fold_i = fold_start; do { fold_i = fold_start; do {
x_cm |= collapse_masks[fold_i*C+0]; x_cm |= collapse_masks[fold_i*C+0];
<CODE ENDS>
The fix does not impact compatibility, because the improvement does The fix does not impact compatibility, because the improvement does
not depend on the encoder doing anything special. There is also no not depend on the encoder doing anything special. There is also no
reasonable way for an encoder to use the original behavior to improve reasonable way for an encoder to use the original behavior to improve
quality over the proposed change. quality over the proposed change.
10. Downmix to Mono 10. Downmix to Mono
The last issue is not strictly a bug, but it is an issue that has The last issue is not strictly a bug, but it is an issue that has
been reported when downmixing an Opus decoded stream to mono, whether been reported when downmixing an Opus decoded stream to mono, whether
this is done inside the decoder or as a post-processing step on the this is done inside the decoder or as a post-processing step on the
skipping to change at page 9, line 37 skipping to change at page 9, line 39
do not apply the CELT 180-degree phase shift as allowed in do not apply the CELT 180-degree phase shift as allowed in
Section 10, while the outputs without the suffix do. An Section 10, while the outputs without the suffix do. An
implementation is compliant as long as it passes either set of implementation is compliant as long as it passes either set of
vectors. vectors.
In addition, any Opus implementation that passes the original test In addition, any Opus implementation that passes the original test
vectors from RFC 6716 [RFC6716] is still compliant with the Opus vectors from RFC 6716 [RFC6716] is still compliant with the Opus
specification. However, newer implementations SHOULD be based on the specification. However, newer implementations SHOULD be based on the
new test vectors rather than the old ones. new test vectors rather than the old ones.
The new test vectors are located at <https://jmvalin.ca/misc_stuff/ The new test vectors are located at
opus_newvectors.tar.gz>. (EDITOR: change to an ietf.org link when <https://www.ietf.org/proceedings/98/slides/materials-98-codec-opus-
ready) newvectors-00.tar.gz>.
12. IANA Considerations 12. Security Considerations
This document adds no new security considerations on top of RFC 6716
[RFC6716].
13. IANA Considerations
This document makes no request of IANA. This document makes no request of IANA.
Note to RFC Editor: this section may be removed on publication as an Note to RFC Editor: this section may be removed on publication as an
RFC. RFC.
13. Acknowledgements 14. Acknowledgements
We would like to thank Juri Aedla for reporting the issue with the We would like to thank Juri Aedla for reporting the issue with the
parsing of the Opus padding. Also, thanks to Jonathan Lennox and parsing of the Opus padding. Also, thanks to Jonathan Lennox and
Mark Harris for their feedback on this document. Mark Harris for their feedback on this document.
14. References 15. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the [RFC6716] Valin, JM., Vos, K., and T. Terriberry, "Definition of the
Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716, Opus Audio Codec", RFC 6716, DOI 10.17487/RFC6716,
September 2012, <http://www.rfc-editor.org/info/rfc6716>. September 2012, <http://www.rfc-editor.org/info/rfc6716>.
 End of changes. 30 change blocks. 
21 lines changed or deleted 43 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/