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List Info
Thread: CR: Duration based Audio Error Concealment
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| CR: Duration based Audio Error
Concealment |
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2008-03-26 12:09:39 |
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| RE: CR: Duration based Audio Error
Concealment |
 
United States |
2008-03-26 13:08:27 |
Looks good.
=============================================
Eric Hyche (ehyche real.com)
Technical Lead
RealNetworks, Inc.
> -----Original Message-----
> From: datatype-dev-bounceshelixcommunity.org
> [mailto:datatype-dev-bounceshelixcommunity.org] On
Behalf Of
> ext-anuj.dhamijanokia.com
> Sent: Wednesday, March 26, 2008 1:10 PM
> To: nokia-private-dev-bounceshelixcommunity.org;
> datatype-devhelixcommunity.org
> Subject: [datatype-dev] CR: Duration based Audio Error
Concealment
>
> "Nokia submits this code under the
> terms of a commercial contribution agreement with
> RealNetworks, and I am authorized to contribute this
code
> under said agreement."
>
>
> Modified by: ext-anuj.dhamijanokia.com
>
> Reviewed by:
>
> Date: 03/24/2008
>
> Project: SymbianMmf_rel
>
> Synopsis: Change the Audio Error
> Concealment logic to be based on Duration instead of
Number
> of Packets
>
> Overview:
> Current Audio Error Concealment
> involves replicating prior (faded) audio packets for a
> predefined number of packets in case of packet drop.
Modify
> this to replicate packets for a predefined duration
rather
> than number of packets. This predefined duration is
defined
> as a parameter in configuration file. Its default value
is
> set to 20 milliseconds.
>
> Fix:
> Introduce new class members in
> HXSymbianSwAudioDecoder for Configured Error
Concealment
> Duration and Consecutive Loss Duration (Counter). Read
in the
> Configured value for Error Concealment from
configuration
> file when Decoder is opened. Every time packet drop
occurs
> increment Consecutive loss duration by the duration of
the
> frame and introduce the faded copy of last audio frame
> played. If Consecutive Loss Duration exceeds the
configured
> Error Concealment duration then insert silence.
>
> Reset the Consecutive Loss Duration to
> zero in Decode method which is invoked when packets are
> received without any error.
>
> New Field Added to configuration file:
> AudioErrorConcDuration
>
> Files modified & changes:
>
>
>
srcdatatypemp4audiomdfpubplatformsymbiansymbianswdec
oder.h
>
>
srcdatatypemp4audiomdfplatformsymbiansymbianswdecoder
.cpp
>
>
>
srcclientappssymbiancommonconfigR1_Mobile_4_0_Factory.cf
g
>
> Image Size and Heap Use impact: None
>
> Module Release testing (STIF, Audio) : Passed
>
> Test case(s) Added : No
>
> Memory leak check performed : Passed,
> No leaks found
>
> Platforms and Profiles Build Verified:
> helix-client-s60-32-mmf-mdf-arm
>
> Platforms and Profiles Functionality
> verified: armv5
>
> Branch: Head, 210CayS & 221CayS
>
>
> Index: symbianswdecoder.h
>
>
============================================================
=======
> RCS file:
>
/cvsroot/datatype/mp4/audio/mdf/pub/platform/symbian/symbian
sw
> decoder.h,v
> retrieving revision 1.1.2.1
> diff -u -w -r1.1.2.1 symbianswdecoder.h
> --- symbianswdecoder.h 3 Oct 2007
> 22:43:30 -0000 1.1.2.1
> +++ symbianswdecoder.h 24 Mar 2008
> 20:13:42 -0000
> -73,7 +73,8
> CMMFDataBuffer*
> m_pSourceBuffer;
> CMMFDataBuffer* m_pDestBuffer;
> HXBOOL
> m_bPrevBuffValid;
> - UINT32
> m_ulConsecutiveLossCount;
> + UINT32
> m_ulConsecutiveLossDuration;
> + UINT32
> m_ulErrorConcDuration;
> };
>
> #endif // __SYMBIAN_SW_DECODER_H__
>
> Index: symbianswdecoder.cpp
>
>
============================================================
=======
> RCS file:
>
/cvsroot/datatype/mp4/audio/mdf/platform/symbian/symbianswde
co
> der.cpp,v
> retrieving revision 1.2.2.3
> diff -u -w -r1.2.2.3 symbianswdecoder.cpp
> --- symbianswdecoder.cpp 3 Oct
> 2007 22:42:23 -0000 1.2.2.3
> +++ symbianswdecoder.cpp 24 Mar
> 2008 20:12:33 -0000
> -46,16 +46,15
> #include "symbianaudiodecoder.h"
> #include "symbianswdecoder.h"
>
> -// Came up with this value after
> considering the quality of audio
> -// Increasing the value of
> REPEAT_MAX_LIMIT creates noise
> -#define REPEAT_MAX_LIMIT 10
> +#include "hxprefutil.h"
>
>
> HXSymbianSwAudioDecoder::HXSymbianSwAudioDecoder():
> m_pSoftwareCodec(NULL), // set
> by OpenDecoder()
> m_pSourceBuffer(NULL), // set
> by OpenDecoder()
> m_pDestBuffer(NULL), // set
> by OpenDecoder()
> m_bPrevBuffValid(FALSE),
> - m_ulConsecutiveLossCount(0)
> + m_ulConsecutiveLossDuration(0),
> + m_ulErrorConcDuration(0)
> {
> }
>
> -141,8 +140,14
> {
> // perform codec specific configuration
> result =
> m_pAudConfig->ConfigureDecoder(m_pSoftwareCodec);
> + if(m_pContext)
> + {
> +
> if(HXR_OK!=ReadPrefUINT32(m_pContext,
> "AudioErrorConcDuration",
m_ulErrorConcDuration))
> + {
> +
> m_ulErrorConcDuration = 20;
> + }
> + }
> }
> -
> return result;
> }
>
> -251,7 +256,7
> nBytesConsumed =
> (UINT32) result.iSrcBytesProcessed;
> nSamplesOut =
> ConvertBytesToSamples(result.iDstBytesAdded);
> m_bPrevBuffValid = TRUE;
> - m_ulConsecutiveLossCount = 0;
> +
> m_ulConsecutiveLossDuration = 0;
> }
> }
> }
> -265,8 +270,11
> // causes to consume memory and performance
> void
> HXSymbianSwAudioDecoder::RepeatAndFadeRepair(INT16
> *samplesOut, UINT32 nSamplesOut)
> {
> - // Fade, if we have lost multiple
> consecutive frames upto REPEAT_MAX_LIMIT
> - if ( m_bPrevBuffValid && 0 <
> m_ulConsecutiveLossCount &&
m_ulConsecutiveLossCount <
> REPEAT_MAX_LIMIT )
> + // Fade, if we have lost multiple
> consecutive frames upto configiured Error Conc duration
> + if ( m_bPrevBuffValid &&
> + ( 0 < m_ulConsecutiveLossDuration )
&&
> + (m_ulConsecutiveLossDuration <
> m_ulErrorConcDuration)
> + )
> {
> double samples_per_frame =
> (double)m_pAudConfig->SamplesPerFrame();
> double fade_duration_in_frames
> = (double)m_pAudConfig->MillisPerFrame();
> -283,12 +291,12
> scale_factor -= fade_per_sample;
> }
> }
> - // Loss after REPEAT_MAX_LIMIT
> insert silence
> - else if ( !m_bPrevBuffValid ||
> m_ulConsecutiveLossCount >= REPEAT_MAX_LIMIT )
> + // Loss after Error Conc duration
> insert silence
> + else if ( !m_bPrevBuffValid ||
> m_ulConsecutiveLossDuration >=
m_ulErrorConcDuration)
> {
> memset(samplesOut, 0,
> nSamplesOut * sizeof(INT16));
> }
>
> - m_ulConsecutiveLossCount++;
> + m_ulConsecutiveLossDuration +=
> m_pAudConfig->MillisPerFrame();
> }
>
>
> Index: R1_Mobile_4_0_Factory.cfg
>
>
============================================================
=======
> RCS file:
>
/cvsroot/clientapps/symbiancommon/config/R1_Mobile_4_0_Facto
ry.cfg,v
> retrieving revision 1.26.2.22.2.1
> diff -u -w -r1.26.2.22.2.1
> R1_Mobile_4_0_Factory.cfg
> --- R1_Mobile_4_0_Factory.cfg 26 Feb
> 2008 21:53:58 -0000 1.26.2.22.2.1
> +++ R1_Mobile_4_0_Factory.cfg 24 Mar
> 2008 20:16:03 -0000
> -118,3 +118,7
> LANMaximumBandwidth=3000000
> LANSustainBandwidth=2100000
>
> +#Audio Error Concealment Duration
> (milliseconds)
> +#In case of packet drop interpolate
> Audio Packets for this duration
> +#defaults to 20 milliseconds
> +AudioErrorConcDuration=20
>
>
> ------------
> thnx & regds
> AD
>
>
>
>
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