Operating the FDK encoder in A2DP with variable bitrate mode
configuration resulted in unexpected encoder return value AACENC_ENCODE_ERROR.
Due to peak bitrate restriction the encoder quite often runs into requantization.
In case the bitrate constraint is not fulfilled, the so-called crash recovery is
used as final emergency step. The crash recovery reduces the overall bit
consumption considering the given number of bits to be saved. The bit difference
is extracted from audio element structures. In VBR mode the element wise bit
consumption state was not updated since there is typically no bitrate limitation
required.
The patch solves the choppy audio problems and increases audio quality for
AAC VBR encoding.
The changes in FDKaacEnc_QCMain() ensure that audio element bit info is always
updated. This is achieved by always calling FDKaacEnc_BitResRedistribution()
and FDKaacEnc_prepareBitDistribution() with maxBitsPerFrame variable as total
bits parameter.
Furthermore, VBR assumes a certain target bitrate which is used for internal
configuration and limitations. In case the peak bitrate parameter is less than
the VBR mode target bitrate the maximum of both bitrate configurations was used.
The function FDKaacEnc_AdjustVBRBitrateMode() is added to adjust the encoder
internal VBR mode to a desired target bitrate less than given peak bitrate.
It is possible that the peak bitrate is very close to the desired target bitrate.
The virtual available bitreservoir is quite low and the encoder would run quite
often into requantization with needless audio quality reduction. In such a
configuration, it is a better choice to use the CBR targeted threshold adaption
to avoid audio quality reduction.
In FDKaacEnc_Initialize(), there was already a bitResMode selection depending
on available bitreservoir for CBR. This selection will now also be used for VBR.
In case the bitResMode is AACENC_BR_MODE_FULL and VBR mode is selected, the VBR
threshold adaption is used. Otherwise, CBR threshold adaption strategy is used
and therefore, no unnecessary fill bits are written.
Bug: 161400526
Test: see bug
Change-Id: I1865f817180150da6add2623a64f1a102622784a
1) Fixes some potential NULL-pointer access in case input pointer is
passed NULL
2) Modified some for lazy init
Test: mm -j 8
Change-Id: I7fca97e1d9f70d8e8c1533b519181af35a5468f7
am: 2b2e97b
* commit '2b2e97b893b16b69c7728d16e8653b9c94944294':
Left shift of negative int is undefined
Change-Id: Ie90b850b7adf787dfb47f8b7c43a22744c3a7fa0
Building __DATE__/__TIME__ into the binaries means that every build will
create different binaries, even if all the sources are identical. This
also means that any libraries including this one will need to be patched
during every OTA.
Nothing appears to use the build_date/build_time fields, so just replace
them with empty strings.
Bug: 24204119
Change-Id: I9543eb388a1e8ab9284df9035a62fc8942cdc082
* AAC-Encoder
- Introduce ELD auto configurator to get predefined configuration at given
bitrate and sampling rate. The configurator selects SBR on/off and if SBR
enabled distinguishes between dualrate and downsampled SBR. In default
configuration the ELD auto configurator is enabled.
Modified file(s):
libAACenc\include\aacenc_lib.h
libAACenc\src\aacenc_lib.cpp
Bug 9428126
Change-Id: I01acc9c37e57c4154b3a818d496d538b7f8b227d
* AAC-Encoder
- Revise explicit signaling method which is required for downsampled SBR.
The parameter is optional and default configuration is implicit signaling
for dualrate SBR as before. In case of downsampled SBR and HE-AAC explicit
signaling is configured as default.
Modified file(s):
documentation\aacEncoder.pdf
libAACenc\include\aacenc_lib.h
libAACenc\src\aacenc_lib.cpp
libMpegTPEnc\src\tpenc_asc.cpp
libMpegTPEnc\src\version
libSYS\include\FDK_audio.h
libSYS\src\genericStds.cpp
Bug 9428126
Change-Id: I35138140346f17384d109ee5829be9ea5bab80fc
AAC encoder: Connect SBR and PS header repetition rate with AACENC_HEADER_PERIOD
parameter of the encoder API.
Bug 9428126
Change-Id: Ia1ab965de9eaa2ac229d0c395a337cbd4d20cba1
AAC encoder: Make the bit rate limiting functionality more stable for multichannel
configurations where element bit rate for SBR can differ significantly.
Bug 9428126
Change-Id: I35b134c5b3c160a8f5a16b4314782b731fe49cd8
SBR encoder: Introduce coupling energy ratio limitation to prevent undesirable SBR band
amplification while decoding.
Bug 9428126
Change-Id: I18a77cd1a178fff7531b490779a29a0df7d993af
AAC Encoder: Saturate quantizer shift value to prevent
undefined behaviour.
In very rare cases the shift value 'totalShift = (16-4)-(3*(totalShift>>2))'
can be greater than accu data width. If you apply a shift with more then
31 bit the result depends on the architecture and is not defined in C.
For certain platforms zeros are shifted in. That would be our desired behaviour.
On other platforms the shift will be applied as modulo. For example >>34
would be applied as >>2. To prevent this discrepancy the shift value
is limited/saturated to DFRACT_BITS-1. 'accu >>= fixMin(totalShift,DFRACT_BITS-1)'.
Bug 9428126
Change-Id: I27177654c4dc22cf899bc35dad9cdd040dccb02d
* AAC-Encoder
- Remove source snippets related to unsupported frame length of 960.
- Adjust minBits initialization for disabled VBR configuration.
Modified file(s):
libAACenc/src/aacenc.h
libAACenc/src/aacenc_lib.cpp
libAACenc/src/aacenc_tns.cpp
libAACenc/src/bandwidth.cpp
libAACenc/src/psy_const.h
libAACenc/src/transform.h
- Revise encoder parameter restrictions: "Error Resilient(ER) AAC Low Complexity"
is not supported. Where the AAC part of the FDK encoder threw an
initialization error, now the aacEncoder_SetParam() returns an error
before initialization if the application tries to configure this
audio object type.
Modified file(s):
libAACenc/src/aacenc_lib.cpp
* SYS-Library
- Portability fix for Mingw32.
Modified file(s):
libSYS/include/machine_type.h
- Minor changes.
Modified file(s):
libSYS/include/wav_file.h
libSYS/src/wav_file.cpp
libSYS/src/cmdl_parser.cpp
libSYS/src/genericStds.cpp
Bug 9428126
Change-Id: I9fa44923d34f033d0dc607f2b85abacb8a85eb61
- Update disclaimer in all source files.
- Increment library version in each FDK sub-module.
Bug 9428126
Change-Id: I490b96d4ee472246b01483202b0bb4f1e9c2a5d7
From Fraunhofer:
* AAC Decoder
- Stick to the written MPEG standard instead of the MPEG reference software
in terms of reference level normalization. Always set the program reference
level equal to the target level. This disables level normalization using a
default level for streams without embedded metadata.
Modified file(s):
libAACdec\src\aacdec_drc.cpp
- Fix downmix channel assignment when using a WAV output channel ordering.
Modified file(s):
libPCMutils\src\pcmutils_lib.cpp
- Retain signal accuracy and prevent LSB alteration when no level correction
needs to be done.
Modified file(s):
libAACdec\src\aacdec_drc.h
libAACdec\src\aacdec_drc.cpp
libSBRdec\src\sbrdecoder.cpp
libSBRdec\src\sbr_dec.cpp
libSBRdec\src\sbrdec_drc.cpp
- Align metadata processing with reference implementation.
Modified file(s):
libAACdec\src\aacdec_drc.h
libAACdec\src\aacdecoder.cpp
* AAC-Encoder
- Prevent potential overflow in energy calculation after TNS processing.
Modified file(s):
libAACenc\src\band_nrg.cpp
- Added saturation for number of relevant lines which are used in pe
calculation.
Modified file(s):
libAACenc\src\line_pe.cpp
- Removed obsolete files.
Deleded file(s):
libAACenc\src\tns_param.h
libAACenc\src\tns_param.cpp
* FDK-Library
- Added x86 Count Leading Zeros intrinsic.
Modified file(s):
libFDK\include\clz.h
Added file(s):
libFDK\include\x86\clz_x86.h
- Fixed compilation for MIPS GCC-4.4 and higher.
Modified file(s):
libFDK\include\mips\cplx_mul.h
libFDK\include\mips\fixmul_mips.h
Change-Id: I4be65f07f88d412224c7fddc3f054e8f451176cc
Latest code drop from Fraunhofer:
* AAC-Decoder
- Expanded AAC-LD/ELD decoder TNS max band tables to avoid wrong data
access for sampling rates <22kHz and >48kHz.
Modified file(s):
libAACdec\src\aacdec_tns.cpp
libAACdec\src\aac_rom.h
libAACdec\src\aac_rom.cpp
- Fixed ELD synthesis QMF filterbank scaling for downsampled SBR.
Modified file(s):
libFDK\src\qmf.cpp
* AAC-Encoder
- Fixed bit rate limiting for lower limit as introduced in the Delivery 2012-05-11.
Modified file(s):
libAACenc\include\aacenc_lib.h
libAACenc\src\aacenc.h
libAACenc\src\aacenc.cpp
libSBRenc\src\sbr_rom.h
libSBRenc\src\sbr_rom.cpp
- Allow negative prediction gain as meaning that there is no coding gain.
Make use of scaleValueSaturate in gauss window calculation.
Modified file(s):
libAACenc\src\aacenc_tns.cpp
- Added energy saturation to prevent overflow in short blocks.
Modified file(s):
libAACenc\src\grp_data.cpp
- Perform scalefactor adaption in case quantized lines are out of valid range.
Modified file(s):
libAACenc\src\quantize.cpp
- Interrupt quantization loop when no spectral data is available.
Adjustments in bitreservoir adaption.
Modified file(s):
libAACenc\src\qc_main.cpp
- Indroduced dynamic scaling in none missing harmonic energy lowering compensation.
Modified file(s):
libSBRenc\src\env_est.cpp
* FDK-Library
- Fixed saturation for negative values in scaleValueSaturate.
Modified file(s):
libFDK\include\scale.h
Change-Id: If830ea65caef6b5554281e4b7a77a8b2e08825ce
Shifting by more than (or equal to) the variable length is
undefined in C.
This caused the quantized spectrum values to go out of range,
triggering asserts later.
Change-Id: If81b6c8caa7b9c75941ad9d280b686d2069c968c
Fraunhofer IIS FDK
Kris Alder
Anuj Joshi
liuchao
Glenn Kasten
Glenn Kasten
Jean-Michel Trivi
Dan Willemsen
Martin Storsjo
The Android Open Source Project