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| author | Jean-Michel Trivi <jmtrivi@google.com> | 2013-08-29 15:17:49 -0700 |
|---|---|---|
| committer | Jean-Michel Trivi <jmtrivi@google.com> | 2013-09-03 11:44:33 -0700 |
| commit | 9f455bea1c38f7275a65ab79be2d41a34428fb8b (patch) | |
| tree | 7421f0722c4970d0b463ebcc8499dd6e8652f48a /libAACenc/include/aacenc_lib.h | |
| parent | dbf96806482b2c48de4ba1da9a03e2bb7516b8c2 (diff) | |
| download | fdk-aac-9f455bea1c38f7275a65ab79be2d41a34428fb8b.tar.gz fdk-aac-9f455bea1c38f7275a65ab79be2d41a34428fb8b.tar.bz2 fdk-aac-9f455bea1c38f7275a65ab79be2d41a34428fb8b.zip | |
Encoder ELD auto configurator
* 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
Diffstat (limited to 'libAACenc/include/aacenc_lib.h')
| -rw-r--r-- | libAACenc/include/aacenc_lib.h | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/libAACenc/include/aacenc_lib.h b/libAACenc/include/aacenc_lib.h index fcdaca5..f693bf5 100644 --- a/libAACenc/include/aacenc_lib.h +++ b/libAACenc/include/aacenc_lib.h @@ -342,6 +342,33 @@ increase which might be significant. If workload is not an issue in the applicat we recommended to activate this feature. \code aacEncoder_SetParam(hAacEncoder, AACENC_AFTERBURNER, 1); \endcode +\subsection encELD ELD Auto Configuration Mode +For ELD configuration a so called auto configurator is available which configures SBR and the SBR ratio by itself. +The configurator is used when the encoder parameter ::AACENC_SBR_MODE and ::AACENC_SBR_RATIO are not set explicitely. + +Based on sampling rate and chosen bitrate per channel a reasonable SBR configuration will be used. +\verbatim +------------------------------------------------------------ + Sampling Rate | Channel Bitrate | SBR | SBR Ratio +-----------------+-----------------+------+----------------- + ]min, 16] kHz | min - 27999 | on | downsampled SBR + | 28000 - max | off | --- +-----------------+-----------------+------+----------------- + ]16 - 24] kHz | min - 39999 | on | downsampled SBR + | 40000 - max | off | --- +-----------------+-----------------+------+----------------- + ]24 - 32] kHz | min - 27999 | on | dualrate SBR + | 28000 - 55999 | on | downsampled SBR + | 56000 - max | off | --- +-----------------+-----------------+------+----------------- + ]32 - 44.1] kHz | min - 63999 | on | dualrate SBR + | 64000 - max | off | --- +-----------------+-----------------+------+----------------- + ]44.1 - 48] kHz | min - 63999 | on | dualrate SBR + | 64000 - max | off | --- +------------------------------------------------------------ +\endverbatim + \section audiochCfg Audio Channel Configuration The MPEG standard refers often to the so-called Channel Configuration. This Channel Configuration is used for a fixed Channel @@ -881,8 +908,9 @@ typedef enum AACENC_SAMPLERATE = 0x0103, /*!< Audio input data sampling rate. Encoder supports following sampling rates: 8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000, 64000, 88200, 96000 */ - AACENC_SBR_MODE = 0x0104, /*!< Configure SBR independently of the chosen Audio Object Type ::AUDIO_OBJECT_TYPE:. - This parameter is only available for ELD. + AACENC_SBR_MODE = 0x0104, /*!< Configure SBR independently of the chosen Audio Object Type ::AUDIO_OBJECT_TYPE. + This parameter is for ELD audio object type only. + - -1: Use ELD SBR auto configurator (default). - 0: Disable Spectral Band Replication. - 1: Enable Spectral Band Replication. */ |