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1. #How to get 5.1 aac sound in xmedia recode full#
2. #How to get 5.1 aac sound in xmedia recode portable#
3. #How to get 5.1 aac sound in xmedia recode software#
4. #How to get 5.1 aac sound in xmedia recode code#

#How to get 5.1 aac sound in xmedia recode full#

The end result is an apparent full bandwidth transmission (as if no low-pass filter was applied), even though the actual AAC-LC encoded audio is only storing frequencies up to 1/4 the original sample rate. The HE-AAC and HE-AACv2 profiles encode audio using AAC-LC at one half the sample rate, relying on Spectral Band Replication (SBR) to attempt reconstruction of the missing higher frequencies. More information can be found in the official documentation, section 3.1 Bandwidth.

The fdk-aac parameter is AACENC_BANDWIDTH. This can be overridden, but the maximum value is 20000 Hz. The default bandwidth (or low-pass filter cutoff) for each bitrate mode will be the minimum of the appropriate value in the tables below or half the sample rate. HE and HEv2 will often end up with actual bitrates far below these limits.Ī Note that a "stereo" channel is any that is bonded with another channel, as noted with a plus sign in the channel layouts table.ġ "mono" center channel at 56 kbps and 2 "stereo" channels at 48kbps = 152kbpsġ "mono" center channel and 1 mono LFE channel each at 72kbps, and 4 "stereo" channels (2 sets of 2) each at 64kbps = 400kbpsĪ spectrogram showing the effect of the FDK AAC low-pass filter. The bitrate limit for each variable bitrate mode. LD/ELD full bitreservoir for packet based transmission "Low Delay Profile" used for real-time communicationĬalculated based on channel layout (See table below) "AAC Profile" MPEG-2 Low-complexity (LC) combined with MPEG-4 Perceptual Noise Substitution (PNS) The library supports the following MPEG-2/4 AOTs: : Fedora has since adopted a more defensive posture to patent language, making it not AllowedĪfterburner is "a type of analysis by synthesis algorithm which increases the audio quality but also the required processing power." Fraunhofer recommends to always activate this feature. (The AAC patent license covers both encoder and decoder, so using fdk_aac does not add patent violations to FFmpeg.) The position of FFmpeg is that although the license is GPL-incompatible (and therefore nondistributable with GPL parts), it is acceptable to distribute the library with LGPL parts. Debian does not comment on the patent situation.

#How to get 5.1 aac sound in xmedia recode software#

This license puts a limitation on charging for software that includes the library, leading Debian to consider it non-free. Considering the patent terms, all AAC software are indeed equally affected. The Free Software Foundation (FSF) considers it fishy to have an invitation to purchase patent licenses in the text, but concedes that "any program is potentially threatened by patents". As this governs use, it should not have anything to do with distribution.

It goes on to say "you may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized by appropriate patent licenses".

#How to get 5.1 aac sound in xmedia recode code#

The license included by Fraunhofer in the FDK source code specifically allows distribution in source or binary forms, but does not license patented technologies described by the source code. It is included in both projects, and is the recommended AAC encoder for FFmpeg. Includes libfdk-aac* and the aac-enc encoding front end.Īn advanced front-end to the FDK AAC encoder using libfdk-aac.Ī wrapper for libfdk-aac that adds support to FFmpeg and Libav/avconv. Libfdk-aac0 (shared library version 1.1.0)

#How to get 5.1 aac sound in xmedia recode portable#

The FDK AAC encoder and decoder as a portable library separate from Android.