HTML5 AAC Audio Playback Tests - Experimental
Fraunhofer Institute for Integrated Circuits
Resampling Tests
20 Hz - 20 kHz sweep, 20 seconds, 48 kHz sampling rate, AOT = 5, explicit signalling, backwards compatible
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20 Hz - 20 kHz sweep, 20 seconds, 48 kHz sampling rate, AOT = 2
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Original Wave File
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Clipping Test
This signal tests the ability of a decoder to handle overshoots above full scale limits in the bitstream, such as will be produced by encoding highly compressed, hard limited or clipped ultra-hot CDs, particularly with "0 dBFS +" mastering.
On a decoder or player with a safety limiter or unsaturated floating point output, you should hear a pure tone that increases in loudness (with a brief transient when the level changes every two seconds). On a simple decoder (as on mobile devices) you will hear clipping until it becomes so strong the waveform just becomes a square wave and you hear additional harmonics.
999 Hz sine wave, -2 dB FS (undistorted reference), 0, +1 ,2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 dbFS. 2 seconds each step. AAC-LC stereo, 44.1 kHz, 128 kb/s.
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Input signal to specially modified encoder. This signal is 12 dB lower than the bitstream values produced by the modifed encoder. The bitstream will make a reconstructed signal in a standard decoder that is 12 dB higher.
Original Wave File
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Output of simple decoder with no clipping protection:
Original Wave File
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High Bitrate HE-AAC Test
This signal tests for proper support of the high bitrate HE-AAC mode for extended audio quality.
Stereo HE-AAC SBR Check and Channel ID, 96 kb/s
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5. 1 Channel LFE and SBR Test, 320 kb/s
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