HTML5 AAC Audio Playback Tests - MPEG-D DRC Metadata
Fraunhofer Institute for Integrated Circuits
General
This page tests if an xHE-AAC decoder correctly applies MPEG-D DRC audio-specific metadata, including program reference level, dynamic range control and downmixing. It consists of a number of xHE-AAC bitstreams, designed in a way that allows for a rough verification of these features by simply listening to the decoder output.
Note that this page does not test the legacy metadata introduced for use with AAC-LC and HE-AAC.
Test 1: Loudness Normalization Test
| Audio | Noise signal |
| Test | Two items which test whether the decoder applies loudness normalization according to ISO/IEC 23003-4. |
| Expected Output | If the decoder correctly applies loudness normalization, the two test items are reproduced at equal level. If the decoder does not apply loudness normalization, the two test items are reproduced at different levels. |
xHE-AAC
Download File
xHE-AAC
Download File
Reference decoder output - Generated with a decoder target loudness setting of -16 LKFS
Test 2: DRC Test
| Audio | Modulated sine wave |
| Test | This item tests whether the decoder applies dynamic range control according to ISO/IEC 23003-4. |
| Expected Output | If the decoder correctly applies dynamic range control, an unmodulated sine wave is reproduced. If the decoder does not apply dynamic range control, a modulated sine wave is reproduced. |
xHE-AAC
Download File
Special test version, signalled in HTML5 as AOT 2
Download File
Reference decoder output - Generated with a decoder target loudness setting of -16 LKFS and DRC processing enabled
Test 3: DRC Test 2
| Audio | 1 kHz sine wave |
| Test | This item tests whether the decoder applies DRC gain interpolation according to ISO/IEC 23003-4. |
| Expected Output | If the decoder correctly applies DRC gain interpolation, a 1 kHz sine wave with low-level modulated background noise is reproduced. If the decoder does not apply DRC gain interpolation, a crushed 1 kHz sine wave with noise bursts is reproduced. |
xHE-AAC
Download File
Reference decoder output - Generated with a decoder target loudness setting of -16 LKFS and DRC processing enabled
Test 4: Limiter Test
| Audio | Modulated sine wave with low-level harmonic distortion |
| Test | This item tests whether the decoder applies peak limiting. |
| Expected Output | If the decoder correctly applies peak limiting, a modulated sine wave with low-level harmonic distortion is reproduced. If the decoder does not apply peak limiting, a modulated sine wave with high-level harmonic distortion is reproduced. |
xHE-AAC
Download File
Reference decoder output - Generated with a decoder target loudness setting of -16 LKFS
Troubleshooting
MPEG-D DRC support is mandatory for xHE-AAC bitstreams and decoders and all test streams on this page should play properly on any xHE-AAC decoder.