5/10/2021 0 Comments 5.1 Surround Sound Test Online
Notes and FAQ Multichannel on a PC Flash Test Gapless Playback Windows 7 Bugs Android Bugs Experimental Documents Contact AAC Audio Tests Site HTML5 AAC Audio Playback Tests - Multichannel Fraunhofer Institute for Integrated Circuits HE-AAC Channel ID This bitstream contains: Spoken Channel Identification in English BLITS (EBU Tech 3304-4.1) EBU Multichannel Ident (EBU Tech 3304-4.2) Narration in the following channels: FL FC FR RS LS HE-AAC Bitstream: Error: Source Statement Failure - Format not supported in this browser Download File Original Wave File: Error: Source Statement Failure - Format not supported in this browser Download File AAC-LC Channel ID This is the test above encoded in AAC-LC.AAC Bitstream: Error: Source Statement Failure - Format not supported in this browser Download File HE-AAC Channel ID - With H.264 Video Error: Source Statement Failure - Format not supported in this browser Download File This is the bitstream above multiplexed with an explanatory graphic encoded in H.264 Main Profile at 800x600 resolution.LFE and SBR Test This tests for proper bass management and reproduction of the SBR portion of the HE-AAC bitstream.
![]() This bitstream contains: Bass Management - 63 Hz tone -18 dBFS, 2 seconds Left Front Center Right Front Right Suround Left Surround LFE ( -28dBFS) SBR - 6, 8, 10, 12 kHz tones -18 dBFS, 0.5 seconds each Left Front Center Right Front Right Suround Left Surround Spoken Channel Identification in English Narration: Center channel There is a 1 kHz -18 dBFS tone in the center channel throughout. AAC Bitstream: Error: Source Statement Failure - Format not supported in this browser Download File Original Wave File: Error: Source Statement Failure - Format not supported in this browser Download File If a subwoofer is used with limited-range main speakers, all 60 Hz tones should play at the same level through the subwoofer. Hold SLM next to subwoofer) If full-range speakers are used, the 60 Hz tones should play through each speaker individually, though levels may vary due to standing wave or resonances in the listening rrom. The LFE signal is encoded 10 dB lower to account for the 10 dB gain in the LFE channel in the playback amplifers bass management circuits. If the decoder supports SBR, all four tones, 6, 8, 10, and 12 KHz should be heard (or seen on a sound level meter if you have high-frequency hearing loss). If the decoder is only decoding the AAC-LC portion of the bitstream, only the first two tones will be heard. This is at the encoded bitrate of 160 kbs, at other bitrates the SBR crossover frequency used by the encoder will vary, resulting in more or less tones being heard. Missing tones in only one channel may indicate a speaker problem. LFE and SBR Test - With H.264 Video Error: Source Statement Failure - Format not supported in this browser Download File This is the bitstream above multiplexed with an explanatory graphic encoded in H.264 Main Profile at 800x600 resolution. Troubleshooting The MPEG-4 AAC audio bitstreams above are presented as HTML5 audio objects - which should play back correctly in: Microsoft Internet Explorer 9 (Win 7 PC) Apple Safari 5 (Win 7 PC) Google Chrome (Win 7 PC, Mac OS, Android) when your computer has 5.1 channel speakers connected or connects via HDMI to a 5.1 or better surround sound AVR or home theater system. Note that many browsers and media players (particularly on mobile devices such as the iPhone) will output a stereo downmix from these streams, even if they dont support multichannel output. ![]() Channel Support The AAC codec family has supported up to 48 channels of audio since its initial development through predefined channel configurations and a flexible escape mechanism. The predefined channel configurations from the 2005 version of the AAC standard are shown below, along with the additional configurations standardized in Amendment 4 of the AAC standard in 2013 shown in cyan tint: Channel Configuration Value Channnels Speaker Mapping Common Use 0 Escape Code 1 1 Center Mono 2 2 Left, Right Stereo 3 3 Center, Left, Right 4 4 Center, Left, Right, Surround 5 5 ITU BS.775-1 6 5.1 ITU BS.775-1 5.1 Surround 7 7.1 SDDS 8-10 Reserved Value 11 6.1 12 7.1 7.1 (a) of ITU BS.2159 Blu-ray 13 Reserved Value 14 7.1 Top 7.1 (d) of ITU BS.2159 15 Reserved Value AAC Channel Configurations. Values 8-15 were added in AAC Amendment 4 This channel configuration value is specified in the AudioSpecificConfig structure of the AAC bitstream. When the channel configuration value is set to 0, the channel configuration is not predefined, but is explicitly described in the Program Config Element structure. This allows arbitrary channel configurations to be used. For information on these structures, refer to the Fraunhofer Application Bulletin AAC Transport Formats or to the MPEG AAC standard: ISOIEC 14496-3.) Supplying the 7.1 configuration with the PCE escape method was necessary since the only predefined 7.1 configuration was the theatrical SDDS speaker configuration of five front speakers and two surround speakers. Thus, the more common BluRay 7.1 configuration with three front speakers and four surround speakers was specified using the PCE structure. An amendment ( ISOIEC 14496-3:2009Amd 4:2013 ) to the AAC standard also allows signalling the BluRay 7.1 configuration in the channel configuration field by using the value 12. An AAC decoder is also required to continue decoding configurations sent in the PCE. More importantly, AAC lacked profiles requiring 7.1 support, with a level 4 or level 5 decoder only required to support 5.1 decoding. The amendment includes level 6 to require 7.1 decoding. ![]() The amendment also includes the extra loudness metadata currently specified in DVB into the AAC specification. Channel Identification Spoken Channel Identification per ISOIEC 23001-8, 48 kHz sampling rate, AOT 5, 224 kbs, explicit signalling, backwards compatible, BluRay 7.1 configuration signaled with PCE. AAC Bitstream: Error: Source Statement Failure - Format not supported in this browser Download File Original Wave File: Error: Source Statement Failure - Format not supported in this browser Download File Support of 7.1 channel bitstreams is relatively new and might not be available on many decoders. 5.1 Surround Sound Test Online Verification Of 7This bitstream is provided for verification of 7.1 decoder implementations.
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