Category Archives: its HDTV

Freebox support DTS Neural

Following the announcement of the partnership in April 2012 with DTS, Free advertisement support DTS Neural Surround, a process that can take advantage of a 5.1 which is transported in a matrixed stereo LtRt flow and must be specifically addressed upstream and distribution "for an equivalent rate, channels and VOD portals can now offer HD 5.1 sound." Note that the Freebox is not the first to include this technology as Bbox Bouygues Telecom sensation already offers it since September 2013 . Which content is concerned? A priori, Freebox, DTS Neural contribution will be made ​​exclusively for VOD.


Recommendation R128

After a long work in the EBU Ploud group that brings together the various players in the Broadcast in Europe, the R128 recommendation is finalized, online here on the website of the EBU. See also the excellent educational document "On the way to nirvana loudness" of Florian Camerer here .

To summarize here the main lines

To characterize the audio signal, the following parameters are used:

- Measurement of program loudness (loudness program)

- Excursion loudness (loudness range, LRA)

- Signal peak (maximum true peak level) level

There are three types of measures:

- Instantaneous measurement (momentary loudness): sliding window of 400 ms

- Measuring short term: sliding window 3s

- The infinite measure (integrated loudness) over the duration of the program

The value of the measurement of program loudness is normalized to -23 LUFS + - 1 LU

The scale is equivalent to LUFS LKFS scale (weighting curve R2LB or K) with the following correspondence

LU = 0 -23 LUFS

Two scales are used for the metering:

- EBU +9 scale, the default scale ranging from -18 to +9 LU LU (-41 LUFS - 14 LUFS)

- EBU +18 scale ranging from -36 to + 18 LU LU (-59 LUFS LUFS -5)

The audio signal to be measured in its entirety, without considering specific items such as dialogues

The measure must incorporate the use of gate, whose relative threshold is 10 LU below the value of loudness, obtained by flash measurement (400 ms). Also note the presence of a gate to the silences, the threshold is set at -70 LUFS.

The loudness range (LRA), translated the tour loudness during the program, the measurement algorithm fontionne retained on the statistical distribution of values ​​between 5% and 95%, and excluding outliers. The LRA has no value imposed in R128 standard, it's just not recommended to exceed 20 LU for broadcast television program with wide dynamic range (the film, classical music).

Towards a new loudness normalization EBU / UER


The EBU / EBU Loudness P / LOUD group, orchestrated by Florian Camerer, working for some time on new standards for measuring loudness. The lounge of the IBC was an opportunity for further discussion on these standards. In short, this is what can be learned from these initial recommendations:

normalization of peaks MAX -1dBFS true peak

3 time constants for the measurement of loudness:

long term (infinite), use of a measure with gate so do not take into account the low level passages

threshold of the gate = 7 LU below the measured loudness or absolute value (please specify)

short term 10 or 8s

momentary between 100 and 500 ms

target value of loudness = - 23 + LKFS - 1 LU

taken into account for the measurement of the LFE

More: P / LOUD

PAD standard HDTV CST-RT-019

This new standard, being signed, complements CST recommendation - RT 017 to define the evaluation of sound dynamics methodologies.

- Scaling measuring loudness: LKFS weighting curve Leq (R2LB)

ITU-R weighting BS.1770-1

- Average level dialogue s LKFS -25 + - 2 dB


- Methodology for measuring e dynamiqu

tours of loudness following are allowed:

s for dialogue: + - 7 dB measured in the short term in the Dialog level

for all the sound elements of the program: + - 12 dB measured in the short term in the Dialog level

Management peaks mixing 5.1 -3 dB FS (eventually extended to all flavors mixing, 5.1, LtRt, LoRo, Dual mono)


information and diagrams from the technical recommendation CST-RT-019-TV-2009-V1

More: CST

SoundCode Neyrinck Dolby E


cf Neyrinck Audio

Neyrinck Audio has to offer its SoundCode implementation for encoding Dolby E. This tool, developed for pro tools and as a standalone application, is a kind of update for Broadcast SoundCode released last year. It can encode and decode a Dolby E file so it can export a file MBWF (files carrying eight channels of audio supports 5.1 +2) pcm interlaced integrating metadata for Dolby DP600 for encoding Dolby E, Dolby Digital, Dolby Surround as well as analysis and loudness correction. Note the ability to import and export in pro tools MBWF of interleaved files for 5.1 that are larger than 4GB (RIFF64).

A test, more audio Neyrinck


cf Neyrinck Audio

Dolby E encoder overcodes Minnetonka


Minnetonka has released the famous Dolby E encoder as expected. Until then, we can decode a Dolby E in pro tools or VST or as a standalone application ... Today we can encode. Usage is very simple, just to provide metadata to the application that will make a wav file Dolby E, these metadata are obtained so far with the DP570 (until a version of Dolby plug-in so ...). We tested in AudioSuite encoding in pro tools and decoding without any problems. Finally, we lack the DRC simulation to educate these metadata because we Dolby Media Meter and LM5D for measuring the loudness, and SurCode Pro Logic 2 Minnetonka that simulates LtRt format. Overcodes rotates AudioSuite, RTAS for Pro Tools, VST and as a standalone application with AudioTools AWE.

The various programs are supported including Dolby E 5.1 ​​+ 2, a Metadata Import option allows you to import metadata from an XML file or a wav file containing the DBMD chunk.


cf Minnetonka Audio

It remains to synchronize the file wav Dolby E with HD video streams in compliance with Dolby standards (good positioning of Dolby E data on the sample 37 and proper positioning of the wav file Dolby E in the reproductive system to the SDI output) , a point that remains delicate.

More: Minnetonka Audio LtRt

Update on 5.1 encoding tools and measuring loudness in pro tools

Pro tools remains one of the best suited for multichannel output software offering many treatment options 5.1 as plug-ins developed by many manufacturers (TC electronic, Dolby Laboratories, Minnetonka Audio, Neyrinck, Soundfield, Waves ...)

Among these tools fit in a fun way in our mixer 5.1, LM5D TC electronic is essential to put an insert in our master 5.1. It gives us the history of the loudness (LeqRLB), its instantaneous value and the average value ("center of gravity") over the life of rolling program (no window of 10 seconds measurement method "short term" used by the DP570). We also have access to some sort of standard deviation, "Consistency," which gives us information on the change in loudness over the duration of the program: we have a very constant loudness or highly variable? Ppm level measurement is accurate and complete what is lacking in pro tools, accurate measurement of levels. The LM5D LM5 that differs from these statistics. For a measure of the central channel carrying the dialogues, just cut the other bus from our master 5.1. The LM5D was recently presented at IBC, and has recently become available for download on the manufacturer's website.

Among the new recently developed plug-ins, we have the overcodes Dolby E audio Minnetonka RTAS format that enables us to decode a Dolby E stream; the tool is also available as a standalone application Minnetonka AudioTools AWE. We were able to test it on different sizes (5.1, LtRt) (2 + 2) (5.1). This tool gives us the metadata informed about the various programs. Simply insert the plug-in in a track to 7.1 and route the track to a 7.1 BUS that will monitor the 5.1 and LtRt via the input to respectively 5.1 and stereo formats.

The boundaries of the plug-in is unable to export at present metadata to the DP570 and the inability to decode Dolby E in the timeline, we are obliged to indicate in the file browser Dolby E wav interlaced (sync is done early in the session or the TC if the TC is embedded in the Dolby E). A settings page brings up the port that would transport the metadata externally on the DP570 but for now is not operational. We can reverse the order of bus, in the settings page, to work with different standards smpte, movie ...

The LtRt from Dolby E itself can be decoded by another tool developed by Minnetonka Audio SurCode Dolby Pro Logic 2 This plug-in gives access to various parameters (movie or music, panorama mode ...) Pro Logic decoder 2 and it can encode in LtRt with a limiter and a gain for LR LSRS C and LFE.

It is also possible to encode and decode a Dolby Surround in pro tools using the plug-in TDM format developed by Dolby, Dolby Surround Tools. It encodes a LtRt from a LCRS Dolby Surround and Pro Logic decoding in one.

In the family of plug-ins for encoding in pro tools, we have the audio of SoundCode Neyrinck. The SoundCode Dolby Digital is used to encode and decode Dolby Digital.
We need to educate metadata (dialog level, downmix, DRC ...) measured at present by our DP570. The plug-in requires the same settings for the DRC Line Mode and RF mode oddly. The decoder can decode the stream dolby digital wav exported directly in the timeline of Pro Tools RTAS, he just have to import our stereo file into a stereo track and put the plug-in insert. This method can also be used to decode a Dolby Digital stream from a DVD player. In the window of the decoder, we can simulate the stereo and mono downmix however the DRC modes do not seem completely controlled. We have not been able to listen without DRC (?). This is a very good tool to encode Dolby Digital. The tool is also for DTS, DTS SoundCode his name.

There are also stand-alone applications in Minnetonka Audio SurCode, encoders that feature Dolby Digital, Dolby Surround, and DTS and qu'encoder for audio DVD (Disc Welder).

Another tool, the SoundCode for Broadcast is also very useful, developed by Neyrinck Audio. It helps prepare the encoding Dolby E or Dolby Digital for DP600 as files. We inform our metadata for both 5.1 and LtRt programs and can export all audio and Dolby metadata as a wav file compatible with the DP600. The SoundCode player allows us to import our Dolby E file from the DP600 and integrate it into pro tools.

cf Neyrinck

Another very interesting feature of SoundCode for Broadcast, is the ability to export and import them into pro tools for RF64 files. We can export multichannel interleaved files 6 tracks for now well over 2 GB for long-term programs size.

cf Neyrinck

Dolby developed the soft version of LM100, Dolby Media Meter. This measurement software is available as a standalone application for Mac / PC or to pro tools RTAS / AudioSuite or Minnetonka AudioTools AWE. This plug-in allows us to measure the loudness with Dialogue Intelligence technology to automatically detect passages with dialogue. The measurement can be performed on the audio formats Dolby Digital, Dolby Digital Plus, Dolby True HD, Dolby E and PCM.

We still have to wait for the Dolby E encoder Minnetonka home audio (before the end of the year?) With the equivalent of DP570 in soft to simulate the metadata in pro tools, we can always dream!

The documents in this article are from: Dolby Laboratories, Neyrinck, Minnetonka Audio, TC electronic, Digidesign.

Tests on the upmix processor Isostem

Isostem is an upmix processor for HDTV broadcast channels, based on a sound principle with a downmix "ISO" equal to the stereo. Its builder, Anthony Hurtado, has developed a technology upmix based on the analysis of energy exchanges sound at the listening position that has recently been given an AES publication. We tested the machine on a week by passing different stereo mix, music, sports, pub ...

The hardware unit has 8 inputs and 8 digital outputs AES Sub 25, and is controlled using a Windows-compatible software. The sound quality is impeccable and the parameters of spatial technologies far exceed the decoding Dolby Surround.

Indeed, the essential and the starting point of setting based on this small window, the panoramic PA analyzer, which analyzes the width or real-time correlation of the original stereo and that isolates somehow the source of its environment.

Work on the parameters of the panoramic analyzer allows us to isolate highly correlated information and extract the ghost image of the multichannel LR to create a center. We proceed in the same way information channel surround with management level extraction channel C and channel L, R. This setting is dependent on the depth of the pan law and opening angle stereo. Optimizing the adjustment can be made by monitoring the various components of the analyzer through solo and mute.

Then we have the VM virtual microphone unit, a kind of simulation of a system of multi-miking, which can de-correlate the sound image through the integration of delay and directional microphones, the approach is interesting, it adjusts the spatial correlation but delays may encourage some problems comb filter.

ISO module allows us to optimize the upmix so that the downmix is ​​identical to the original stereo, reinstating the intermix, the difference between the stereo downmix.

The output module integrates the functions of monitoring (the various channels of multi-channel, original stereo, downmix coefficients with the same Dolby and intermix) with different options (ISO optimization downmix), HCF (mitigation acute at the rear), SUB (SUB created by bass management), PHA (correction phase).

Aside from the quality upmix the Isostem also manages several independent stereo streams that can receive different stems (music, atmosphere, VO, VI ...) up to 4 stereo inputs which optimizes the sound reproduction the upmix based on stems or different versions of a program available.

A page with all the control parameters is integrated into the application.

In summary, this method already used for some HD channels in France, including France 2 HD, and HD NRJ12 offers an intelligent and promising to broadcast programs in stereo 5.1 solution. HDTV is needed because the chains are not always broadcast HD 5.1 100% native programs, it will broadcast programs from 5.1 pre-existing content in stereo and stereo stems if the spatial program of interest.

More: Isostem

Dolby E encoder and for pro tools

Minnetonka Audio released a plug-in for Pro Tools that can decode a Dolby E. The plug-in allows you to more easily integrate a multichannel Dolby E in a DAW for post-production and display metadata from the two different Flow 5.1 and stereo / LtRt.

Dolby E Encoder due out later this year.

A test!

Specifications for DTT HD, Dolby Digital + / HE-AAC

The HD forum has published the specifications for HD DTT. It is a reference document for the dissemination and reception of channels TF1 HD, France 2 HD and M6 HD. Remember that these three channels will be the first to be broadcast on TNT in 2008 are found in this document recall standards and interesting recommendations regarding multi-channel sound.

Note for sound processing (HD Forum citation):

For their HD channel, publishers plan to broadcast several audio components (VF, VO, audio description) associated with the video stream. These audio will be mono, stereo or multichannel at their convenience. Similarly, according to the program, the type of audio can vary between mono, stereo and multichannel. Note that for multi-stream support for Dolby Digital + and the HE-AAC is required, which leads to the receivers can perform downmixing of these codecs on the stereo outputs.

Transcoding a HE-AAC multichannel component to Dolby Digital or DTS will be mandatory from December 31, 2009.

Note also the integration of metadata provided in the stream HE-AAC.

Read more

HD Forum

LM5, plug-in Pro tools HD measuring Loudness

TC electronic has released a plug-in for Pro Tools HD to measure the loudness of a 5.1 program, useful in the context of multi-channel broadcasting in HDTV for example. This measure takes into account the new ITU standard dialog level Leq (RLB) incorporating weights more accurate than the Leq (A). The plug-in allows to follow the historical values ​​Loudness and it measures the PPM program values ​​with different presets. A test!

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