On Fri, 06 May 2011 14:35:28 +0200, a...@p...pl wrote:

>Czesc,
>
>a szukalem sobie cos takiego jak dvb-t2 recorder. I sa juz na
>brytyjskim rynku - same tunery dvb-t2 sa juz ok. 80 funtow (moze
>taniej, moze drozej). Wiec nie wiem, czy jest sens kupowac cos, co
>bedzie tylko dvb-t mpeg-4. Ale nie o tym.
>
>Chodzi o dzwiek. Nie tak dawno TVN w NTC (dvb-t) przeprowadzil testy
>dzwieku AC-3 (bez sciezki mpeg) i niektore tunery zamilkly. A co
>bedzie, jak uzyjac E-AC3 - ktory niby jest dozwolony w NTC w PL.
>Pewnie druga polowa zamilknie.
>
>Np. taka Norwegia w swojej NTC (dvb-t mpeg-4) uzywa HE-AAC (zwane
>AAC+). Co ciekawe (chyba) Dolby Laboratories kupilo sobie Coding
>Technologies (od AAC).
>
>Poza tym w UK w dvb-t2 czytalem, ze ma byc/jest juz dzwiek w HE-AAC
>(AAC+) bo mniej potrzeba do transmisji dzwieku przestrzennego, niz
>jakby uzywac AC-3.
>
>Ja nie jestem specem w tej dziedzinie, ale zaczynam wymiekac w
>rozumowaniu.
>
>Co kraj to obyczaj (a dokladnie specyfikacja). Czy znowu musi byc taki
>sam burdel, jak kiedys z systemami tv (obraz, dzwiek, pal
>b/g/d/k/i/h/.....5.5Mhz, 6,5Mhz, kanaly 6/7/8MHz....).
>
>Kupilbym sobie PVR z dvb-t2 i miec spokoj, bo w PL pewnie i tak
>wprowadza dvb-t2. Nie wierze, ze bedzie inaczej. Obraz widac, ze
>wszedzie bedzie mpeg-4 avc, ale co z dzwiekiem?
>
>Jak inne kraje, ktore juz weszly w dvb-t2 (szwecja, austria, czechy
>testy)? Co mozna sie spodziewac po Niemcach/Francuzach....
>
>A nie mozna byloby wyprodukowac tunera, co ma slot...i jak czegos
>braknie, to idziemy do Biedronki i kupujemy modul do wsadzenia z
>HE-AAC i mamy "brakujacy" dzwiek? Tak, jak kiedys z rownoleglo fonia?
>
>Czy TV z dvb-t sprzedawane w PL rzeczywiscie sa zgodne z zaleceniami i
>maja AC3 i E-AC3?
>
>Pomocy, bo sie przegrzeje!


szukajac jak to bedzie z tym audio, to natknalem sie na specyfikacje
slovenskich odbiornikow i tam jest sporo na temat HE-ACC

http://igorfuna.com/dvb-t/slovenia/specifications-fo
r-slovenian-dvb-t-receivers

Moglby to ktos przejrzec i skomentowac?

Z pobierznego przejrzenia wynika tak, ze ich sprzet pod wzgledem audio
ma wszystko co potrzeba.

AC-3, E-AC3, HE-ACC....na wyjsciach cyfrowych (pass lub transcodowanie
do AC-3 jak potrzeba, analogowych (downmixy)

Po testach w NTC z fonia AC-3 (bez fonii mpeg) wyszlo, ze czesc
sprzetu nie robila downmix to stereo. Czy takie specyfikacje sa w
polskich wytycznych??



-------
8 Audio Decoder
8.1 Requirements for Audio Decoder in SDTV Level RECEIVER

The receiver shall provide at least one stereo audio decoder that is
able to meet minimum decoding requirements based on MPEG 1 Layer II
("Musicam" ISO/IEC 11172-3) and decoder for AC3. Audio decoder shall
support also AAC* decoding according to ISO/IEC 14496-3 subpart 4 [34]
(*mandatory for devices on Slovenian market from 01.01.2010).

The Audio decoders shall fully comply with DVB Implementation
Guidelines for the use of MPEG- 2 Systems, Video and Audio in
satellite, cable and terrestrial Broadcasting Applications ETSI TS 101
154 [3].


8.2 Additional Audio Decoder requirements for HDTV Level RECEIVER


8.2.1 General

The HDTV Level receiver shall support reception of multi-channel (up
to 5.1) audio in addition to the mandatory audio requirements for SDTV
Level receivers. The HDTV Level receiver shall provide analogue audio
outputs for stereo/mono, S/PDIF output and an HDMI output for
multi-channel audio. Optionally additional analogue outputs may be
provided for additional surround sound or audio components for
additional languages and/or impaired people.

An audio output of HDTV level iDTV receiver shall be in sync with the
displayed video.

The HDTV level receiver shall be capable of decoding and down-mixing
following formats for the analogue outputs:

*
o

HE AAC (5.1 channel downmix to stereo), if HE AAC is
implemented in the receiver,
o

AC3 (5.1 channel downmix to stereo), if AC3 is implemented
in the receiver,
o

E-AC3 (5.1 channel downmix to stereo), if E-AC3 is
implemented in the receiver,
o

MPEG1 layer II (Musicam ISO/IEC 11172-3) (2 channels).

The receiver shall always have the audio signal present on the
analogue outputs (SCART and stereo out) whenever any of supported four
formats is received.

The multi-channel audio may be carried in two formats: HE-AAC [34] or
E-AC3 [33]. For receivers on the Slovenian market after 01.01.2010
both formats shall be mandatory.

HDTV services with multi-channel audio

External interfacing equipment (like TV display unit) shall not be
required to support more than 2 channel PCM audio within main
Video/Audio interface (HDMI/SCART).

The HD level receiver shall have an internal digital audio reference
level equivalent to the Dolby dialogue normalization reference level
of -31 dBFS.

The HD level receiver shall adjust the output level of all audio
decoders to match the internal reference level so that perceived
programme loudness is consistent for all audio coding schemes. For
receivers featuring E-AC3, this should be consistent with Dolby
Technical Bulletin 11: Requirement Updates for AC3 and E-AC3 in DVB
Products [34]. Receivers featuring AC3 or E-AC3 decoding shall include
the PCM Level Control feature described therein. For example, for
MPEG-1 Layer 2 audio streams that have an average loudness of about
-20 dBLeq, the receiver shall apply an attenuation of 11 dB for the
digital output to match the internal reference level.

8.2.2 Audio formats

The HDTV Level receiver shall in addition to the audio requirements
for SDTV Level receiver support the formats specified in chapters
8.2.2.1 and 8.2.2.2 of this document.


8.2.2.1 System with E-AC3 bitstream

The HDTV Level receiver shall have capabilities for processing AC3 and
E-AC3* streams. (*E-AC3 mandatory after 01.01.2010).



The receiver shall be capable of providing the following formats on
the HDMI output connector:

*
o

Pass-through of native bitstream AC3 and E-AC3* (*E-AC3
mandatory after 01.01.2010)
o

E-AC3 bitstream transcoded to AC3.
o

PCM stereo from the decoded or down-mixed bitstream.



The following formats are optional for the HDMI output connector:

*
o

PCM multi-channel from the decoded bitstream.
o

Pass-through of DTS bitstream.


The receiver shall be capable of providing the following formats on
the S/PDIF connector:

*
o

E-AC3 bitstream transcoded to AC3
o

PCM stereo from the decoded or down-mixed bitstream
o

Pass-through of AC3 bitstream



Pass-through of DTS bitstream to the S/PDIF connector is optional.



The receiver shall:

*
o

Decode AC3 streams at all bit rates and sampling rates
listed in ETSI TS 102 366 [33] (not including Annex E).
o

(additionally) decode E-AC3 streams with data rates from
32 kbit/s to 3 024 kbit/s and support all sample rates listed in TS
102 366 [33] Annex E.
o

Be capable of transcoding E-AC3 bitstreams to AC3
bitstreams according to ETSI TS 102 366 [33].



Transcoding to AC3 audio streams shall be at a fixed bit rate of at
least 640 kbit/s.

The receiver shall support the use of Dolby metadata [33] embedded in
the audio stream when decoding AC3 or E-AC3 bitstreams, transcoding
E-AC3 bitstreams to AC3, or creating a PCM stereo downmix from a
decoded E-AC3 or AC3 bitstream.


8.2.2.2 System with HE AAC bitstream

The HDTV Level shall have capabilities for processing HE AAC* streams
(*HE-AAC mandatory after 01.01.2010).



The receiver shall be capable of providing the following formats on
the HDMI output connector:

*
o

Pass-through of native HE AAC bitstream (*HE-AAC mandatory
after 01.01.2010)
o

Multichannel HE AAC bitstream transcoded to AC3 or DTS.
o

PCM stereo from the decoded or down-mixed bitstream



The following formats are optional for the HDMI output connector:

*
o

PCM multi-channel from the decoded bitstream.
o

Pass-through of DTS bitstream.



The receiver shall be capable of providing the following formats on
the S/PDIF connector:

*
o

PCM stereo from the decoded or down-mixed bitstream.
o

Multichannel HE AAC bitstream transcoded to AC3 or DTS.



Pass-through of DTS bitstream to the S/PDIF connector is optional.



The receiver shall:

*
o

be capable of decoding HE AAC Level 2 (mono, stereo) at
sampling rates of 48 kHz according to ETSI TS 101 154 [3], Annex H.
o

be capable of decoding HE AAC Level 4 (multi-channel, up
to 5.1) at sampling rates of 48 kHz according to ETSI TS 101 154 [3],
Annex H (downmix).
o

be capable of transcoding HE AAC Level 4 (multi-channel,
up to 5.1) at sampling rates of 48 kHz according to ETSI TS 101 154
[3], Annex H to AC3 or DTS.



If supported, transcoding to AC3 audio streams shall be according to
ETSI TS 102 366 [33] at a fixed bit rate of 640 kbit/s.

If supported, transcoding to DTS audio streams shall be according to
TS 102 114 [24] at a fixed bit rate of 1,536 Mbit/s.

The HDTV level receiver shall support the use of the following HE AAC
metadata embedded in the audio stream when decoding HE AAC and
transcoding HE AAC multichannel to AC3 or DTS:

*
o

Dynamic Range Control according to ISO/IEC 14496-3 [34]
o

Program Reference Level according to ISO/IEC 14496-3 [34]
o

Mix Down Parameters according to "Transmission of MPEG4
Ancillary Data" part of DVB specification ETSI TS 101 154 [3]



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