Data: 2011-05-12 09:23:50 | |
Autor: adresss | |
audio w dvb-t - jak to jest/bedzie | |
On Fri, 06 May 2011 14:35:28 +0200, adresss@poczta.pl wrote:
Czesc, 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-for-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] -- ThinkXtra |
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Data: 2011-05-12 11:53:13 | |
Autor: pravus | |
audio w dvb-t - jak to jest/bedzie | |
On Thu, 12 May 2011 09:23:50 +0200, adresss@poczta.pl wrote:
szukajac jak to bedzie z tym audio, to natknalem sie na specyfikacje Widzę że strasznie trudno znaleźć odpowiednie rozporządzenie MI. Masz więc cytacik: "13. Dekoder sygnału fonii Dekoder sygnału fonii powinien dekodowaç stru- mienie cyfrowe fonii zakodowane zgodnie z MPEG-2 Warstwa II zgodnie z ISO/IEC 13818-3 [12] i ogranicze- niami zawartymi w ETSI TS 101 154 [8] część 6.1 oraz E-AC-3 zgodnie z ETSI TS 102 366 [10] i ograniczenia- mi zawartymi w części 6.2 ETSI TS 101 154 [8]. Dekoder sygnału fonii powinien wykorzystywać metadane przesyłane w strumieniu E-AC-3 do norma- lizacji siły głosu, konwersji dźwięku przestrzennego do stereofonicznego lub mieszania głównej składo- wej fonii z dodatkowymi. Niezależnie od systemu kodowania i liczby transmi- towanych kanałów fonicznych, dekoder sygnału fonii powinien dostarczać sygnał stereofoniczny do wyjś- cia analogowego fonii odbiornika cyfrowego, chyba że nadawany jest sygnał monofoniczny lub dwa dźwięki. Wówczas dekoder powinien dostarczać na obu kanałach sygnał monofoniczny wybrany przez użytkownika." A to że spora część aktualnie sprzedawanego u nas sprzętu wymagań z rozporządzenie nie spełnia to już inna sprawa. |
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