hash stringlengths 32 32 | doc_id stringlengths 7 13 | section stringlengths 3 121 | content stringlengths 0 2.2M |
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79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.1 Purpose | This element contains the configuration for an AC-4 decoder. An AC-4 decoder shall only be configured by the ac4_toc() (as opposed to information available on system level). |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2 ac4_toc - AC-4 table of contents | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.1 bitstream_version - bitstream version | This element indicates the bitstream version of the AC-4 codec frame. It is a 2-bit element that can be extended by variable_bits(). Only bitstreams with a bitstream version of 0 and 1 are decodable using this version of the AC-4 specification. Bitstreams with a bitstream version of 2 or higher are not decodable accord... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.2 sequence_counter - sequence counter | This element contains the sequence counter value for the current AC-4 frame. Using the sequence counter, a decoder can detect uncontrolled changes in the stream source, such as might occur in splicing operation. Normal operation A decoder may continue its usual processing if one the following conditions is met: • Count... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.3 b_wait_frames | This Boolean indicates whether wait_frames information follows in the bitstream. Otherwise, wait_frames is undefined. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 73 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.4 wait_frames | For Average Bit Rate (ABR) streams, this element indicates when decoding of this frame can begin. After having received the frame carrying wait_frames, a decoding system should wait for wait_frames frames before the decoded frame is placed into the output buffer, unless other timing information exists. Refer to table 8... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.5 fs_index - Sampling frequency index | This element indicates the base sampling frequency, identified by the variable base_samp_freq, as shown in table 82. Table 82: Base sampling frequency fs_index base_samp_freq (kHz) 0 44,1 1 48 ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 74 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.6 frame_rate_index - frame rate | This element indicates the rate of frames, frame_rate, in units of fps (frames per second), the value of frame_length indicating the length of the frame in samples (dependent on the external sample rate) and the decoder resampling ratio as shown in table 83 and table 84. The base codec frame length value, frame_len_bas... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.7 b_iframe_global - global I-frame flag | This Boolean indicates whether all substreams in all presentations have b_iframe set to true. If frame_rate_factor ≠ 1, this is fulfilled if the first b_iframe of a series of 2 or 4 substreams is true. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.8 b_single_presentation - single presentation flag | This Boolean indicates whether a single presentation is present. Otherwise, b_more_presentations and additional variable_bits are used to derive the number of presentations contained in the AC-4 frame. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 75 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.9 b_more_presentations - more presentations flag | This Boolean indicates whether the number of presentations, n_presentations, is derived from additional variable_bits. Otherwise, no presentation is contained in the AC-4 frame. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.10 b_payload_base - payload base flag | This Boolean indicates whether payload base offset information follows in the bitstream. Otherwise, the payload base offset is 0 and the first ac4_substream_data immediately follows the ac4_toc element. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.11 payload_base_minus1 - payload base offset minus 1 | This element indicates the start of the ac4_substream_data for substream 0 relative to the end of the byte-aligned ac4_toc element in bytes minus 1. It is a 5-bit element that is extended by variable_bits() for a value of 0x1f. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.2.12 byte_align - byte alignment bits | This element is used for the byte alignment of the ac4_toc() element. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3 ac4_presentation_info - AC-4 presentation information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.1 b_single_substream - single substream flag | This Boolean indicates whether the presentation contains a single substream. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.2 b_belongs_to_presentation_id - Presentation identifier assignment flag | This Boolean indicates whether the presentation belongs to a presentation identifier. The presentation identifier, presentation_id, is derived from additional variable_bits. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.3 b_hsf_ext - high sampling frequency extension flag | This Boolean indicates whether additional spectral data is available that can be used for decoding a presentation into 96 kHz or 192 kHz. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.4 presentation_config - presentation configuration | This element indicates the presentation configuration. It is a 3-bit element that is extendable by variable_bits(). The mapping of the presentation configuration to the substream type of each substream is shown in table 85. Table 85: presentation_config to substream type mapping for presentation_version = 0 presentatio... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.5 b_pre_virtualized - pre-virtualized flag | This Boolean indicates whether the audio content in the current presentation was pre-rendered by a headphone virtualizer. In this case, the receiving device/service may choose to turn off device-side content postprocessing. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 76 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.6 b_add_emdf_substreams - additional EMDF substreams flag | This Boolean indicates whether additional Extensible Metadata Delivery Format (EMDF) substreams are present. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.7 n_add_emdf_substreams - number of additional EMDF substreams | This element indicates the number of additional EMDF substreams. It is a 2-bit element that is extendable by variable_bits(), |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.3.8 md_compat - compatibility indication | This field indicates the decoder compatibility as shown in table 86. The md_compat element indicates decoder systems that are compatible with a presentation. A system with compatibility level n shall decode all presentations with md_compat ≤ n. A system with compatibility level n should not decode (i.e. select) present... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.4 presentation_version - presentation version information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.4.1 b_tmp - temporary flag | One or more sequential instances of this element signal the version of the presentation (i.e. it might be present multiple times). An encoder conforming to the present document shall write a presentation version value of 0. A decoder implemented in accordance with the present document shall not decode a presentation if... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.5 frame_rate_multiply_info - frame rate multiplier information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.5.1 b_multiplier - multiplier flag | This Boolean indicates whether the frame_rate_factor value is determined by the provisions of clause 4.3.3.5.3. Otherwise, or if the Boolean is not present, the frame_rate_factor value is 1. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.5.2 multiplier_bit - multiplier bit | If set, this bit indicates a frame_rate_factor value of 4 and if not set, a frame_rate_factor value of 2. See clause 4.3.3.5.3. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.5.3 frame_rate_factor - frame rate factor | The value of this element, as specified in table 87, determines whether an ac4_substream_info() element refers to 1, 2, or 4 substreams. Each of those substreams shall be decoded consecutively. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 77 Table 87: frame_rate_factor frame_rate_index b_multiplier multiplier_bit frame_rate... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.6 emdf_info - EMDF information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.6.1 emdf_version - EMDF syntax version | This element indicates the syntax version that the EMDF substream conforms with. It is a 2-bit element that can be extended by variable_bits(). For substreams that conform to the syntax defined in this version of the AC-4 specification, the emdf_version field shall be set to 0. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.6.2 key_id - authentication ID | This element is a 3-bit element that can be extended by variable_bits(). The present document defines no semantics on its value. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.6.3 b_emdf_payloads_substream_info - EMDF payloads substream information flag | This Boolean indicates whether an emdf_payloads_substream_info() element is present. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7 ac4_substream_info - AC-4 substream information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.1 channel_mode - channel mode | This element indicates the channel mode and the ch_mode variable as shown in table 88. The element has a variable length of 1, 2, 4, or 7 bits that can be extended by variable_bits(). Table 88: channel_mode Value of channel_mode Channel mode ch_mode 0 Mono 0 10 Stereo 1 1100 3.0 2 1101 5.0 3 1110 5.1 4 1111000 7.0: 3/4... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.2 b_sf_multiplier - sampling frequency multiplier flag | This Boolean indicates whether the sampling frequency of the AC-4 substream is a multiple of the base sampling frequency. Otherwise, the sampling frequency of the AC-4 substream is identical to the base sampling frequency. NOTE: b_sf_multiplier is only available if the base sampling frequency is 48 kHz. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.3 sf_multiplier - sampling frequency multiplier bit | This element indicates the sampling frequency multiplier. Since this bit is only available if the base sampling frequency is 48 kHz, the sampling frequency of the AC-4 substream is given by table 89. Table 89: AC-4 substream sampling frequency for a base sampling frequency of 48 kHz b_sf_multiplier sf_multiplier Sampli... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.4 b_bitrate_info - bit-rate presence flag | This Boolean indicates whether a bit rate indicator is specified. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.5 bitrate_indicator - bit-rate indicator | This element indicates the upper limit of the average bit-rate per channel in the substream and the variable brate_ind as shown in table 90. "Per channel" refers to the number of all audio channels in the substream with the exception of LFE channels that have the b_lfe flag set in mono_data() structure. Table 90: bitra... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.6 add_ch_base - additional channels coupling base | This element indicates whether the A-CPL coding of the additional channels (Lw/Rw or Tfl/Tfr depending on channel_mode) is based on the L/R pair (add_ch_base = 0) or on the Ls/Rs pair (add_ch_base = 1). See clause 5.7.7.6.3 for details. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.7 b_content_type - content type presence flag | This Boolean indicates whether a content type is specified. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.8 b_iframe - I-frame flag | This Boolean is set for each of the frame_rate_factor substreams, indicating that this frame is an I-frame. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 79 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.7.9 substream_index - substream index | This element indicates the substream index that the ac4_substream_info() element refers to. It is a 2-bit element that can be extended by variable_bits(). The substream index is used as index in the substream_index_table() element to get the offset to ac4_substream(). If frame_rate_factor is not 1, substream_index refe... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8 content_type - content type | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.1 content_classifier - content classifier | This element classifies the content of an audio program component as shown in table 91. Table 91: content_classifier Value of content_classifier Content classification (audio program component type) 000 complete main 001 music and effects 010 visually impaired 011 hearing impaired 100 dialogue 101 commentary 110 emerge... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.2 b_language_indicator - presentation language indicator flag | This Boolean indicates whether the presentation language indicator, identifying the language of the presentation, is available. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.3 b_serialized_language_tag - serialized language tag flag | This Boolean indicates whether the presentation language tag is delivered using multiple payloads in a sequence of AC-4 frames. Otherwise, the language tag is completely delivered in the current payload. The value of b_serialized_language_tag remains to be set to 1 in all frames that follow the frame in which both the ... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.4 b_start_tag - language tag start flag | This Boolean indicates the start of a multi-frame sequence of language tag data in language_tag_chunk. In this case the language_tag_chunk contains the first chunk of the language tag; decoders shall start decoding the language tag beginning with the data in this payload. Otherwise, language_tag_chunk does not contain ... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.5 language_tag_chunk - language tag chunk | The element contains a two-byte section of a language tag. The most significant byte of the language tag is stored in the most significant byte of the language_tag_chunk together with b_start_tag indicating the start of a new language tag sequence. Subsequent bytes of the language tag are stored in the second byte of t... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.6 n_language_tag_bytes - number of language tag bytes | This element indicates the total length, in bytes, of the language tag in language_tag_bytes. Values of 0 and 1 and values of 43 to 63 are reserved. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.7 language_tag_bytes - language tag bytes | Decoders shall read and interpret the sequence of language_tag_bytes as one complete language tag that conforms to the syntax and semantics defined in IETF BCP 47 [3]. The minimum sequence length is two bytes, supporting a two- character language tag as specified in ISO 639 [4]. The maximum supported length of the lang... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.8.8 Special codes on language_tags_bytes for substreams of type associated audio | To refine the content classification on substreams of type associated audio compared to what's provided through the content_classifier according to clause 4.3.3.4, special codes may be utilized with language_tag_bytes. In addition to more detailed information about the associated audio type, these codes allow to signal... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.9.1 n_skip_bytes - number of bytes to skip | This element specifies the number of bytes to skip. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 81 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.9.2 b_more_skip_bytes - more bytes to skip flag | This Boolean indicates whether the number of bytes to skip, n_skip_bytes, is extended by the use of variable_bits(). |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.9.3 reserved - Reserved | This element is reserved for future use and the content shall be skipped by an AC-4 decoder conforming to the present document. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.10 ac4_hsf_ext_substream_info - AC-4 HSF extension substream information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.10.1 substream_index - substream index | This element indicates the substream index that the ac4_hsf_ext_substream_info element refers to. It is a 2-bit element that can be extended by variable_bits(). The substream index is used as index in substream_index_table() to get the offset to ac4_substream() for the high sampling frequency extension substream. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.11 emdf_payloads_substream_info - EMDF payloads substream information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.11.1 substream_index - substream index | This element indicates the substream index that the emdf_payloads_substream_info element refers to. It is a 2-bit element that can be extended by variable_bits(). The substream index is used as index in substream_index_table() to get the offset to emdf_payloads_substream(). |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.12 substream_index_table - substream index table | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.12.1 n_substreams - number of substreams | This element indicates the number of substreams available in substream_index_table. It is a 2-bit element that can be extended by variable_bits(). |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.12.2 b_size_present - size present flag | This Boolean indicates whether the substream size is present. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.12.3 b_more_bits - more bits flag | This Boolean indicates whether additional variable_bits() are used to determine the substream size. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.3.12.4 substream_size - substream size | This element indicates the substream size in bytes for the substream with index s. It is a 10-bit element that can be extended by variable_bits(). To get the offset for the nth substream relative to the end of ac4_toc, the substream sizes of the substreams with a substream index less than n need to be accumulated as sh... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.4 ac4_substream - AC-4 substream | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.4.1 audio_size_value - audio size value | This element indicates the audio_size in bytes. It is a 15-bit element that can be extended by variable_bits(). The audio_size is the size of the audio_data element including any following fill_bits and byte_align bits but not including the size of the metadata element and the final byte_align bits. NOTE: This enables ... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.4.2 b_more_bits - more bits flag | This Boolean indicates whether additional variable_bits are present, to be used for the audio_size determination. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.4.3 byte_align - byte alignment bits | This element is used for byte alignment within the ac4_substream() element. An encoder shall use this field to pad the length of ac4_substream to an integer number of bytes. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5 Channel elements | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.0 Introduction | This clause describes the bitstream elements that can be found in single_channel_element, mono_data, channel_pair_element, stereo_data, 5_X_channel_element, and 7_X_channel_element. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.1 mono_codec_mode - mono codec mode | The value of this element indicates the mono codec mode as shown in table 93. Table 93: Mono codec mode mono_codec_mode Mono codec mode 0 = SIMPLE Simple 1 = ASPX advanced spectral extension |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.2 spec_frontend - spectral frontend selection | The value of this element indicates the used spectral frontend as shown in table 94. Table 94: Spectral frontend selection spec_frontend Spectral frontend 0 = ASF Audio Spectral Front end 1 = SSF Speech Spectral Front end The bitstream elements spec_frontend_m, spec_frontend_s, spec_frontend_l, and spec_frontend_r are ... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.3 stereo_codec_mode - stereo codec mode | The value of this element indicates the stereo codec mode as shown in table 95. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 83 Table 95: stereo_codec_mode stereo_codec_mode Stereo codec mode 0 = SIMPLE Simple 1 = ASPX A-SPX 2 = ASPX_ACPL_1 A-SPX, A-CPL mode 1 3 = ASPX_ACPL_2 A-SPX, A-CPL mode 2 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.4 3_0_codec_mode - 3.0 codec mode | The value of this element indicates the 3.0 codec mode as shown in table 96. Table 96: 3_0_codec_mode 3_0_codec_mode 3.0 codec mode 0 = SIMPLE Simple 1 = ASPX Advanced SPectral eXtension (A-SPX) |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.5 3_0_coding_config - 3.0 coding configuration | This element indicates the coding configuration for the 3.0 channel mode. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.6 5_X_codec_mode - 5.X codec mode | The value of this element indicates the 5.X codec mode as shown in table 97. Table 97: 5_X_codec_mode 5_X_codec_mode 5.X codec mode 0 = SIMPLE Simple 1 = ASPX A-SPX 2 = ASPX_ACPL_1 A-SPX, A-CPL mode 1 3 = ASPX_ACPL_2 A-SPX, A-CPL mode 2 4 = ASPX_ACPL_3 A-SPX, A-CPL mode 3 5…7 Reserved |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.7 7_X_codec_mode - 7.X codec mode | The value of this element indicates the 7.X codec mode as shown in table 98. Table 98: 7_X_codec_mode 7_X_codec_mode 7.X codec mode 0 = SIMPLE Simple 1 = ASPX A-SPX 2 = ASPX_ACPL_1 A-SPX, A-CPL mode 1 3 = ASPX_ACPL_2 A-SPX, A-CPL mode 2 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.8 coding_config - coding configuration | This element indicates the coding configuration for the 5.X or the 7.X channel mode. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.9 2ch_mode - channel coupling mode | The value of this element indicates the way channel pairs are coupled into the output channels. See clause 5.3.4.3 and clause 5.3.4.4.0 for details. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 84 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.10 b_enable_mdct_stereo_proc - enable MDCT stereo processing flag | This Boolean indicates whether MDCT domain stereo processing data that is stored in a chparam_info element, is present. The sf_info element, which is also enabled by this Boolean, holds audio spectral front end (ASF) information that is valid for the decoding of both sf_data elements that follow. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.11 chel_matsel - matrix selection code | This element indicates the matrix for multichannel coupling. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.12 b_use_sap_add_ch - use SAP for additional channels flag | This Boolean indicates whether the SAP tool shall be used for the additional channels and that SAP data stored in two chparam_info() elements shall follow in the bitstream. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.5.13 max_sfb_master - max_sfb indication for related channels | This element indicates the max_sfb value to be used when decoding the two sf_data() elements, which follow the max_sfb_master element and the two chparam_info() elements. The max_sfb value for various block sizes is shown in table B.8 to table B.19. The table to use depends on the largest signalled transform length whi... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6 audio spectral front end | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.1 asf_transform_info - ASF transform information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.1.1 b_long_frame - long frame flag | This Boolean indicates whether the audio frame is a long frame. A long frame contains just one (full) block that needs to be transformed. The transform length for a long frame depends on the sampling frequency and the frame_len_base value and is given by table 99. Table 99: Transform length for long frames frame_len_ba... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.1.2 transf_length[i] - transform length index i | The value of this element is used to derive the transform length for partial blocks if the frame_len_base value is greater or equal to 1 536. An audio frame contains several partial blocks if the audio frame is not a long frame. All partial blocks that make up the first half of a corresponding full block use index 0 an... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.1.3 transf_length - transform length | The value of this element is used to derive the transform length for the audio block or the partial blocks if the frame_len_base value is less than 1 536. Table 103 through table 105 show the transform length values depending on the sampling frequency and the frame_length value. Table 103: Transform length for frame_le... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.2 asf_psy_info - ASF psy information | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.2.1 n_msfb_bits - number of maxsfb bits | The number of bits used for the max_sfb[i] and max_sfb_side[i] elements depends on the transform length and is determined by the value of n_msfb_bits in table 106 through table 108. The number of bits for max_sfb[0] in the sf_info_lfe() element is determined by the value of n_msfbl_bits in table 106 through table 108. ... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.2.2 max_sfb[i] - number of transmitted scale factor bands for index i | This element is used for a full block or all partial blocks related to transf_length[0] and max_sfb[1] is used for all partial blocks related to transf_length[1]. Depending on the value of the transform length, this is a 4-bit, 5-bit or 6-bit integer value indicating the number of transmitted scale factor bands in asf_... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.2.4 n_grp_bits - number of grouping bits | The number of grouping bits is 0 if b_long_frame is true and the frame_len_base value is greater or equal to 1 536. If b_long_frame is false and the frame_len_base value is greater or equal to 1 536, the number of grouping bits n_grp_bits depends on transf_length[0], transf_length[1], and the frame_len_base value, and ... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.2.5 scale_factor_grouping_bit - scale factor grouping bit | This element, which is present n_grp_bits times, is used to indicate the scale factor grouping. The conversion of the scale_factor_grouping[i] array into asf_psy_info helper elements is specified in clause 4.3.6.2.6. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 90 |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.2.6 asf_psy_info helper elements | The following helper elements are derived from the asf_psy_info bitstream elements, especially from the scale_factor_grouping[i] array: • num_windows Number of (transform) windows within the current audio frame. Possible values are: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, and 16. • num_window_groups Number of window groups. • ... |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.3 asf_section_data - ASF section data | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.3.1 sect_cb[g][i] - section codebook | This element indicates the Huffman codebook to be used for section i in group g. The values 12 to 15 do not indicate a Huffman codebook and shall not be used. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.3.2 sect_len_incr - section length increment | This element is used for determining the section length of section i in group g. The length of the sect_len_incr field itself, n_sect_bits, depends on the transform length as shown in the pseudocode below. Pseudocode 6 if (transf_length_g <= 2) { n_sect_bits = 3; } else { n_sect_bits = 5; } |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.4 asf_spectral_data - ASF spectral data | |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.4.1 asf_qspec_hcw - Huffman coded quantized spectral lines | This element holds Huffman coded quantized spectral lines. Either two or four spectral lines, indicated by the used Huffman codebook dimension, are coded with one codeword. |
79462c15429e4b02e874d57a1faa88a5 | 103 190-1 | 4.3.6.4.2 huff_decode(hcb, hcw) - Huffman decoding | This function takes a Huffman codebook table and a Huffman codeword as input and returns the index of the Huffman codeword in the Huffman codebook table. ETSI ETSI TS 103 190-1 V1.4.1 (2025-07) 92 |
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