hash stringlengths 32 32 | doc_id stringlengths 7 13 | section stringlengths 3 121 | content stringlengths 0 2.2M |
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630bb3779e33ebc8586024227b48f59f | 103 973 | 5.2.23 num_bits_code() | Table 33: Syntax of num_bits_code() Syntax Encoding Clause num_bits_code() 6.1.20 { bits_code u(2) 6.1.20.1 num_bits = (bits_code + 1) × 8 return num_bits } |
630bb3779e33ebc8586024227b48f59f | 103 973 | 5.2.24 block_index_or_count_value() | Table 34: Syntax of block_index_or_count_value() Syntax Encoding Clause block_index_or_count_value() 6.1.21 { block_index_or_count u(8) 6.1.21.1 if (block_index_or_count == 0xFF) { block_index_or_count_ext u(32) 6.1.21.1 } else { block_index_or_count_ext = 0 6.1.21.1 } block_index_or_count_val = block_index_or_count + ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 5.2.25 multi_block_packet_group() | Table 35: Syntax of multi_block_packet_group() Syntax Encoding Clause multi_block_packet_group() 6.1.22 { mbpg_index u(16) 6.1.22.1 mbpg_start_block_index = block_index_or_count_value() 5.2.24, 6.1.22.2 mbpg_num_blocks = block_index_or_count_value() 5.2.24, 6.1.22.3 mbpg_num_symbols u(64) 6.1.22.4 mbpg_header() 5.2.26 ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 5.2.26 mbpg_header() | Table 36: Syntax of mbpg_header() Syntax Encoding Clause mbpg_header() 6.1.23 { mbpg_symbol_arrangement v(4) 6.1.23.1 reserved v(4) switch (mbpg_group_symbol_arrangement) { case 0: case 1: reserved v(4) mbpgsi_bits = num_bits_code() 5.2.23, 6.1.23.2 for (index=0; index < mbpg_num_symbols; index++) { mbpg_source_block_i... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6 Bitstream description | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.0 Introduction | This clause describes the meaning of the fields in the CMMF bitstream syntax. Bit fields that are similar in purpose and/or meaning have been grouped and described only once. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1 Description of bitstream elements | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.1 cmmf_bitstream() | The cmmf_bitstream() is the top-level structure containing the sync() and all subatom() instances for the encoded CMMF bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.2 subatom() | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.2.0 Introduction | The subatom (subatom()) is a generic structure that represents various types of data present in the CMMF bitstream. Subatoms inherit values from previously received subatoms with a matching bitstream_id (if present the bitstream). For example, the packet_header() structure should be able to use block_field_size_exp fie... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.2.1 subatom_id, subatom_id_ext | The subatom_id field, which is extendable by the subatom_id_ext field, identifies the type of data in contained within the subatom. This field indicates which syntactical structure is present in the subatom. Subatom identification values are provided in Table 37. Table 37: subatom_id meaning subatom_id value Associated... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.2.2 b_bitstream_id_present | This Boolean indicates whether the bitstream_id is present the bitstream. This bit shall be set to the same value in every subatom() instance in a cmmf_bitstream(). |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.2.3 sas_bits | The operational variable sas_bits is used in the syntax to specify the number of bits used to encode the subatom data and is represented by the num_bits_code() structure. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.2.4 bitstream_id | The bitstream_id field identifies different subatoms as belonging to the same bitstream. In applications where simultaneous bitstreams are transmitted, this identification enables a receiver/decoder to determine which subatoms belong to which bitstream. bitstream_id, if present in the bitstream, shall be set to the sam... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.2.5 subatom_size | The subatom_size field describes the size of the subatom data, in bytes. The subatom data is marked by the 'subatom data start' and 'subatom data end' labels. That is, the subatom data type as indicated by the subatom_id field, and any additional padding required to ensure that the subatom_size is a whole number of byt... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.3 sync() | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.3.0 Introduction | The synchronization (sync()) structure appears at the beginning of every bitstream and identifies the stream as being a CMMF bitstream. Depending on the application, the sync() structure can also be contained within a subatom() as needed in order to resynchronize in the middle of a stream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.3.1 syncword | The syncword field is a synchronization word used to identify a CMMF bitstream. The value of the syncword field shall be 0x89780D430044AC31. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 62 |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.3.2 version | The version field specifies the version of the CMMF bitstream syntax. Encoders conforming to the present document shall use a value of 0 for this field. Bitstream parsers conforming to the present document shall be able to parse version 0. Bitstream parsers conforming to the present document shall reject bitstreams wit... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.3.3 b_content_encode_uuid | This Boolean indicates whether the content_encode_uuid field is present in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.3.4 content_encode_uuid | The content_encode_uuid field identifies a specific encode of a piece of content. This field should carry a version 4, variant 1 universally unique identifier as specified in IETF RFC 9562 [1]. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4 bitstream_header() | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.0 Introduction | The bitstream header (bitstream_header()) structure contains high-level general file information about the encoded data and encoding method. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.1 content_source_size | The content_source_size field describes the size of the source data, in bytes. If the source data exceeds the size practical for an application, the source data can be split, and multiple bitstreams used. If the content_source_size field is zero, it indicates the source data has a size of 0 bytes, or the size of the so... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.2 content_source_type | The content_source_type field describes the source of the encoded data within the bitstream as listed in Table 39. Table 39: content_source_type meaning content_source_type value Meaning 000b Not indicated 001b Original data file 010b Reserved 011b Live streaming source 100b-111b Reserved |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.3 b_content_source_split | This Boolean indicates whether the source data has been split and carried in multiple bitstreams. When True, the content_source_split_start and content_source_split_end fields are present in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.4 content_soure_split_start, content_source_split_end | The content_source_split_start and content_source_split_end fields describe the start and end byte range of the original source data that is carried in the bitstream. A parser can use this information to reassemble the original source data. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 63 |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.5 code_type, code_type_ext | The code_type field, which is extendable by the code_type_ext field, identifies the type of code applied to the data in the bitstream. The different coding types are listed in Table 40. Client rendering devices shall support decoding a minimum of one of the supported code types. Table 40: code_type meaning code _type v... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.6 b_rfc5052, rfc5052_information(), b_addl_rfc5052_information_present | This Boolean indicates that CMMF is used as a Content Delivery Protocol (CDP) as defined in IETF RFC 5052 [15]. When True, data shall be partitioned according to the algorithm described in section 9.1 of IETF RFC 5052 [15], and the additional fields contained within the rfc5052_information() structure that describe the... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.7 block_count_minus1, block_count | The operational variable block_count_minus1 which is represented by the block_index_or_count_value() structure, describes the total number of blocks present in the bitstream, minus one. The operational variable block_count is used throughout the syntax and is calculated as follows: block_count = block_count_minus1 + 1 ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.8 b_content_block_separate_sources | This Boolean indicates whether blocks contain data from separate (but possibly related) sources. For example, block 0 may contain a video segment, while block 1 may contain an audio segment for the same content. When this field is TRUE the num_content_block_sources_minus1 field is present in the bitstream. An individua... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.9 num_content_block_sources_minus1 | num_content_block_sources_minus1 describes the number of sources of data that populate the blocks in the bitstream, minus one. The number of sources shall be less than or equal to the number of blocks (indicated by the block_count variable) present in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.10 b_profile_information_present | This Boolean indicates whether information about the profile that this bitstream conforms to, as indicated by the profile_type_size, profile_type, and profile_description fields, is present in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.11 profile_type_size, profile_type | The profile_type field is a string of ASCII [7] or UTF-8 [11] characters describing the entity defining the profile. The size (in bytes) of the profile_type field is indicated by the profile_type_size field. profile_type shall not be set to a value of 0. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.12 profile_description | The profile_description field identifies the profile which the bitstream conforms to, as defined by the entity indicated by the profile_type field. A profile may impose constraints on the coding type used, number of blocks, number of symbols or other encoding parameters. Determining whether a bitstream conforms to a sp... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.13 b_block_cc_encrypted | This Boolean indicates whether the coding coefficient information in one or more blocks is encrypted. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 65 In this case, the bitstream_encryption_key_id_size_exp and bitstream_encryption_key_id fields are present in the bitstream. The bitstream_encryption_key_id can then be used to r... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.14 bitstream_encryption_key_id_size_exp | The bitstream_encryption_key_id_size_exp field contains the exponent used to determine the size (in bits) used to transmit the subsequent bitstream_encryption_key_id. The size is given by the following equation: bseki_bits = 2^ bitstream_encryption_key_id_size_exp |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.4.15 bitstream_encryption_key_id | The bitstream_encryption_key_id field identifies the key used to symmetrically encrypt certain block encryption parameters. The identification can be a simple numeric identifier, or for example, a hash of the key. The encryption method is outside the scope of the present document. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5 block_header() | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.0 Introduction | The block header (block_header()) structure provides information about how the portion of the data within that block is encoded. It contains fields that describe the coding parameters used for the indicated block. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.1 block_index | The operational variable block_index, which is represented by the block_index_or_count_value() structure, describes which block this block_header() instance is associated with. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.2 block_size | The block_size field describes the number of bytes from the original data the block contains. A block_size value of 0 may be used to indicate that the block size is either not relevant, or the block is empty, or the size is undetermined. A block_size value of 0 shall only be used when block_count is 1. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.3 block_symbol_size | The block_symbol_size field describes the size in bytes of each symbol and coded symbol in the block. A block_symbol_size value of 0 is used to indicate that the coded symbols in the block have a varying size, and the size shall be determined by other means. The block_symbol_size shall not have a value of 0 when packet... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.4 bns_bits | The operational variable bns_bits is used in the syntax to specify the number of bits used to encode the block_num_symbols field and is represented by the num_bits_code() structure. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.5 block_num_symbols | The block_num_symbols field describes the number of symbols that the original block of data has been divided into. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 66 A block_num_symbols value of 0 may be used to indicate that the block has an unknown number of symbols. A block_num_symbols value of 0 shall only be used when block... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.6 b_block_max_symbol_index_present | This Boolean indicates whether the maximum encoded symbol index (or row index) value for the given block is present in the bitstream. When TRUE, the block_max_symbol_index field is present in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.7 bmsi_bits | The operational variable bmsi_bits is used in the syntax to specify the number of bits used to encode the block_max_symbol_index field and is represented by the num_bits_code() structure. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.8 block_max_symbol_index | The block_max_symbol_index field identifies either the value of the maximum symbol index when encoded symbol indexes are used to identify coded symbols, or the value of the maximum row index when a pseudo-random number generator is used to determine the coding coefficients for the block. For example, if a block contain... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.9 b_block_content_source_index_present | This Boolean indicates whether the given block contains data from a different source than the other blocks present in the bitstream. When TRUE, the block_content_source_index field is present in the bitstream. If the b_block_content_separate_sources field in the bitstream_header() is TRUE, then b_block_content_source_i... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.10 block_content_source_index | The block_content_source_index field identifies which source, of the num_content_block_sources the data in this block is associated with. The field has a range of [0, num_content_block_sources - 1]. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.11 b_block_composite_sources | This Boolean indicates whether the given block contains composite data from multiple different sources. The b_block_composite_sources field indicates whether additional fields that describe the number and size of each composite source are present in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.12 block_num_composite_sources_minus1 | The block_num_composite_sources_minus1 field describes the number of composite sources that make up the data contained within the block, minus 1. The field has a range of [1, 256]. For each composite source, there will be an instance of num_bits_code() and the block_composite_source_size field in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.13 bcss_bits | The operational variable bcss_bits contains the number of bits the subsequent related field requires and is represented by the num_bits_code() structure. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.14 block_composite_source_size | The block_composite_source_size field describes the size of the composite source data, in bytes, that is present within the block. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 67 |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.15 b_addl_block_coding_info_present | This Boolean indicates whether additional information describing the coding used in the given block follows in the bitstream. Otherwise, no sliding window is used and the coding information is described by other fields in the bitstream (e.g. code_type, block_mask). |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.16 addl_block_coding_mask | The addl_block_coding_mask field is a bit mask that describes additional coding information and indicates which subsequent fields are present in the bitstream as specified in Table 42. Table 42: addl_block_coding_mask meaning addl_block_coding_mask bit Meaning 0 Sliding window coding used: This bit indicates whether a ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.17 b_addl_window_info_present | This Boolean indicates whether the addl_window_info() element follows. The addl_window_info() element is an instance of the extension() structure. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.18 b_reserved_block_coding_params_present | This Boolean indicates whether the reserved_block_coding_params() element follows. The reserved_block_coding_params() element is an instance of the extension() structure, and shall be ignored by bitstream parsers that conform to this version of CMMF. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.19 block_mask | The block_mask field is an array of Booleans that indicates which subsequent fields are present and follow in the bitstream as listed in Table 43. Table 43: block_mask meaning block_mask bit Meaning 0 Sufficient symbols present: This Boolean indicates whether fields describing the number of encoded symbols contained wi... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.20 b_sufficient_symbols_present | This Boolean indicates whether a sufficient number of encoded symbols (greater than or equal to block_num_symbols) are present in the bitstream to decode the current block. Otherwise, the block_symbols_present field is present in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.21 bsp_bits | The operational variable bsp_bits is used in the syntax to specify the number of bits used to encode the block_symbols_present field and is represented by the num_bits_code() structure. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.22 block_symbols_present | The block_symbols_present field describes the number of encoded symbols present within the bitstream associated with the current block. In a multisource network there may be multiple CMMF bitstreams, with some bitstreams containing a sufficient number of encoded symbols to decode the current block and others with only ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.23 block_field_size_exp | If block_field_size_exp is present in the bitstream, coding coefficients are used to create encoded symbols. These coefficients come from a finite field set, a Galois field. The size of this Galois field is given by a characteristic prime, 2 in this case, and an exponent. This determines the number of possible coding c... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24 Encrypted Coefficients | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.0 Introduction | When bit 3 of the block_mask field is set, the coding coefficient information in the bitstream is encrypted. The coding coefficient information can be any of: • prng_seed and prng_density_percentage within prng_parameters() in block_header(). • coefficient_vector() in packet_header() within the packet subatom or the pa... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.1 block_cc_encryption_info_size_bits_code | The block_cc_encryption_info_size_bits_code field describes the number of bits used to describe the size of the block encryption information size (indicated by the block_cc_encryption_info_size field). The meaning of this field is specified in Table 45. Table 45: block_cc_encryption_info_size_bits_code meaning block_cc... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.2 byte_align | This bit field of size 0 to 7 bits is used for the byte alignment of the associated block_header() structure. Byte alignment is defined relative to the start of the enclosing syntactic element. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.3 block_cc_encryption_info_size | The block_cc_encryption_info_size field describes the size of the block encryption information data, in bytes. The data comprises of several fields and is marked by the 'block encryption info start' and 'block encryption info end' labels including any additional padding required to ensure that the block_cc_encrypton_in... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.4 block_cc_encryption_algorithm | block_cc_encryption_algorithm specifies the algorithm used to encrypt the coding coefficient information. The different algorithm types are listed in Table 46. Table 46: block_cc_encryption_algorithm meaning block_cc_encryption_algorithm Value Meaning 000b AES 001b-111b Reserved |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.5 block_cc_encryption_mode | block_cc_encryption_mode specifies the mode of chaining operation used to encrypt the coding coefficient information. The different algorithm types are listed in Table 47. Table 47: block_cc_encryption_mode meaning block_cc_encryption_mode Value Meaning 0000b Electronic Code Book (ECB) 0001b Cipher Block Chaining (CBC)... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.6 block_cce_key_size_exp, block_cce_key | block_cce_key is the symmetric key used to encrypt the coding coefficient information. The key size (in bits) of the block_cce_key field is indicated by the block_cce_key_size_exp field according to the equation: bck_bits = 2 ^ block_cce_key_size_exp ETSI ETSI TS 103 973 V1.2.1 (2026-03) 71 |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.7 b_addl_block_cce_params_present | This Boolean indicates whether additional encryption parameters required to decrypt the coding coefficient information, contained in the addl_cce_parameters() structure, follow in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.24.8 addl_cce_parameters() | 6.1.5.24.8.0 Introduction The addl_cce_parameters() structure contains additional encryption parameters. The context of addl_cce_parameters() is defined by the containing block_header(), packet_header(), or packet_group_header() structure. 6.1.5.24.8.1 num_addl_block_cce_params_minus1 num_addl_block_cce_params_minus1 d... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.25 Pseudorandom Noise Generator (PRNG) | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.25.0 Introduction | A PRNG is used to generate coding coefficients that are applied to source symbols to create encoded symbols. The generated coefficients can be transmitted verbatim in the bitstream, or the state of the PRNG, known as the seed, can be transmitted and a decoder can regenerate the same coding coefficient matrix calculated... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.25.1 prng_type | prng_type specifies the type of number generator to use to generate the coding coefficient(s) for the given block or packet. The different prng types are listed in Table 49. Table 49: block_prng_type meaning block_prng_type Value Meaning 000b Mersenne Twister (MT) [8] 001b-111b Reserved |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.25.2 prng_seed_bits_code | The prng_seed_bits_code field describes the number of bits the prng_seed field is encoded with as indicated in Table 50. Table 50: block_prng_seed_bits_code meaning prng_seed_bits_code value Meaning 0 16 bits 1 32 bits 2 64 bits 3 Reserved The operational variable ps_bits uses the prng_seed_bits_code value to determine... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.25.3 prng_seed | prng_seed specifies the seed value used to initialize the PRNG for generating coefficients for the block or packet. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 73 |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.5.25.4 prng_density_percentage | prng_density_percentage describes the percentage of coding coefficients that are, on average, non-zero. The field is encoded as a fraction in range (0, 1] and the actual percentage is determined by the following equation: density percentage = 100 × (prng_density_percentage + 1) / 128 An operational variable, density_in... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.6 packet() | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.6.0 Introduction | The packet (packet()) structure contains the packet_header(), as well as a coded symbol (an individual symbol group), which is a fundamental piece of encoded data. Packets, as well as other fields contained within larger structures, inherit values from previous subatom() instances. For example, the packet() structure i... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.6.1 packet_block_index | The operational variable packet_block_index, which is represented by the block_index_or_count_value() structure if block_count is greater than 1, describes which block this packet() (or packet_header_only()) instance is associated with. If the bitstream only contains a single block (i.e. block_count is 1), then the blo... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.6.2 coded_symbol | A coded_symbol is either a systematic symbol or the encoded version of a number of source symbols, generated by applying coding to the original data symbols. The size of this field is determined by the operational variable css_bits calculated using the following formula: css_bits = (subatom_size × 8) - sizeof(packet_bl... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7 packet_header() | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.0 Introduction | 6.1. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 7.0 Introduction | The packet_header() structure provides information about how the coded symbols were encoded. The packet_header() will be different depending on whether it is encapsulated in a packet subatom or in a packet header only subatom. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 74 |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.1 b_systematic_symbol | When True, this boolean indicates that the coded symbol in the packet is systematic (i.e. not coded). In this case, a symbol index is present in the bitstream so that the original source symbol can be identified and used to decode the other packets. When this field is False, no immediate indication is given that the co... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.2 packet_mask | The packet_mask field is an array of Booleans that describes which subsequent fields are present in the bitstream as listed in Table 51. Table 51: packet_mask meaning packet_mask bit Meaning 0 Symbol/row index present: This Boolean indicates whether index fields are present in the bitstream that identify the symbol or ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.3 psi_bits | The operational variable psi_bits is used in the syntax to specify the number of bits used to encode the packet_symbol_index field. psi_bits is represented by the num_bits_code() structure. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.4 packet_symbol_index | The packet_symbol_index field defines an index whose meaning is context dependent: • If the b_systematic_symbol is set, the packet_symbol_index value is the original symbol index number. • For certain code_type values, (e.g. 1 (RaptorQ) or 2 (Reed-Solomon)), the packet_symbol_index value represents the encoded symbol i... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.5 Encryption Parameters | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.5.0 Introduction | When bit 1 of the packet_mask field is set, additional encryption parameters needed to decrypt the coding coefficient information within the packet_header() are present in the bitstream. The coding coefficient information within the packet_header() can be any of: • coefficient_vector() in packet_header() within the pac... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.5.1 b_systematic_symbol_encrypted | This Boolean indicates whether the coded_symbol field is encrypted. This field can only be set if the b_systematic_symbol field is also set. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.5.2 b_addl_packet_cce_params_present | This Boolean indicates whether additional encryption parameters required to decrypt the coding coefficient information, contained in the addl_cce_parameters() structure, follow in the bitstream. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.6 window_start_index, window_stop_index | The window_start_index and window_stop_index fields indicate the index of the first symbol present in the coded symbol, the start index, and the index of the last symbol present in the coded symbol, the stop index, to form a window of contiguous symbols from amongst the total set of symbols contained within the block. ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.7.7 byte_align | This bit field of size 0 to 7 bits is used for the byte alignment of the associated packet_header() structure. Byte alignment is defined relative to the start of the enclosing syntactic element. |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.8 encoder_content_info() | |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.8.0 Introduction | The CMMF bitstream has applications in online delivery of audio/video content. The optional encoder content information (encoder_content_info()) structure contains information about the specific encoder utilized, and the source assets, such as a content identification. This subatom is useful when CMMF bitstreams for a ... |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.8.1 b_encoder_id_present | This Boolean indicates whether the encoder_uuid field is present the bitstream. ETSI ETSI TS 103 973 V1.2.1 (2026-03) 77 |
630bb3779e33ebc8586024227b48f59f | 103 973 | 6.1.8.2 encoder_uuid | The encoder_id field identifies the specific encoder used to create the bitstream. The field carries a version 4, variant 1 universally unique identifier as specified in IETF RFC 9562 [1]. This field enables efficient use of a plurality of encoders in decentralized settings. |
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