{"id":5761,"date":"2026-05-24T18:36:17","date_gmt":"2026-05-24T09:36:17","guid":{"rendered":"https:\/\/www.freelifemakers.org\/wordpress\/?p=5761"},"modified":"2026-05-24T18:41:15","modified_gmt":"2026-05-24T09:41:15","slug":"mediaserve-rmini_mediaserver_1-code-description-read_message_header1-4","status":"publish","type":"post","link":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/2026\/05\/24\/mediaserve-rmini_mediaserver_1-code-description-read_message_header1-4\/","title":{"rendered":"[Mediaserver]mini_Mediaserver_1-\ucf54\ub4dc\uc124\uba85\/code description-read_message_header()(1-4)"},"content":{"rendered":"\n

\ud83d\udc49\ud83c\udffb \uc5ec\uae30\ub294 void RtmpSession::read_message_header(uint8_t fmt, uint32_t cs_id) { } \uc774 \ud568\uc218\uc5d0 \ub300\ud55c \uc124\uba85\uc785\ub2c8\ub2e4.
Here is the description for the function void RtmpSession::read_message_header(uint8_t fmt, uint32_t cs_id) { }.<\/p>\n\n\n\n

\ud83d\udc49\ud83c\udffb OBS\uac00 \ubcf4\ub0b8 chunk\uc5d0\uc11c fmt 0\u223c3\uc5d0 \ub530\ub77c \uac00\ubcc0 \ud5e4\ub354\ub97c \uc77d\uace0, \ud604\uc7ac \uba54\uc2dc\uc9c0\uc758 timestamp, length, type, stream_id\ub97c \uac31\uc2e0\ud569\ub2c8\ub2e4.
Read variable headers according to fmt 0~3 from the chunk sent by OBS, and update the timestamp, length, type, and stream_id of the current message.<\/p>\n\n\n\n

\ud83d\udc49\ud83c\udffb \uac31\uc2e0\uc774\ub780 \uc758\ubbf8\ub294 “\uba64\ubc84\ubcc0\uc218 4\uac1c\ub97c \ub2e4\uc74c chunk \ud5e4\ub354\uc5d0\uc11c \uc77d\uc740 \uac12\uc73c\ub85c \ubc14\uafb8\uac70\ub098, delta(\ubcc0\ud654\uac12)\ub97c \ub354\ud574\uc11c \ub2e4\uc74c \uba54\uc2dc\uc9c0\ub97c \uc870\ub9bd\ud560 \uc900\ube44\ub97c \ud55c\ub2e4”\ub294 \ub73b\uc785\ub2c8\ub2e4.
Update means “prepare to assemble the next message by changing the four member variables to the values \u200b\u200bread from the next chunk header or adding delta(change value).”<\/p>\n\n\n\n

\n\n\n\n

\ud83d\udc49\ud83c\udffb 2\ube44\ud2b8\ub85c \ud45c\ud604 \uac00\ub2a5\ud55c \uac12 = 00, 01, 10, 11<\/code> = 10\uc9c4\uc218\ub85c 0, 1, 2, 3. \uae4c\uc9c0 \uac00\ub2a5\ud569\ub2c8\ub2e4.
Values \u200b\u200bthat can be represented by 2 bits = 00, 01, 10, 11 = up to 0, 1, 2, 3 in decimal.<\/p>\n\n\n\n

\ud83d\udc49\ud83c\udffb \ub124\ud2b8\uc6cc\ud06c\ub85c \ub370\uc774\ud130 \ubcf4\ub0b4\uae30(0x12345678)
Send data over network (0x12345678)<\/p>\n\n\n\n

\u2714\ufe0f 1\ubc14\uc774\ud2b8\uc529 \ubcf4\ub0bc \ub54c
When sending 1 byte at a time<\/p>\n\n\n\n

— \ub124\ud2b8\uc6cc\ud06c\ub85c \ubcf4\ub0bc \ub550 \ubb34\uc870\uac74 uint8_t<\/code> \ubc30\uc5f4, \uc989 \ubc14\uc774\ud2b8 \ub2e8\uc704\ub85c \ubcf4\ub0b4\uc57c \ud569\ub2c8\ub2e4.
When sending over a network, you must always send it as a uint8_t array, that is, in byte units.<\/p>\n\n\n\n

uint8_t buf[4] = {0x12, 0x34, 0x56, 0x78};\nsend(socket, buf, 4); \/\/ 1\ubc14\uc774\ud2b8\uc529 4\ubc88 \uc804\uc1a1\ub428 \/ Transmitted 4 times, 1 byte at a time<\/code><\/pre>\n\n\n\n
\u2714\ufe0f 2\ubc14\uc774\ud2b8\uc529 \ubcf4\ub0bc\ub54c(\ucd94\ucc9c\ud558\uc9c0 \uc54a\uc74c)
When sending 2 bytes at a time (not recommended)<\/p>\n\n\n\n
uint16_t buf[2] = {htons(0x1234), htons(0x5678)};\nsend(socket, buf, 4); \/\/ 12 34 56 78<\/code><\/pre>\n\n\n\n
\ud83d\udc49\ud83c\udffb1\ubc14\uc774\ud2b8\ub97c \uc77d\ub294 \ub2e4\ub294 \uc758\ubbf8\ub294 \uc18c\ucf13 \ubc84\ud37c\uc5d0 \ub4e4\uc5b4\uc628 \uc2e4\uc81c \ub370\uc774\ud130(\uc22b\uc790)\ub97c \uc77d\ub294 \ub2e4\ub294 \ub73b\uc785\ub2c8\ub2e4.(\ud3ec\uc778\ud130 \uc8fc\uc18c\ub791 \uad00\ub828 \uc5c6\uc74c)
Reading 1 byte means reading the actual data (number) that has entered the socket buffer. (It is not related to pointer addresses.)<\/p>\n\n\n\n
\n\n\n\n
\ud83d\udc49\ud83c\udffb fmt \uac12\uc5d0 \ub530\ub978 \ud5e4\ub4dc\ud06c\uae30 \uc124\uc815 \uc815\ubcf4\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.
The head size setting information based on the fmt value is as follows.<\/p>\n\n\n\n
\u2714\ufe0f \ud5e4\ub354 \ud06c\uae30, \ubcf4\ub0b4\ub294 \uc815\ubcf4
Header size, information being sent<\/p>\n\n\n\n
— msg_len\uc740 \uc2e4\uc81c\ub85c \ubcf4\ub0b4\uc9c0\ub294 \ub3d9\uc601\uc0c1 \ub370\uc774\ud130 \ud06c\uae30 \uc785\ub2c8\ub2e4.
msg_len is the actual size of the video data being sent.<\/p>\n\n\n\n
fmt<\/th>\uc774\ub984
name<\/th>		\ud5e4\ub354 \ud06c\uae30header size<\/th>\uc0ac\uc6a9\ud560\ub54c
When to use<\/th>		\ubcf4\ub0b4\ub294 \uc815\ubcf4
Sending information<\/th><\/tr><\/thead>
0<\/td>Type 0<\/td>11 byte<\/td>\uc0c8 \uba54\uc2dc\uc9c0 \uc2dc\uc791
Start a new message<\/td>		timestamp 3Byte 
+ msg_len 3B
+ msg_type 1B 
+ stream_id 4B<\/td><\/tr>
1<\/td>Type 1<\/td>7 byte<\/td>\uac19\uc740 stream_id, \ud0c0\uc785\ub9cc \uc774\uc5b4\uc11c \ubcf4\ub0bc \ub54c
When concatenating only stream_id and type<\/td>		timestamp_delta(\ucc28\uc774\uac12\/difference value) 3B 
+ msg_len 3B + msg_type 1B<\/td><\/tr>
2<\/td>Type 2<\/td>3 byte<\/td>msg_len, type \ub2e4 \uac19\uace0 \uc2dc\uac04\ub9cc \ubc14\ub014 \ub54c
When msg_len and type are the same and only the time changes<\/td>		timestamp_delta(\ucc28\uc774\uac12\/diffrence value) 3B<\/td><\/tr>
3<\/td>Type 3<\/td>0 byte<\/td>\ud5e4\ub354 \uc804\ubd80 \uc774\uc804\uc774\ub791 \uac19\uc744 \ub54c
When all headers are the same as before<\/td>		\uc544\ubb34\uac83\ub3c4 \uc5c6\uc74c
nothing<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u2714\ufe0f \ud5e4\ub354 \ubc30\uc5f4 \/ header array<\/p>\n\n\n\n
fmt<\/th>\ud5e4\ub354 \ubc14\uc774\ud2b8 \ubc30\uc5f4 \/ header byte array<\/th><\/tr><\/thead>
0<\/td>[TS0][TS1][TS2][Len0][Len1][Len2][Type][StreamID0\u223c3]<\/code> = 11B<\/td><\/tr>
1<\/td>[TS0][TS1][TS2][Len0][Len1][Len2][Type]<\/code> = 7B<\/td><\/tr>
2<\/td>[TS0][TS1][TS2]<\/code> = 3B<\/td><\/tr>
3<\/td>\uc5c6\uc74c<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u2714\ufe0f \ud328\ud0b7\uc5d0\uc11c \uac12\uc744 \ud655\uc778 \ud560\ub54c \ud5e4\ub354\ub2e4\uc74c\uc5d0 \ubcf8\ubb38(payload)\uc774 \uc635\ub2c8\ub2e4. \ubcf8\ubb38\uc758 \uacbd\uacc4\ub97c \ud655\uc778\ud558\uae30 \uc704\ud574\uc11c \ud5e4\ub354\uc758 \ud06c\uae30\ub97c \uc54c\uc544\uc57c\ud560 \ud544\uc694\uac00 \uc788\uc2b5\ub2c8\ub2e4.
When checking values \u200b\u200bin a packet, the body (payload) follows the header. To check the boundaries of the body, it is necessary to know the size of the header.<\/p>\n\n\n\n
\u2714\ufe0f \ud5e4\ub354\uc0ac\uc774\uc988\uac00 0\uc774\uba74 read_chunk_data()\ub97c \uc2e4\ud589\ud569\ub2c8\ub2e4.
If header size is 0, execute read_chunk_data().<\/p>\n\n\n\n
    size_t header_size = (fmt == 0)? 11 : (fmt == 1)? 7 : (fmt == 2)? 3 : 0;\n    if (header_size == 0) {\n        read_chunk_data();\n        return;\n    }<\/code><\/pre>\n\n\n\n
\u2714\ufe0f \ud5e4\ub354\uc5d0 \ubcc0\ud654\uac00 \uc788\ub294 \uacbd\uc6b0,\ud0c0\uc784\uc2a4\ud0ec\ud504 \uc870\ub9bd
If there is a change in the header, timestamp assembly<\/p>\n\n\n\n
— \uadf8\ub0e5 [0],[1],[2]\ub294 \uc790\ub9bf\uc218\uac00 \uacb9\uce58\uc9c0 \uc54a\uc73c\ubbc0\ub85c or \uc5f0\uc0b0\ud558\uba74 \uadf8\ub300\ub85c \ub0b4\ub824\uc635\ub2c8\ub2e4.
Since [0], [1], and [2] do not have overlapping digits, they come down as they are when performing an OR operation.<\/p>\n\n\n\n
     if (fmt <= 2) {\n         \/\/ | \ub294 or\uc5f0\uc0b0 \ub458\uc911 \ud558\ub098\ub77c\ub3c4 1\uc774\uba74 1,\uc544\ub798\ub294 \uc14b\uc911 \ud558\ub098\ub77c\ub3c4 1\uc774\uba74 1\n         \/\/ | is the OR operation; if at least one of the pairs is 1, the result is 1. The one below is 1 if at least one of the three is 1.\n         timestamp = (msg_header_buf_[0] << 16) | \n                     (msg_header_buf_[1] << 8) |  \n                      msg_header_buf_[2];          \n                                                         \n     }<\/code><\/pre>\n\n\n\n
# 01 E2 40 3\ubc14\uc774\ud2b8\uac00 \ub4e4\uc5b4\uc654\uc744 \uacbd\uc6b0\n# 01 E2 40 If 3 bytes are received\n\nmsg_header_buf_[0] = 0x01 = 00000001 = 1\nmsg_header_buf_[1] = 0xE2 = 11100010 = 226\nmsg_header_buf_[2] = 0x40 = 01000000 = 64\n\n# \uc67c\ucabd\uc73c\ub85c 16\ube44\ud2b8 \ubc00\uae30\n# Shift 16 bits to the left\n(0x01 << 16) = 0x010000 = 00000001 00000000\n\n# \uc67c\ucabd\uc73c\ub85c 8\ube44\ud2b8 \ubc00\uae30\n# Shift 8 bits to the left\n(0xE2 << 8) = 0x00E200 = 00000000 11100010 00000000\n\n# \ube44\ud2b8\ubc00\uae30 \uc5c6\uc74c\n# No beet milling\n 0x40 = 0x000040 = 00000000 00000000 01000000\n\n-------------------------------- OR \uc5f0\uc0b0 \/ OR operation\n               0x01E240 = 00000001 11100010 01000000 = 123456<\/code><\/pre>\n\n\n\n
\u2714\ufe0f \uc0c8 \ub9e4\uc138\uc9c0 \uc2dc\uc791,\ud655\uc7a5 \ud0c0\uc784\uc2a4\ud15c\ud504 \uc0ac\uc6a9,\ub3d9\uc601\uc0c1 \ud06c\uae30
Start new message, use extended timestamp, video size<\/p>\n\n\n\n
— 0xFFFFFF = 16,777,215 3\ubc14\uc774\ud2b8\ub85c \ud45c\ud604 \uac00\ub2a5\ud55c \ucd5c\ub300\uac12\uc73c\ub85c \ud655\uc7a5 \ud0c0\uc784\uc2a4\ud0ed\ud504\ub97c \uc0ac\uc6a9\ud574\uc57c\ud568\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4.
0xFFFFFF = 16,777,215, the maximum value that can be represented by 3 bytes, meaning that an extended timestamp must be used.<\/p>\n\n\n\n
— \uc0c8 \uba54\uc138\uc9c0 \ud5e4\ub354 \/New message header:<\/p>\n\n\n\n
timestamp 3(0~2)Byte + msg_len 3(3~5)B + msg_type 1(6)B + extended timestamp 4(7~10)B + stream_id 4B<\/code><\/pre>\n\n\n\n
— msg_len\uc740 \uc774\ubc88\uc5d0 \ubcf4\ub0bc FLV tag\/Video frame\/Audio packet \uc804\uccb4 \ud06c\uae30\uc785\ub2c8\ub2e4.
msg_len is the total size of the FLV tag\/Video frame\/Audio packet to be sent this time.<\/p>\n\n\n\n
— cur_msg_stream_ \ub294 stream_id\ub85c little endian\uc73c\ub85c \ubcc0\ud658\ud569\ub2c8\ub2e4.
cur_msg_stream_ converts to little endian with stream_id.<\/p>\n\n\n\n
 if (fmt == 0) {\n\n     cur_msg_timestamp_ = timestamp;\n     \/\/ 0xFFFFFF = 16,777,215 3\ubc14\uc774\ud2b8\ub85c\ud45c\ud604\uac00\ub2a5\ud55c \ucd5c\ub300\uac12,\n     \/\/ 0xFFFFFF = 16,777,215, the maximum value that can be represented by 3 bytes\n     \/\/ \ud655\uc7a5\ud544\ub4dc \/ extended field\n     if (timestamp == 0xFFFFFF && header_size >= 11) {\n        \/\/ use extended timestamp\n        cur_msg_timestamp_ = (msg_header_buf_[7] << 24) |\n                             (msg_header_buf_[8] << 16) |\n                             (msg_header_buf_[9] << 8) |\n                              msg_header_buf_[10];\n      }\n     \/\/ msg_len\n     cur_msg_len_ = (msg_header_buf_[3] << 16) | \n                    (msg_header_buf_[4] << 8) | msg_header_buf_[5];\n     \/\/ msg_type\n     cur_msg_type_ = msg_header_buf_[6];\n     \/\/ stream_id \n     \/\/ little endian\uc73c\ub85c \ubcc0\ud658\n     cur_msg_stream_ = msg_header_buf_[7] | \n                       (msg_header_buf_[8] << 8) |\n                       (msg_header_buf_[9] << 16) | \n                       (msg_header_buf_[10] << 24);\n     payload_buf_.clear();\n     payload_bytes_read_ = 0;<\/code><\/pre>\n\n\n\n
— stream_id\uac00 \ub3d9\uc77c\ud55c \uacbd\uc6b0,timestamp \ub204\uc801,\uae30\uc874 \uac12\uc740 \ub3d9\uc77c\ud569\ub2c8\ub2e4.
If stream_id is the same, timestamps accumulate, and existing values \u200b\u200bare identical.<\/p>\n\n\n\n
} else if (fmt == 1) {\n           \/\/ timestamp \ub204\uc801\n           \/\/ timestamp cumulative\n           cur_msg_timestamp_ += timestamp;\n\n           \/\/ msg_len\n           cur_msg_len_ = (msg_header_buf_[3] << 16) | \n                          (msg_header_buf_[4] << 8) | msg_header_buf_[5];\n           \/\/ msg_type\n           cur_msg_type_ = msg_header_buf_[6];\n           payload_buf_.clear();\n           payload_bytes_read_ = 0;\n\n           \/\/ \ub098\uba38\uc9c0\ub3d9\uc77c\ud558\uace0 \uc2dc\uac04\ub9cc \ubc14\ub00c\ub294 \uacbd\uc6b0\n           \/\/ Cases where everything else is the same and only the time changes\n} else if (fmt == 2) {\n            cur_msg_timestamp_ += timestamp;\n}<\/code><\/pre>\n\n\n\n
— read_chunk_data();\ub97c \uc2e4\ud589\ud569\ub2c8\ub2e4.
Execute read_chunk_data();<\/p>\n\n\n\n
Execute read_chunk_data();<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
\ud83d\udc49\ud83c\udffb \uc5ec\uae30\ub294 void RtmpSession::read_message_header(uint8_t fmt, uint32_t cs_id) { } \uc774 \ud568\uc218\uc5d0 \ub300\ud55c \uc124\uba85\uc785\ub2c8\ub2e4.Here is the description for the function void RtmpSession::read_message_header(uint8_t fmt, uint32_t cs_id) { }. \ud83d\udc49\ud83c\udffb OBS\uac00 \ubcf4\ub0b8 chunk\uc5d0\uc11c fmt 0\u223c3\uc5d0 \ub530\ub77c \uac00\ubcc0 \ud5e4\ub354\ub97c \uc77d\uace0, \ud604\uc7ac \uba54\uc2dc\uc9c0\uc758 timestamp, length, type, stream_id\ub97c \uac31\uc2e0\ud569\ub2c8\ub2e4.Read variable headers according to fmt 0~3 from the chunk sent by OBS, […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23,1],"tags":[],"class_list":["post-5761","post","type-post","status-publish","format-standard","hentry","category-cpp","category-uncategorized","missing-thumbnail"],"_links":{"self":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/5761","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/comments?post=5761"}],"version-history":[{"count":3,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/5761\/revisions"}],"predecessor-version":[{"id":5763,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/5761\/revisions\/5763"}],"wp:attachment":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/media?parent=5761"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/categories?post=5761"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/tags?post=5761"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}