4. pmt class

이 장에서는 PMT (Program Map Table)에 대해서 알아보고, 구현 클래스를 살펴본다.

PMT의 주요목적은 ES (Element Stream)에 대한 PID를 얻어오는 것이다.

또한 각 ES의 Type을 확인할 수 있다. Type의 의미는 현재 ES가 Audio인지 아니면 Video인지

Video이면 MPEG-2, MPEG-4 Part 4, MPEG-4 Part 10 지금은 UHD를 위한 타입도 추가되었다.

Set-Top Box나 TV에서는 A/V Decoder 블록이 존재하고 PMT에서 추출한 ES에 대한

PID를 A/V Decoder에 잘 넘겨주는 것이 System Decoder단 작업의 일이라고 보면된다.

PMT PID에 PCR PID가 있는데 Adaptation Field에 존재하는 PCR PID와 어떤 상관관계가

있는지 기억이 나지 않는다.

Adaptation Field를 이용하여 PCR Recovery, Rate 등 세가지인가 만족해야 하는 조건이 있다.

전에 한번 짜봐서 확인해 봤는데 분석기와 동일한 결과가 나왔다.

기회가 되면 소스 정리해서 올려놔야겠다.

Stream Analyzer처럼 Stream Type을 보기 좋게 하기 위해서는 추가적인 작업이 많이

필요해서 그냥 hexa값으로 표시하는 정도로 마무리한다.

1. 소스 트리

.

├── CMakeLists.txt

├── pat.cpp

├── pat.h

├── pmt.cpp

├── pmt.h

├── psi_glob.h

├── remove.sh

├── section.cpp

├── section.h

├── test.cpp

└── types.h

2. 헤더 파일

PMT를 Parsing하기 위한 전제 조건은 PAT가 Parsing 완료되어야 한다. 따라서 PAT는 필수적으로

따라 다닌다고 보면 된다.

#ifndef __PMT_H__ #define __PMT_H__ #include <cstdio> #include <iostream> #include <memory> #include <forward_list> #include "types.h" #include "psi_glob.h" /* ------------------------------------------------------------------------------------------------------------------- declare define ------------------------------------------------------------------------------------------------------------------- */ #define _RESERVED 0x00 #define MPEG1_VIDEO 0x01 #define MPEG2_VIDEO 0x02 #define MPEG1_AUDIO 0x03 #define MPEG2_AUDIO 0x04 #define PRIVATE_SECTION 0x05 #define PES_PRIVATE_DATA 0x06 #define MHEG 0x07 #define DSMCC 0x08 #define MPEG4_VIDEO 0x10 #define MPEG4_H264_VIDEO 0x1B #define HEVC_VIDEO 0x24 //#define PRINT_PMT_SECSION_HEADERå #ifdef PRINT_PMT_SECSION_HEADER #define PRINT_PMT_INFO(x) std::printf("%30s = %10d [%#10x]\n", #x, x, x); #else #define PRINT_PMT_INFO(x) #endif /* ------------------------------------------------------------------------------------------------------------------- declare class data ------------------------------------------------------------------------------------------------------------------- */ typedef struct { UINT8 stream_type; UINT16 es_pid; } ES_INFO_T; typedef struct { UINT8 version; UINT8 section_number; UINT16 program_number; UINT16 pcr_pid; std::forward_list<ES_INFO_T> es_info; } PMT_INFO_T; class PMT { public : PMT(); ~PMT(); RESULT_T parsingPMTSection(UINT16 pmtPid, UINT8* pData); bool isExistPmt(UINT8 vserion_number, UINT8 section_number, UINT16 program_number); void addNewPMTtoList(PMT_INFO_T newPmt); void addNewEStoPMT(PMT_INFO_T newPmt, ES_INFO_T newEs); void printPMTList(void); UINT32 getPMTProgNum(void); private : UINT32 numProgs; std::forward_list<PMT_INFO_T> pmtList; }; #endif

3. 클래스 본체

/** This is free and unencumbered software released into the public domain. Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means. In jurisdictions that recognize copyright laws, the author or authors of this software dedicate any and all copyright interest in the software to the public domain. We make this dedication for the benefit of the public at large and to the detriment of our heirs and successors. We intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. For more information, please refer to <http://unlicense.org> */ /** -------------------------------------------------------------------- file : pmt.cpp parsing program map table informaiton version : 1.0 data : 2016.06.01 author : HeeSoon Kim(chipmaker0304@gmail.com) -----------------------------------------------------------------------*/ #include "pmt.h" PMT::PMT() { numProgs = 0; std::cout << __FUNCTION__ << std::endl; } PMT::~PMT() { for(auto list : pmtList) { list.es_info.clear(); } pmtList.clear(); std::cout << __FUNCTION__ << std::endl; } bool PMT::isExistPmt(UINT8 version_number, UINT8 section_number, UINT16 program_number) { for(auto list : pmtList) { if(list.version == version_number && list.section_number == section_number && list.program_number == program_number) { return true; } } return false; } UINT32 PMT::getPMTProgNum(void) { return numProgs; } void PMT::addNewPMTtoList(PMT_INFO_T newPmt) { pmtList.push_front(newPmt); } void PMT::addNewEStoPMT(PMT_INFO_T newPmt, ES_INFO_T newEs) { //pmtList.push_front(es_list); for(auto &pmt_list : pmtList) { if(pmt_list.program_number == newPmt.program_number) { pmt_list.es_info.push_front(newEs); } } } void PMT::printPMTList(void) { int i = 1; int j = 1; // sort by porgram number pmtList.sort([](PMT_INFO_T& prog1, PMT_INFO_T& prog2) -> bool { return prog1.program_number < prog2.program_number; }); for(auto list : pmtList) { std::printf("%3d] PMT version = %2d Section = %2d program_number = %3d [PCR PID %5d (%#5x)]\n" \ , i, list.version, list.section_number, list.program_number, list.pcr_pid, list.pcr_pid); for(auto es_list : list.es_info) { std::printf(" -> [%3d] stream_type = %#5x [ES PID %5d (%#5x)]\n" \ , j, es_list.stream_type, es_list.es_pid, es_list.es_pid); j++; } i++; j = 1; } } RESULT_T PMT::parsingPMTSection(UINT16 pmtPid, UINT8 *pData) { UINT8 *pSection; UINT8 point_field; UINT8 table_id; UINT16 section_length; UINT16 program_number; UINT8 version_number; bool current_next_indicator; UINT8 section_number; UINT8 last_section_number; UINT16 PCR_PID; UINT16 program_info_length; UINT8 stream_type; UINT16 elementary_PID; UINT16 ES_info_length; UINT32 descriptor_length; PMT_INFO_T pmt_info; ES_INFO_T es_info; point_field = pData[0]; //PRINT_PMT_INFO(point_field); pSection = pData + point_field + 1; table_id = pSection[0]; //PRINT_PMT_INFO(table_id); section_length = ((pSection[1] & 0x0f) << 8) | pSection[2]; PRINT_PMT_INFO(section_length); program_number = (pSection[3] << 8) | pSection[4]; //PRINT_PMT_INFO(program_number); version_number = (pSection[5] >> 0x01) & 0x1f; //PRINT_PMT_INFO(version_number); current_next_indicator = pSection[5] & 0x01; //PRINT_PMT_INFO(current_next_indicator); section_number = pSection[6]; //PRINT_PMT_INFO(section_number); last_section_number = pSection[7]; //PRINT_PMT_INFO(last_section_number); PCR_PID = ((pSection[8] & 0x1f) << 8) | pSection[9]; PRINT_PMT_INFO(PCR_PID); program_info_length = ((pSection[10] & 0x0f) << 8) | pSection[11]; PRINT_PMT_INFO(program_info_length); pSection = pData + point_field + PMT_HEADER_SIZE + program_info_length + 1; section_length -= PMT_HEADER_SIZE + 1 + program_info_length; if(isExistPmt(version_number, section_number, program_number) == true) { return RESULT_NOTOK; } // add new PMT to list pmt_info.version = version_number; pmt_info.section_number = section_number; pmt_info.program_number = program_number; pmt_info.pcr_pid = PCR_PID; numProgs++; addNewPMTtoList(pmt_info); while(section_length > 0) { stream_type = pSection[0]; PRINT_PMT_INFO(stream_type); elementary_PID = ((pSection[1] & 0x1f) << 8) | pSection[2]; PRINT_PMT_INFO(elementary_PID); ES_info_length = ((pSection[3] & 0x0f) << 8) | pSection[4]; PRINT_PMT_INFO(ES_info_length); es_info.stream_type = stream_type; es_info.es_pid = elementary_PID; addNewEStoPMT(pmt_info, es_info); if(ES_info_length+5 > section_length) break; pSection += 5; section_length -= (ES_info_length + 5); while(ES_info_length > 0) { // Parsing Descriptor descriptor_length = pSection[1] + 2; if(descriptor_length > ES_info_length) { pSection += ES_info_length; ES_info_length = 0; break; } ES_info_length -= descriptor_length; pSection += descriptor_length; } } return RESULT_OK; }

4. 테스트 코드

#include <thread> #include "section.h" #include "pat.h" #include "pmt.h" int main(int argc, char* argv[]) { SECTION_INFO_T sec; CSection* section = new CSection(); PAT* pat = new PAT(); PMT* pmt = new PMT(); // open media test, media is file section->openMedia("file://SGP.ts"); // create task to read continously std::thread tr = std::thread([&]() { while(1) { if(section->readMedia(&sec) == RESULT_NOTOK) break; // PAT parsing PAT PID is zero if(sec.pid == 0) { pat->parsingPATSection((UINT8*)sec.section); } else if(pat->isPmtPid(sec.pid) == true) { // current pid is pmt pid pmt->parsingPMTSection(sec.pid, (UINT8*)sec.section); } } }); tr.join(); // print PAT info pat->printPATList(); pmt->printPMTList(); delete section; delete pat; delete pmt; return 0; }

5. 실행 결과 

hskim@MacBookPro/Volumes/Macintosh HD 2/share/c++/pmt $./test CSection pat generator called !!  PMT current media type : FILE  mediaInPath : SGP.ts No Data !!    1] PAT version =  1 Section =  0 program_number = 208 [PID  1031 (0x407)]   2] PAT version =  1 Section =  0 program_number = 209 [PID  1032 (0x408)]   3] PAT version =  1 Section =  0 program_number = 210 [PID  1033 (0x409)]   4] PAT version =  1 Section =  0 program_number = 211 [PID  1034 (0x40a)]   5] PAT version =  1 Section =  0 program_number = 212 [PID  1035 (0x40b)]   6] PAT version =  1 Section =  0 program_number = 213 [PID  1036 (0x40c)]   1] PMT version =  1 Section =  0 program_number = 208 [PCR PID   260 (0x104)]   -> [  1] stream_type =  0x11 [ES PID   515 (0x203)]   -> [  2] stream_type =  0x11 [ES PID   514 (0x202)]   -> [  3] stream_type =  0x11 [ES PID   513 (0x201)]   -> [  4] stream_type =  0x11 [ES PID   516 (0x204)]   -> [  5] stream_type =  0x1b [ES PID   260 (0x104)]   -> [  6] stream_type =   0x6 [ES PID   103 ( 0x67)]   -> [  7] stream_type =   0x6 [ES PID   102 ( 0x66)]   -> [  8] stream_type =   0x6 [ES PID   101 ( 0x65)]   -> [  9] stream_type =   0x6 [ES PID   100 ( 0x64)]   2] PMT version =  1 Section =  0 program_number = 209 [PCR PID   259 (0x103)]   -> [  1] stream_type =  0x11 [ES PID   517 (0x205)]   -> [  2] stream_type =  0x11 [ES PID   513 (0x201)]   -> [  3] stream_type =  0x11 [ES PID   516 (0x204)]   -> [  4] stream_type =  0x1b [ES PID   259 (0x103)]   3] PMT version =  1 Section =  0 program_number = 210 [PCR PID   257 (0x101)]   -> [  1] stream_type =  0x11 [ES PID   513 (0x201)]   -> [  2] stream_type =   0x6 [ES PID   100 ( 0x64)]   -> [  3] stream_type =  0x11 [ES PID   516 (0x204)]   -> [  4] stream_type =  0x1b [ES PID   257 (0x101)]   4] PMT version =  1 Section =  0 program_number = 211 [PCR PID   258 (0x102)]   -> [  1] stream_type =  0x11 [ES PID   514 (0x202)]   -> [  2] stream_type =  0x11 [ES PID   517 (0x205)]   -> [  3] stream_type =   0x6 [ES PID   102 ( 0x66)]   -> [  4] stream_type =  0x11 [ES PID   514 (0x202)]   -> [  5] stream_type =  0x1b [ES PID   258 (0x102)]   5] PMT version =  1 Section =  0 program_number = 212 [PCR PID   514 (0x202)]   -> [  1] stream_type =  0x11 [ES PID   516 (0x204)]   -> [  2] stream_type =  0x11 [ES PID   514 (0x202)]   6] PMT version =  1 Section =  0 program_number = 213 [PCR PID   516 (0x204)]   -> [  1] stream_type =  0x11 [ES PID   516 (0x204)] ~CSection pat destroy called !!  ~PMT

6. 전체 소스 (github link)

https://github.com/heesoon/mpeg/tree/master/test/pmt