?? mpeg2dec.c
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/* mpeg2dec.c, main(), initialization, option processing *//* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. *//* * Disclaimer of Warranty * * These software programs are available to the user without any license fee or * royalty on an "as is" basis. The MPEG Software Simulation Group disclaims * any and all warranties, whether express, implied, or statuary, including any * implied warranties or merchantability or of fitness for a particular * purpose. In no event shall the copyright-holder be liable for any * incidental, punitive, or consequential damages of any kind whatsoever * arising from the use of these programs. * * This disclaimer of warranty extends to the user of these programs and user's * customers, employees, agents, transferees, successors, and assigns. * * The MPEG Software Simulation Group does not represent or warrant that the * programs furnished hereunder are free of infringement of any third-party * patents. * * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware, * are subject to royalty fees to patent holders. Many of these patents are * general enough such that they are unavoidable regardless of implementation * design. * */#include <stdio.h>#include <stdlib.h>#include <ctype.h>#include <fcntl.h>#define GLOBAL#include "config.h"#include "global.h"/* private prototypes */static int video_sequence _ANSI_ARGS_((int *framenum));static int Decode_Bitstream _ANSI_ARGS_((void));static int Headers _ANSI_ARGS_((void));static void Initialize_Sequence _ANSI_ARGS_((void));static void Initialize_Decoder _ANSI_ARGS_((void));static void Deinitialize_Sequence _ANSI_ARGS_((void));static void Process_Options _ANSI_ARGS_((int argc, char *argv[]));#if OLDstatic int Get_Val _ANSI_ARGS_((char *argv[]));#endif/* #define DEBUG */static void Clear_Options();#ifdef DEBUGstatic void Print_Options();#endifint main(argc,argv)int argc;char *argv[];{ int ret, code; Clear_Options(); /* decode command line arguments */ Process_Options(argc,argv);#ifdef DEBUG Print_Options();#endif ld = &base; /* select base layer context */ /* open MPEG base layer bitstream file(s) */ /* NOTE: this is either a base layer stream or a spatial enhancement stream */ if ((base.Infile=open(Main_Bitstream_Filename,O_RDONLY|O_BINARY))<0) { fprintf(stderr,"Base layer input file %s not found\n", Main_Bitstream_Filename); exit(1); } if(base.Infile != 0) { Initialize_Buffer(); if(Show_Bits(8)==0x47) { sprintf(Error_Text,"Decoder currently does not parse transport streams\n"); Error(Error_Text); } next_start_code(); code = Show_Bits(32); switch(code) { case SEQUENCE_HEADER_CODE: break; case PACK_START_CODE: System_Stream_Flag = 1; case VIDEO_ELEMENTARY_STREAM: System_Stream_Flag = 1; break; default: sprintf(Error_Text,"Unable to recognize stream type\n"); Error(Error_Text); break; } lseek(base.Infile, 0l, 0); Initialize_Buffer(); } if(base.Infile!=0) { lseek(base.Infile, 0l, 0); } Initialize_Buffer(); if(Two_Streams) { ld = &enhan; /* select enhancement layer context */ if ((enhan.Infile = open(Enhancement_Layer_Bitstream_Filename,O_RDONLY|O_BINARY))<0) { sprintf(Error_Text,"enhancment layer bitstream file %s not found\n", Enhancement_Layer_Bitstream_Filename); Error(Error_Text); } Initialize_Buffer(); ld = &base; } Initialize_Decoder(); ret = Decode_Bitstream(); close(base.Infile); if (Two_Streams) close(enhan.Infile); return 0;}/* IMPLEMENTAION specific rouintes */static void Initialize_Decoder(){ int i; /* Clip table */ if (!(Clip=(unsigned char *)malloc(1024))) Error("Clip[] malloc failed\n"); Clip += 384; for (i=-384; i<640; i++) Clip[i] = (i<0) ? 0 : ((i>255) ? 255 : i); /* IDCT */ if (Reference_IDCT_Flag) Initialize_Reference_IDCT(); else Initialize_Fast_IDCT();}/* mostly IMPLEMENTAION specific rouintes */static void Initialize_Sequence(){ int cc, size; static int Table_6_20[3] = {6,8,12}; /* check scalability mode of enhancement layer */ if (Two_Streams && (enhan.scalable_mode!=SC_SNR) && (base.scalable_mode!=SC_DP)) Error("unsupported scalability mode\n"); /* force MPEG-1 parameters for proper decoder behavior */ /* see ISO/IEC 13818-2 section D.9.14 */ if (!base.MPEG2_Flag) { progressive_sequence = 1; progressive_frame = 1; picture_structure = FRAME_PICTURE; frame_pred_frame_dct = 1; chroma_format = CHROMA420; matrix_coefficients = 5; } /* round to nearest multiple of coded macroblocks */ /* ISO/IEC 13818-2 section 6.3.3 sequence_header() */ mb_width = (horizontal_size+15)/16; mb_height = (base.MPEG2_Flag && !progressive_sequence) ? 2*((vertical_size+31)/32) : (vertical_size+15)/16; Coded_Picture_Width = 16*mb_width; Coded_Picture_Height = 16*mb_height; /* ISO/IEC 13818-2 sections 6.1.1.8, 6.1.1.9, and 6.1.1.10 */ Chroma_Width = (chroma_format==CHROMA444) ? Coded_Picture_Width : Coded_Picture_Width>>1; Chroma_Height = (chroma_format!=CHROMA420) ? Coded_Picture_Height : Coded_Picture_Height>>1; /* derived based on Table 6-20 in ISO/IEC 13818-2 section 6.3.17 */ block_count = Table_6_20[chroma_format-1]; for (cc=0; cc<3; cc++) { if (cc==0) size = Coded_Picture_Width*Coded_Picture_Height; else size = Chroma_Width*Chroma_Height; if (!(backward_reference_frame[cc] = (unsigned char *)malloc(size))) Error("backward_reference_frame[] malloc failed\n"); if (!(forward_reference_frame[cc] = (unsigned char *)malloc(size))) Error("forward_reference_frame[] malloc failed\n"); if (!(auxframe[cc] = (unsigned char *)malloc(size))) Error("auxframe[] malloc failed\n"); if(Ersatz_Flag) if (!(substitute_frame[cc] = (unsigned char *)malloc(size))) Error("substitute_frame[] malloc failed\n"); if (base.scalable_mode==SC_SPAT) { /* this assumes lower layer is 4:2:0 */ if (!(llframe0[cc] = (unsigned char *)malloc((lower_layer_prediction_horizontal_size*lower_layer_prediction_vertical_size)/(cc?4:1)))) Error("llframe0 malloc failed\n"); if (!(llframe1[cc] = (unsigned char *)malloc((lower_layer_prediction_horizontal_size*lower_layer_prediction_vertical_size)/(cc?4:1)))) Error("llframe1 malloc failed\n"); } } /* SCALABILITY: Spatial */ if (base.scalable_mode==SC_SPAT) { if (!(lltmp = (short *)malloc(lower_layer_prediction_horizontal_size*((lower_layer_prediction_vertical_size*vertical_subsampling_factor_n)/vertical_subsampling_factor_m)*sizeof(short)))) Error("lltmp malloc failed\n"); }#ifdef DISPLAY if (Output_Type==T_X11) { Initialize_Display_Process(""); Initialize_Dither_Matrix(); }#endif /* DISPLAY */}void Error(text)char *text;{ fprintf(stderr,text); exit(1);}/* Trace_Flag output */void Print_Bits(code,bits,len)int code,bits,len;{ int i; for (i=0; i<len; i++) printf("%d",(code>>(bits-1-i))&1);}/* option processing */static void Process_Options(argc,argv)int argc; /* argument count */char *argv[]; /* argument vector */{ int i, LastArg, NextArg; /* at least one argument should be present */ if (argc<2) { printf("\n%s, %s\n",Version,Author); printf("Usage: mpeg2decode {options}\n\Options: -b file main bitstream (base or spatial enhancement layer)\n\ -cn file conformance report (n: level)\n\ -e file enhancement layer bitstream (SNR or Data Partitioning)\n\ -f store/display interlaced video in frame format\n\ -g concatenated file format for substitution method (-x)\n\ -in file information & statistics report (n: level)\n\ -l file file name pattern for lower layer sequence\n\ (for spatial scalability)\n\ -on file output format (0:YUV 1:SIF 2:TGA 3:PPM 4:X11 5:X11HiQ)\n\ -q disable warnings to stderr\n\ -r use double precision reference IDCT\n\ -t enable low level tracing to stdout\n\ -u file print user_data to stdio or file\n\ -vn verbose output (n: level)\n\ -x file filename pattern of picture substitution sequence\n\n\File patterns: for sequential filenames, \"printf\" style, e.g. rec%%d\n\ or rec%%d%%c for fieldwise storage\n\Levels: 0:none 1:sequence 2:picture 3:slice 4:macroblock 5:block\n\n\Example: mpeg2decode -b bitstream.mpg -f -r -o0 rec%%d\n\ \n"); exit(0); } Output_Type = -1; i = 1; /* command-line options are proceeded by '-' */ while(i < argc) { /* check if this is the last argument */ LastArg = ((argc-i)==1); /* parse ahead to see if another flag immediately follows current argument (this is used to tell if a filename is missing) */ if(!LastArg) NextArg = (argv[i+1][0]=='-'); else NextArg = 0; /* second character, [1], after '-' is the switch */ if(argv[i][0]=='-') { switch(toupper(argv[i][1])) { /* third character. [2], is the value */ case 'B': Main_Bitstream_Flag = 1; if(NextArg || LastArg) { printf("ERROR: -b must be followed the main bitstream filename\n"); } else Main_Bitstream_Filename = argv[++i]; break; case 'C':#ifdef VERIFY Verify_Flag = atoi(&argv[i][2]); if((Verify_Flag < NO_LAYER) || (Verify_Flag > ALL_LAYERS)) { printf("ERROR: -c level (%d) out of range [%d,%d]\n", Verify_Flag, NO_LAYER, ALL_LAYERS); exit(ERROR); }#else /* VERIFY */ printf("This program not compiled for Verify_Flag option\n");#endif /* VERIFY */ break; case 'E': Two_Streams = 1; /* either Data Partitioning (DP) or SNR Scalability enhancment */ if(NextArg || LastArg) { printf("ERROR: -e must be followed by filename\n"); exit(ERROR); } else Enhancement_Layer_Bitstream_Filename = argv[++i]; break;
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