puthdr.c
资源名称:mpeg2编解码.zip [点击查看]
上传用户:hkgotone
上传日期:2013-02-17
资源大小:293k
文件大小:7k
源码类别:
Windows Mobile
开发平台:
C/C++
- /* puthdr.c, generation of headers */
- /* 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 <math.h>
- #include "config.h"
- #include "global.h"
- /* private prototypes */
- static int frametotc _ANSI_ARGS_((int frame));
- /* generate sequence header (6.2.2.1, 6.3.3)
- *
- * matrix download not implemented
- */
- void putseqhdr()
- {
- int i;
- alignbits();
- putbits(SEQ_START_CODE,32); /* sequence_header_code */
- putbits(horizontal_size,12); /* horizontal_size_value */
- putbits(vertical_size,12); /* vertical_size_value */
- putbits(aspectratio,4); /* aspect_ratio_information */
- putbits(frame_rate_code,4); /* frame_rate_code */
- putbits((int)ceil(bit_rate/400.0),18); /* bit_rate_value */
- putbits(1,1); /* marker_bit */
- putbits(vbv_buffer_size,10); /* vbv_buffer_size_value */
- putbits(constrparms,1); /* constrained_parameters_flag */
- putbits(load_iquant,1); /* load_intra_quantizer_matrix */
- if (load_iquant)
- for (i=0; i<64; i++) /* matrices are always downloaded in zig-zag order */
- putbits(intra_q[zig_zag_scan[i]],8); /* intra_quantizer_matrix */
- putbits(load_niquant,1); /* load_non_intra_quantizer_matrix */
- if (load_niquant)
- for (i=0; i<64; i++)
- putbits(inter_q[zig_zag_scan[i]],8); /* non_intra_quantizer_matrix */
- }
- /* generate sequence extension (6.2.2.3, 6.3.5) header (MPEG-2 only) */
- void putseqext()
- {
- alignbits();
- putbits(EXT_START_CODE,32); /* extension_start_code */
- putbits(SEQ_ID,4); /* extension_start_code_identifier */
- putbits((profile<<4)|level,8); /* profile_and_level_indication */
- putbits(prog_seq,1); /* progressive sequence */
- putbits(chroma_format,2); /* chroma_format */
- putbits(horizontal_size>>12,2); /* horizontal_size_extension */
- putbits(vertical_size>>12,2); /* vertical_size_extension */
- putbits(((int)ceil(bit_rate/400.0))>>18,12); /* bit_rate_extension */
- putbits(1,1); /* marker_bit */
- putbits(vbv_buffer_size>>10,8); /* vbv_buffer_size_extension */
- putbits(0,1); /* low_delay -- currently not implemented */
- putbits(0,2); /* frame_rate_extension_n */
- putbits(0,5); /* frame_rate_extension_d */
- }
- /* generate sequence display extension (6.2.2.4, 6.3.6)
- *
- * content not yet user setable
- */
- void putseqdispext()
- {
- alignbits();
- putbits(EXT_START_CODE,32); /* extension_start_code */
- putbits(DISP_ID,4); /* extension_start_code_identifier */
- putbits(video_format,3); /* video_format */
- putbits(1,1); /* colour_description */
- putbits(color_primaries,8); /* colour_primaries */
- putbits(transfer_characteristics,8); /* transfer_characteristics */
- putbits(matrix_coefficients,8); /* matrix_coefficients */
- putbits(display_horizontal_size,14); /* display_horizontal_size */
- putbits(1,1); /* marker_bit */
- putbits(display_vertical_size,14); /* display_vertical_size */
- }
- /* output a zero terminated string as user data (6.2.2.2.2, 6.3.4.1)
- *
- * string must not emulate start codes
- */
- void putuserdata(userdata)
- char *userdata;
- {
- alignbits();
- putbits(USER_START_CODE,32); /* user_data_start_code */
- while (*userdata)
- putbits(*userdata++,8);
- }
- /* generate group of pictures header (6.2.2.6, 6.3.9)
- *
- * uses tc0 (timecode of first frame) and frame0 (number of first frame)
- */
- void putgophdr(frame,closed_gop)
- int frame,closed_gop;
- {
- int tc;
- alignbits();
- putbits(GOP_START_CODE,32); /* group_start_code */
- tc = frametotc(tc0+frame);
- putbits(tc,25); /* time_code */
- putbits(closed_gop,1); /* closed_gop */
- putbits(0,1); /* broken_link */
- }
- /* convert frame number to time_code
- *
- * drop_frame not implemented
- */
- static int frametotc(frame)
- int frame;
- {
- int fps, pict, sec, minute, hour, tc;
- fps = (int)(frame_rate+0.5);
- pict = frame%fps;
- frame = (frame-pict)/fps;
- sec = frame%60;
- frame = (frame-sec)/60;
- minute = frame%60;
- frame = (frame-minute)/60;
- hour = frame%24;
- tc = (hour<<19) | (minute<<13) | (1<<12) | (sec<<6) | pict;
- return tc;
- }
- /* generate picture header (6.2.3, 6.3.10) */
- void putpicthdr()
- {
- alignbits();
- putbits(PICTURE_START_CODE,32); /* picture_start_code */
- calc_vbv_delay();
- putbits(temp_ref,10); /* temporal_reference */
- putbits(pict_type,3); /* picture_coding_type */
- putbits(vbv_delay,16); /* vbv_delay */
- if (pict_type==P_TYPE || pict_type==B_TYPE)
- {
- putbits(0,1); /* full_pel_forward_vector */
- if (mpeg1)
- putbits(forw_hor_f_code,3);
- else
- putbits(7,3); /* forward_f_code */
- }
- if (pict_type==B_TYPE)
- {
- putbits(0,1); /* full_pel_backward_vector */
- if (mpeg1)
- putbits(back_hor_f_code,3);
- else
- putbits(7,3); /* backward_f_code */
- }
- putbits(0,1); /* extra_bit_picture */
- }
- /* generate picture coding extension (6.2.3.1, 6.3.11)
- *
- * composite display information (v_axis etc.) not implemented
- */
- void putpictcodext()
- {
- alignbits();
- putbits(EXT_START_CODE,32); /* extension_start_code */
- putbits(CODING_ID,4); /* extension_start_code_identifier */
- putbits(forw_hor_f_code,4); /* forward_horizontal_f_code */
- putbits(forw_vert_f_code,4); /* forward_vertical_f_code */
- putbits(back_hor_f_code,4); /* backward_horizontal_f_code */
- putbits(back_vert_f_code,4); /* backward_vertical_f_code */
- putbits(dc_prec,2); /* intra_dc_precision */
- putbits(pict_struct,2); /* picture_structure */
- putbits((pict_struct==FRAME_PICTURE)?topfirst:0,1); /* top_field_first */
- putbits(frame_pred_dct,1); /* frame_pred_frame_dct */
- putbits(0,1); /* concealment_motion_vectors -- currently not implemented */
- putbits(q_scale_type,1); /* q_scale_type */
- putbits(intravlc,1); /* intra_vlc_format */
- putbits(altscan,1); /* alternate_scan */
- putbits(repeatfirst,1); /* repeat_first_field */
- putbits(prog_frame,1); /* chroma_420_type */
- putbits(prog_frame,1); /* progressive_frame */
- putbits(0,1); /* composite_display_flag */
- }
- /* generate sequence_end_code (6.2.2) */
- void putseqend()
- {
- alignbits();
- putbits(SEQ_END_CODE,32);
- }