mirror of https://github.com/mpv-player/mpv
109 lines
3.3 KiB
C
109 lines
3.3 KiB
C
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// based on libmpeg2/header.c by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
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// #include <inttypes.h>
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#include <stdio.h>
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#include "config.h"
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#include "mpeg_hdr.h"
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static int frameratecode2framerate[16] = {
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0,
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// Official mpeg1/2 framerates: (1-8)
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24000*10000/1001, 24*10000,25*10000,
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30000*10000/1001, 30*10000,50*10000,
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60000*10000/1001, 60*10000,
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// Xing's 15fps: (9)
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15*10000,
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// libmpeg3's "Unofficial economy rates": (10-13)
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5*10000,10*10000,12*10000,15*10000,
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// some invalid ones: (14-15)
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0,0
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};
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int mp_header_process_sequence_header (mp_mpeg_header_t * picture, unsigned char * buffer)
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{
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int width, height;
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if ((buffer[6] & 0x20) != 0x20){
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printf("missing marker bit!\n");
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return 1; /* missing marker_bit */
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}
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height = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2];
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picture->display_picture_width = (height >> 12);
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picture->display_picture_height = (height & 0xfff);
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width = ((height >> 12) + 15) & ~15;
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height = ((height & 0xfff) + 15) & ~15;
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if ((width > 768) || (height > 576)){
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printf("size restrictions for MP@ML or MPEG1 exceeded! (%dx%d)\n",width,height);
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// return 1; /* size restrictions for MP@ML or MPEG1 */
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}
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picture->aspect_ratio_information = buffer[3] >> 4;
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picture->frame_rate_code = buffer[3] & 15;
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picture->fps=frameratecode2framerate[picture->frame_rate_code];
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picture->bitrate = (buffer[4]<<10)|(buffer[5]<<2)|(buffer[6]>>6);
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picture->mpeg1 = 1;
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picture->picture_structure = 3; //FRAME_PICTURE;
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picture->display_time=100;
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return 0;
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}
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static int header_process_sequence_extension (mp_mpeg_header_t * picture,
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unsigned char * buffer)
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{
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/* check chroma format, size extensions, marker bit */
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if ( ((buffer[1] & 0x06) == 0x00) ||
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((buffer[1] & 0x01) != 0x00) || (buffer[2] & 0xe0) ||
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((buffer[3] & 0x01) != 0x01) )
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return 1;
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picture->progressive_sequence = (buffer[1] >> 3) & 1;
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picture->mpeg1 = 0;
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return 0;
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}
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static int header_process_picture_coding_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
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{
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picture->picture_structure = buffer[2] & 3;
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picture->top_field_first = buffer[3] >> 7;
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picture->repeat_first_field = (buffer[3] >> 1) & 1;
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picture->progressive_frame = buffer[4] >> 7;
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// repeat_first implementation by A'rpi/ESP-team, based on libmpeg3:
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picture->display_time=100;
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if(picture->repeat_first_field){
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if(picture->progressive_sequence){
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if(picture->top_field_first)
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picture->display_time+=200;
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else
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picture->display_time+=100;
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} else
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if(picture->progressive_frame){
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picture->display_time+=50;
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}
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}
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//temopral hack. We calc time on every field, so if we have 2 fields
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// interlaced we'll end with double time for 1 frame
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if( picture->picture_structure!=3 ) picture->display_time/=2;
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return 0;
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}
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int mp_header_process_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
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{
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switch (buffer[0] & 0xf0) {
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case 0x10: /* sequence extension */
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return header_process_sequence_extension (picture, buffer);
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case 0x80: /* picture coding extension */
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return header_process_picture_coding_extension (picture, buffer);
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}
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return 0;
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}
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