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Diffstat (limited to 'libmpeg2/header.c')
| -rw-r--r-- | libmpeg2/header.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/libmpeg2/header.c b/libmpeg2/header.c new file mode 100644 index 0000000000..8f5b34359e --- /dev/null +++ b/libmpeg2/header.c @@ -0,0 +1,273 @@ +/* + * slice.c + * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca> + * + * This file is part of mpeg2dec, a free MPEG-2 video stream decoder. + * + * mpeg2dec is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * mpeg2dec is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include "config.h" + +#include <inttypes.h> + +#include "mpeg2_internal.h" +#include "attributes.h" + +// default intra quant matrix, in zig-zag order +static uint8_t default_intra_quantizer_matrix[64] ATTR_ALIGN(16) = { + 8, + 16, 16, + 19, 16, 19, + 22, 22, 22, 22, + 22, 22, 26, 24, 26, + 27, 27, 27, 26, 26, 26, + 26, 27, 27, 27, 29, 29, 29, + 34, 34, 34, 29, 29, 29, 27, 27, + 29, 29, 32, 32, 34, 34, 37, + 38, 37, 35, 35, 34, 35, + 38, 38, 40, 40, 40, + 48, 48, 46, 46, + 56, 56, 58, + 69, 69, + 83 +}; + +uint8_t scan_norm[64] ATTR_ALIGN(16) = +{ + // Zig-Zag scan pattern + 0, 1, 8,16, 9, 2, 3,10, + 17,24,32,25,18,11, 4, 5, + 12,19,26,33,40,48,41,34, + 27,20,13, 6, 7,14,21,28, + 35,42,49,56,57,50,43,36, + 29,22,15,23,30,37,44,51, + 58,59,52,45,38,31,39,46, + 53,60,61,54,47,55,62,63 +}; + +uint8_t scan_alt[64] ATTR_ALIGN(16) = +{ + // Alternate scan pattern + 0,8,16,24,1,9,2,10,17,25,32,40,48,56,57,49, + 41,33,26,18,3,11,4,12,19,27,34,42,50,58,35,43, + 51,59,20,28,5,13,6,14,21,29,36,44,52,60,37,45, + 53,61,22,30,7,15,23,31,38,46,54,62,39,47,55,63 +}; + +void header_state_init (picture_t * picture) +{ + //FIXME we should set pointers to the real scan matrices here (mmx vs + //normal) instead of the ifdefs in header_process_picture_coding_extension + + picture->scan = scan_norm; +} + +static const int frameratecode2framerate[16] = { + 0, 24000*10000/1001, 24*10000,25*10000, 30000*10000/1001, 30*10000,50*10000,60000*10000/1001, + 60*10000, 0,0,0,0,0,0,0 +}; + +int header_process_sequence_header (picture_t * picture, uint8_t * buffer) +{ + unsigned int h_size; + unsigned int v_size; + int i; + + if ((buffer[6] & 0x20) != 0x20) + return 1; // missing marker_bit + + v_size = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2]; + + picture->display_picture_width = (v_size >> 12); + picture->display_picture_height = (v_size & 0xfff); + + h_size = ((v_size >> 12) + 15) & ~15; + v_size = ((v_size & 0xfff) + 15) & ~15; + + if ((h_size > 768) || (v_size > 576)) + return 1; // size restrictions for MP@ML or MPEG1 + + //XXX this needs field fixups + picture->coded_picture_width = h_size; + picture->coded_picture_height = v_size; + picture->last_mba = ((h_size * v_size) >> 8) - 1; + + // this is not used by the decoder + picture->aspect_ratio_information = buffer[3] >> 4; + picture->frame_rate_code = buffer[3] & 15; + picture->frame_rate = frameratecode2framerate[picture->frame_rate_code]; + + picture->bitrate = (buffer[4]<<10)|(buffer[5]<<2)|(buffer[6]>>6); + + if (buffer[7] & 2) { + for (i = 0; i < 64; i++) + picture->intra_quantizer_matrix[scan_norm[i]] = + (buffer[i+7] << 7) | (buffer[i+8] >> 1); + buffer += 64; + } else { + for (i = 0; i < 64; i++) + picture->intra_quantizer_matrix[scan_norm[i]] = + default_intra_quantizer_matrix [i]; + } + + if (buffer[7] & 1) { + for (i = 0; i < 64; i++) + picture->non_intra_quantizer_matrix[scan_norm[i]] = + buffer[i+8]; + } else { + for (i = 0; i < 64; i++) + picture->non_intra_quantizer_matrix[i] = 16; + } + + // MPEG1 - for testing only + picture->mpeg1 = 1; + picture->intra_dc_precision = 0; + picture->frame_pred_frame_dct = 1; + picture->q_scale_type = 0; + picture->concealment_motion_vectors = 0; + //picture->alternate_scan = 0; + picture->picture_structure = FRAME_PICTURE; + //picture->second_field = 0; + + return 0; +} + +static int header_process_sequence_extension (picture_t * picture, + uint8_t * buffer) +{ + // MPEG1 - for testing only + picture->mpeg1 = 0; + + // check chroma format, size extensions, marker bit + if(((buffer[1]>>1)&3)!=1){ + printf("This CHROMA format not yet supported :(\n"); + return 1; + } + if ((buffer[1] & 1) || (buffer[2] & 0xe0)){ + printf("Big resolution video not yet supported :(\n"); + return 1; + } + if((buffer[3] & 0x01) != 0x01) return 1; // marker bit + + + // this is not used by the decoder + picture->progressive_sequence = (buffer[1] >> 3) & 1; + + if (picture->progressive_sequence) + picture->coded_picture_height = + (picture->coded_picture_height + 31) & ~31; + picture->bitrate>>=1; // hack + + return 0; +} + +static int header_process_quant_matrix_extension (picture_t * picture, + uint8_t * buffer) +{ + int i; + + if (buffer[0] & 8) { + for (i = 0; i < 64; i++) + picture->intra_quantizer_matrix[scan_norm[i]] = + (buffer[i] << 5) | (buffer[i+1] >> 3); + buffer += 64; + } + + if (buffer[0] & 4) { + for (i = 0; i < 64; i++) + picture->non_intra_quantizer_matrix[scan_norm[i]] = + (buffer[i] << 6) | (buffer[i+1] >> 2); + } + + return 0; +} + +static int header_process_picture_coding_extension (picture_t * picture, uint8_t * buffer) +{ + //pre subtract 1 for use later in compute_motion_vector + picture->f_code[0][0] = (buffer[0] & 15) - 1; + picture->f_code[0][1] = (buffer[1] >> 4) - 1; + picture->f_code[1][0] = (buffer[1] & 15) - 1; + picture->f_code[1][1] = (buffer[2] >> 4) - 1; + + picture->intra_dc_precision = (buffer[2] >> 2) & 3; + picture->picture_structure = buffer[2] & 3; + picture->frame_pred_frame_dct = (buffer[3] >> 6) & 1; + picture->concealment_motion_vectors = (buffer[3] >> 5) & 1; + picture->q_scale_type = (buffer[3] >> 4) & 1; + picture->intra_vlc_format = (buffer[3] >> 3) & 1; + + if (buffer[3] & 4) // alternate_scan + picture->scan = scan_alt; + else + picture->scan = scan_norm; + + // these are not used by the decoder + picture->top_field_first = buffer[3] >> 7; + picture->repeat_first_field = (buffer[3] >> 1) & 1; + picture->progressive_frame = buffer[4] >> 7; + + // repeat_first implementation by A'rpi/ESP-team, based on libmpeg3: + if(picture->repeat_count>=100) picture->repeat_count=0; + if(picture->repeat_first_field){ + if(picture->progressive_sequence){ + if(picture->top_field_first) + picture->repeat_count+=200; + else + picture->repeat_count+=100; + } else + if(picture->progressive_frame){ + picture->repeat_count+=50; + } + } + + return 0; +} + +int header_process_extension (picture_t * picture, uint8_t * buffer) +{ + switch (buffer[0] & 0xf0) { + case 0x10: // sequence extension + return header_process_sequence_extension (picture, buffer); + + case 0x30: // quant matrix extension + return header_process_quant_matrix_extension (picture, buffer); + + case 0x80: // picture coding extension + return header_process_picture_coding_extension (picture, buffer); + } + + return 0; +} + +int header_process_picture_header (picture_t *picture, uint8_t * buffer) +{ + picture->picture_coding_type = (buffer [1] >> 3) & 7; + + // forward_f_code and backward_f_code - used in mpeg1 only + picture->f_code[0][1] = (buffer[3] >> 2) & 1; + picture->f_code[0][0] = + (((buffer[3] << 1) | (buffer[4] >> 7)) & 7) - 1; + picture->f_code[1][1] = (buffer[4] >> 6) & 1; + picture->f_code[1][0] = ((buffer[4] >> 3) & 7) - 1; + + // move in header_process_picture_header + picture->second_field = + (picture->picture_structure != FRAME_PICTURE) && + !(picture->second_field); + + return 0; +} |