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/*
* header.c
* Copyright (C) 2000-2002 Michel Lespinasse <walken@zoy.org>
* Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
*
* This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
* See http://libmpeg2.sourceforge.net/ for updates.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/*
#define LOG_PAN_SCAN
*/
#include "config.h"
#include <stdio.h> /* For printf debugging */
#include <inttypes.h>
#include "mpeg2_internal.h"
#include <xine/attributes.h>
/* default intra quant matrix, in zig-zag order */
static const 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 mpeg2_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 mpeg2_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
};
/* count must be between 1 and 32 */
static uint32_t get_bits(uint8_t *buffer, uint32_t count, uint32_t *bit_position) {
uint32_t byte_offset;
uint32_t bit_offset;
uint32_t bit_mask;
uint32_t bit_bite;
uint32_t result=0;
if (count == 0) return 0;
do {
byte_offset = *bit_position >> 3; /* Div 8 */
bit_offset = 8 - (*bit_position & 0x7); /* Bits got 87654321 */
bit_mask = ((1 << (bit_offset)) - 1);
bit_bite = bit_offset;
if (count < bit_offset) {
bit_mask ^= ((1 << (bit_offset-count)) - 1);
bit_bite = count;
}
/*
printf("Byte=0x%02x Bitmask=0x%04x byte_offset=%u bit_offset=%u bit_byte=%u count=%u\n",buffer[byte_offset], bit_mask, byte_offset, bit_offset, bit_bite,count);
*/
result = (result << bit_bite) | ((buffer[byte_offset] & bit_mask) >> (bit_offset-bit_bite));
*bit_position+=bit_bite;
count-=bit_bite;
} while ((count > 0) && (byte_offset<50) );
return result;
}
static int32_t get_bits_signed(uint8_t *buffer, uint32_t count, uint32_t *bit_position) {
uint32_t value = get_bits(buffer, count, bit_position);
uint32_t sign_mask = (uint32_t)(-1 << (count - 1));
if (value & sign_mask)
value |= sign_mask; /* sign-extend value */
return (int32_t)value;
}
void mpeg2_header_state_init (picture_t * picture)
{
picture->scan = mpeg2_scan_norm;
picture->load_intra_quantizer_matrix = 1;
picture->load_non_intra_quantizer_matrix = 1;
}
int mpeg2_header_sequence (picture_t * picture, uint8_t * buffer)
{
int width, height;
int i;
if ((buffer[6] & 0x20) != 0x20)
return 1; /* missing marker_bit */
height = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2];
picture->display_width = width = (height >> 12);
picture->display_height = height = (height & 0xfff);
width = (width + 15) & ~15;
height = (height + 15) & ~15;
if ((width > 1920) || (height > 1152))
return 1; /* size restrictions for MP@HL */
picture->coded_picture_width = width;
picture->coded_picture_height = height;
/* this is not used by the decoder */
picture->aspect_ratio_information = buffer[3] >> 4;
picture->frame_rate_code = buffer[3] & 15;
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[mpeg2_scan_norm[i]] =
(buffer[i+7] << 7) | (buffer[i+8] >> 1);
buffer += 64;
} else
for (i = 0; i < 64; i++)
picture->intra_quantizer_matrix[mpeg2_scan_norm[i]] =
default_intra_quantizer_matrix [i];
if (buffer[7] & 1)
for (i = 0; i < 64; i++)
picture->non_intra_quantizer_matrix[mpeg2_scan_norm[i]] =
buffer[i+8];
else
for (i = 0; i < 64; i++)
picture->non_intra_quantizer_matrix[i] = 16;
picture->load_intra_quantizer_matrix = 1;
picture->load_non_intra_quantizer_matrix = 1;
/* 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 sequence_extension (picture_t * picture, uint8_t * buffer)
{
/* check chroma format, size extensions, marker bit */
if (((buffer[1] & 0x07) != 0x02) || (buffer[2] & 0xe0) ||
((buffer[3] & 0x01) != 0x01))
return 1;
/* this is not used by the decoder */
picture->progressive_sequence = (buffer[1] >> 3) & 1;
picture->low_delay = buffer[5] & 0x80;
if (!picture->progressive_sequence)
picture->coded_picture_height =
(picture->coded_picture_height + 31) & ~31;
/* printf ("libmpeg2: low_delay : %d\n", picture->low_delay); */
/*
printf ("libmpeg2: sequence extension+5 : %08x (%d)\n",
buffer[5], buffer[5] % 0x80);
*/
picture->frame_rate_ext_n = buffer[5] & 0x31;
picture->frame_rate_ext_d = (buffer[5] >> 2) & 0x03;
/* MPEG1 - for testing only */
picture->mpeg1 = 0;
return 0;
}
static int 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[mpeg2_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[mpeg2_scan_norm[i]] =
(buffer[i] << 6) | (buffer[i+1] >> 2);
return 0;
}
static int picture_coding_extension (picture_t * picture, uint8_t * buffer)
{
/* pre subtract 1 for use later in compute_motion_vector */
picture->f_motion.f_code[0] = (buffer[0] & 15) - 1;
picture->f_motion.f_code[1] = (buffer[1] >> 4) - 1;
picture->b_motion.f_code[0] = (buffer[1] & 15) - 1;
picture->b_motion.f_code[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 = mpeg2_scan_alt;
else
picture->scan = mpeg2_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;
return 0;
}
static int sequence_display_extension (picture_t * picture, uint8_t * buffer) {
/* FIXME: implement. */
uint32_t bit_position;
/*uint32_t padding;*/
bit_position = 0;
/*padding = get_bits(buffer, 4, &bit_position);*/ bit_position += 4;
picture->video_format = get_bits(buffer, 3, &bit_position);
picture->colour_description = get_bits(buffer, 1, &bit_position);
if(picture->colour_description) {
picture->colour_primatives = get_bits(buffer, 8, &bit_position);
picture->transfer_characteristics = get_bits(buffer, 8, &bit_position);
picture->matrix_coefficients = get_bits(buffer, 8, &bit_position);
}
picture->display_horizontal_size = get_bits(buffer, 14, &bit_position);
/*padding = get_bits(buffer, 1, &bit_position);*/ bit_position++;
picture->display_vertical_size = get_bits(buffer, 14, &bit_position);
#ifdef LOG_PAN_SCAN
printf("Sequence_display_extension\n");
printf(" video_format: %u\n", picture->video_format);
printf(" colour_description: %u\n", picture->colour_description);
if(picture->colour_description) {
printf(" colour_primatives: %u\n", picture->colour_primatives);
printf(" transfer_characteristics %u\n", picture->transfer_characteristics);
printf(" matrix_coefficients %u\n", picture->matrix_coefficients);
}
printf(" display_horizontal_size %u\n", picture->display_horizontal_size);
printf(" display_vertical_size %u\n", picture->display_vertical_size);
#endif
return 0;
}
static int picture_display_extension (picture_t * picture, uint8_t * buffer) {
uint32_t bit_position;
/*uint32_t padding;*/
#ifdef LOG_PAN_SCAN
printf ("libmpeg2: picture_display_extension\n");
#endif
bit_position = 0;
/*padding = get_bits(buffer, 4, &bit_position);*/ bit_position += 4;
picture->frame_centre_horizontal_offset = get_bits_signed(buffer, 16, &bit_position);
/*padding = get_bits(buffer, 1, &bit_position);*/ bit_position++;
picture->frame_centre_vertical_offset = get_bits_signed(buffer, 16, &bit_position);
/*padding = get_bits(buffer, 1, &bit_position);*/ bit_position++;
#ifdef LOG_PAN_SCAN
printf("Pan & Scan centre (x,y) = (%d, %d)\n",
picture->frame_centre_horizontal_offset,
picture->frame_centre_vertical_offset);
#endif
return 0;
}
int mpeg2_header_extension (picture_t * picture, uint8_t * buffer)
{
switch (buffer[0] & 0xf0) {
case 0x00: /* reserved */
return 0;
case 0x10: /* sequence extension */
return sequence_extension (picture, buffer);
case 0x20: /* sequence display extension for Pan & Scan */
return sequence_display_extension (picture, buffer);
case 0x30: /* quant matrix extension */
return quant_matrix_extension (picture, buffer);
case 0x40: /* copyright extension */
return 0;
case 0x50: /* sequence scalable extension */
return 0;
case 0x60: /* reserved */
return 0;
case 0x70: /* picture display extension for Pan & Scan */
return picture_display_extension (picture, buffer);
case 0x80: /* picture coding extension */
return picture_coding_extension (picture, buffer);
case 0x90: /* picture spacial scalable extension */
return 0;
case 0xA0: /* picture temporal scalable extension */
return 0;
case 0xB0: /* camera parameters extension */
return 0;
case 0xC0: /* ITU-T extension */
return 0;
case 0xD0: /* reserved */
return 0;
case 0xE0: /* reserved */
return 0;
case 0xF0: /* reserved */
return 0;
}
return 0;
}
int mpeg2_header_group_of_pictures (picture_t * picture, uint8_t * buffer) {
uint32_t bit_position;
/*uint32_t padding;*/
bit_position = 0;
picture->drop_frame_flag = get_bits(buffer, 1, &bit_position);
picture->time_code_hours = get_bits(buffer, 5, &bit_position);
picture->time_code_minutes = get_bits(buffer, 6, &bit_position);
/*padding = get_bits(buffer, 1, &bit_position);*/ bit_position++;
picture->time_code_seconds = get_bits(buffer, 6, &bit_position);
picture->time_code_pictures = get_bits(buffer, 6, &bit_position);
picture->closed_gop = get_bits(buffer, 1, &bit_position);
picture->broken_link = get_bits(buffer, 1, &bit_position);
#ifdef LOG_PAN_SCAN
printf("Group of pictures\n");
printf(" drop_frame_flag: %u\n", picture->drop_frame_flag);
printf(" time_code: HH:MM:SS:Pictures %02u:%02u:%02u:%02u\n",
picture->time_code_hours,
picture->time_code_minutes,
picture->time_code_seconds,
picture->time_code_pictures);
printf(" closed_gop: %u\n", picture->closed_gop);
printf(" bloken_link: %u\n", picture->broken_link);
#endif
return 0;
}
int mpeg2_header_picture (picture_t * picture, uint8_t * buffer)
{
picture->picture_coding_type = (buffer [1] >> 3) & 7;
picture->vbv_delay = ((buffer[1] << 13) | (buffer[2] << 5) |
(buffer[3] >> 3)) & 0xffff;
/* forward_f_code and backward_f_code - used in mpeg1 only */
picture->f_motion.f_code[1] = (buffer[3] >> 2) & 1;
picture->f_motion.f_code[0] =
(((buffer[3] << 1) | (buffer[4] >> 7)) & 7) - 1;
picture->b_motion.f_code[1] = (buffer[4] >> 6) & 1;
picture->b_motion.f_code[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;
}