bitstream.c

基于Linux的ffmepg decoder

#include "../../fmpeg4_driver/fmpeg4.h"
#include "bitstream.h"
#include "zigzag.h"
#include "../quant/quant_matrix.h"
#include "../local_mem.h"
#include "../define.h"
#include "../vpe_m.h"

//int old_time_incre;
uint32_t time_increment_resolution;
/*****************************************************************************
 * Functions
 ****************************************************************************/
static int32_t vop_width[8] = {0, 128, 176, 352, 704, 1408, 0, 0};
static int32_t vop_height[8] = {0, 96, 144, 288, 576, 1152, 0, 0};


static uint32_t __inline
log2bin(uint32_t value)
{
/* Changed by Chenm001 */
	int n = 0;

	while (value) {
		value >>= 1;
		n++;
	}
	return n;
}

/*
static const uint32_t intra_dc_threshold_table[] = {
	32,							// never use
	13,
	15,
	17,
	19,
	21,
	23,
	1,
};
*/

void
bs_get_matrix(Bitstream * bs,
			  uint8_t * matrix)
{
	int i = 0, j = 0;
	int last, value = 0;
	do {
		last = value;
		j++;
		if (j == 8) {
			j=0;
		}
		value = BitstreamGetBits(bs, 8);
		matrix[scan_tables[0][i++]] = value;
	}
	while (value != 0 && i < 64);
    i--;    /* fix little bug at coeff not full */

	while (i < 64) {
		matrix[scan_tables[0][i++]] = last;
	}
}



bool
bRead_video_packet_header(DECODER * dec,
						int *fcode_forward,
						int *fcode_backward,
						int32_t * mbnum)
{
	int tmp;
	int coding_type;
	uint32_t * table = (uint32_t *)((uint32_t) dec->pu32BaseAddr + TABLE_OUTPUT_OFF);

	tmp = table[0];
	// macroblock_number
	if (dec->h263==1)
		*mbnum = ((tmp  & 0xFFFF) >> 2) * dec->mb_width;
	else {
		*mbnum = tmp  & 0xFFFF;
		//extent bit
		if (tmp & BIT24) {
			tmp = table[2];
			coding_type = tmp & 0xff;
			// hardware not support
			if (coding_type >= B_VOP)
				return -1;
			if (coding_type != I_VOP && *fcode_forward)
				*fcode_forward = (tmp >> 16) & 0xff;
			if (coding_type == B_VOP && *fcode_backward)
				*fcode_backward = 0;
		}
	}
	return 0;
}


/*
decode headers
returns coding_type, or -1 if error
*/

#define VIDOBJ_START_CODE_MASK		0x0000001f
#define VIDOBJLAY_START_CODE_MASK	0x0000000f
#define VIDO_SHORT_HEADER_MASK 0x000003ff
#define VIDO_SHORT_HEADER 0x8000
#define VIDO_SHORT_HEADER_END 0x3f

int
BitstreamReadHeaders(Bitstream * bs,
					 DECODER * dec,
					 uint32_t * rounding,
					 uint32_t * quant,
					 uint32_t * fcode_forward,
					 uint32_t * fcode_backward,
					 uint32_t * intra_dc_threshold_bit)
{
	uint32_t vol_ver_id;
	uint32_t coding_type;
	uint32_t start_code;
	uint32_t time_incr = 0;
	int32_t time_increment = 0;
	do {
		BitstreamByteAlign(bs);
		start_code = BitstreamShowBits(bs, 32);
#ifndef FPGA
		mVpe_Indicator(0x93000000 | (start_code >> 16));
		mVpe_Indicator(0x93000000 | (start_code & 0xFFFF));
#endif
		if (start_code == VISOBJSEQ_START_CODE) {

			int profile;
			BitstreamSkip(bs, 32);	/* visual_object_sequence_start_code */
			profile = BitstreamGetBits(bs, 8);	/* profile_and_level_indication */
		} else if (start_code == VISOBJSEQ_STOP_CODE) {
			BitstreamSkip(bs, 32);	/* visual_object_sequence_stop_code */
		} else if (start_code == VISOBJ_START_CODE) {
			BitstreamSkip(bs, 32);	/* visual_object_start_code */
			if (BitstreamGetBit(bs))	/* is_visual_object_identified */
			{
				vol_ver_id = BitstreamGetBits(bs, 4);	/* visual_object_ver_id */
				BitstreamSkip(bs, 3);	/* visual_object_priority */
			} else {
				vol_ver_id = 1;
			}

			if (BitstreamShowBits(bs, 4) != VISOBJ_TYPE_VIDEO)	/* visual_object_type */
			{
				return -1;
			}
			BitstreamSkip(bs, 4);

			/* video_signal_type */

			if (BitstreamGetBit(bs))	/* video_signal_type */
			{
				BitstreamSkip(bs, 3);	/* video_format */
				BitstreamSkip(bs, 1);	/* video_range */
				if (BitstreamGetBit(bs))	/* color_description */
				{
					BitstreamSkip(bs, 8);	/* color_primaries */
					BitstreamSkip(bs, 8);	/* transfer_characteristics */
					BitstreamSkip(bs, 8);	/* matrix_coefficients */
				}
			}
		} else if ((start_code & ~VIDOBJ_START_CODE_MASK) == VIDOBJ_START_CODE) {
			BitstreamSkip(bs, 32);	/* video_object_start_code */
		} else if ((start_code & ~VIDO_SHORT_HEADER_MASK) == VIDO_SHORT_HEADER) {
			int temp, pei, psupp = 0;
			uint32_t width, height;		// ben add

			dec->h263 = 1;
			dec->quant_type = 0;
			*fcode_forward = 1;
			dec->quarterpel = 0;
			BitstreamSkip(bs, 22);
			BitstreamSkip(bs, 8);
			READ_MARKER();
			temp = BitstreamGetBit(bs);			//  zero_bit
			dec->split_screen_indicator = BitstreamGetBit(bs);			//  split_screen_indicator
			dec->document_camera_indicator = BitstreamGetBit(bs);			//  document_camera_indicator
			dec->full_picture_freeze_release = BitstreamGetBit(bs);			//  full_picture_freeze_release
			dec->source_format = BitstreamGetBits(bs,3);			//  source_format
			dec->picture_coding_type = BitstreamGetBit(bs);			//  picture_coding_type
			temp = BitstreamGetBits(bs,4);			//  four_reserved_zero_bits
			*quant = BitstreamGetBits(bs,5);		//	quant
			temp = BitstreamGetBit(bs);			//  zero_bit
			do {
				pei = BitstreamGetBit(bs);
				if (pei == 1)
					psupp=BitstreamGetBits(bs,8);
			} while (pei == 1);

			width = vop_width[dec->source_format];
			height = vop_height[dec->source_format];
//ben add
#if 0
			dec->width = width;
			dec->height = height;
#else
			/* for auto set width & height */
			if (dec->width == 0)	
				dec->width = width;
			if (dec->height == 0)
				dec->height = height;
			if (width != dec->width || height != dec->height)
				return -1;
#endif
			return dec->picture_coding_type;
		}
		else if ((start_code & ~VIDOBJLAY_START_CODE_MASK) == VIDOBJLAY_START_CODE) {
			BitstreamSkip(bs, 32);	/* video_object_layer_start_code */
			BitstreamSkip(bs, 1);	/* random_accessible_vol */

			dec->h263 = 0;
			/* video_object_type_indication */
			if (BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_SIMPLE && BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_CORE && BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_MAIN && BitstreamShowBits(bs, 8) != 0)	/* BUGGY DIVX */
			{
				return -1;
			}
			BitstreamSkip(bs, 8);


			if (BitstreamGetBit(bs))	/* is_object_layer_identifier */
			{
				vol_ver_id = BitstreamGetBits(bs, 4);	/* video_object_layer_verid */
				BitstreamSkip(bs, 3);	/* video_object_layer_priority */
			} else {
				vol_ver_id = 1;
			}

			if (BitstreamGetBits(bs, 4) == VIDOBJLAY_AR_EXTPAR)	/* aspect_ratio_info */
			{
				BitstreamSkip(bs, 8);	/* par_width */
				BitstreamSkip(bs, 8);	/* par_height */
			}

			if (BitstreamGetBit(bs))	/* vol_control_parameters */
			{
				BitstreamSkip(bs, 2);	/* chroma_format */
				dec->low_delay = (uint8_t)BitstreamGetBit(bs);	/* low_delay */
				if (BitstreamGetBit(bs))	/* vbv_parameters */
				{
					BitstreamSkip(bs, 15);	/* first_half_bitrate */
					READ_MARKER();
					BitstreamSkip(bs, 15);	/* latter_half_bitrate */
					READ_MARKER();
					BitstreamSkip(bs, 15);	/* first_half_vbv_buffer_size */
					READ_MARKER();
					BitstreamSkip(bs, 3);	/* latter_half_vbv_buffer_size */
					BitstreamSkip(bs, 11);	/* first_half_vbv_occupancy */
					READ_MARKER();
					BitstreamSkip(bs, 15);	/* latter_half_vbv_occupancy */
					READ_MARKER();

				}
			}

			dec->shape = BitstreamGetBits(bs, 2);	/* video_object_layer_shape */

			if (dec->shape == VIDOBJLAY_SHAPE_GRAYSCALE && vol_ver_id != 1) {
				BitstreamSkip(bs, 4);	/* video_object_layer_shape_extension */
			}

			READ_MARKER();

/* *************************** for decode B-frame time *********************** */
			time_increment_resolution = BitstreamGetBits(bs, 16);	/* vop_time_increment_resolution */

/*			time_increment_resolution--; */

			if (time_increment_resolution > 0) {
				dec->time_inc_bits = MAX(log2bin(time_increment_resolution-1), 1);
			} else {
				/* dec->time_inc_bits = 0; */
				/* for "old" xvid compatibility, set time_inc_bits = 1 */
				dec->time_inc_bits = 1;
			}