PIC_MASK_COMPOSITE_DISPLAY) | PIC_FLAG_COMPOSITE_DISPLAY;    picture->flags = flags;    mpeg2dec->ext_state = PIC_DISPLAY_EXT | COPYRIGHT_EXT | QUANT_MATRIX_EXT;    return 0;}static int picture_display_ext (mpeg2dec_t * mpeg2dec){    uint8_t * buffer = mpeg2dec->chunk_start;    mpeg2_picture_t * picture = &(mpeg2dec->new_picture);    int i, nb_pos;    nb_pos = picture->nb_fields;    if (mpeg2dec->sequence.flags & SEQ_FLAG_PROGRESSIVE_SEQUENCE)	nb_pos >>= 1;    for (i = 0; i < nb_pos; i++) {	int x, y;	x = ((buffer[4*i] << 24) | (buffer[4*i+1] << 16) |	     (buffer[4*i+2] << 8) | buffer[4*i+3]) >> (11-2*i);	y = ((buffer[4*i+2] << 24) | (buffer[4*i+3] << 16) |	     (buffer[4*i+4] << 8) | buffer[4*i+5]) >> (10-2*i);	if (! (x & y & 1))	    return 1;	picture->display_offset[i].x = mpeg2dec->display_offset_x = x >> 1;	picture->display_offset[i].y = mpeg2dec->display_offset_y = y >> 1;    }    for (; i < 3; i++) {	picture->display_offset[i].x = mpeg2dec->display_offset_x;	picture->display_offset[i].y = mpeg2dec->display_offset_y;    }    return 0;}void mpeg2_header_picture_finalize (mpeg2dec_t * mpeg2dec, uint32_t accels){    mpeg2_decoder_t * decoder = &(mpeg2dec->decoder);    int old_type_b = (decoder->coding_type == B_TYPE);    int low_delay = mpeg2dec->sequence.flags & SEQ_FLAG_LOW_DELAY;    finalize_matrix (mpeg2dec);    decoder->coding_type = mpeg2dec->new_picture.flags & PIC_MASK_CODING_TYPE;    if (mpeg2dec->state == STATE_PICTURE) {	mpeg2_picture_t * picture;	mpeg2_picture_t * other;	decoder->second_field = 0;	picture = other = mpeg2dec->pictures;	if (old_type_b ^ (mpeg2dec->picture < mpeg2dec->pictures + 2))	    picture += 2;	else	    other += 2;	mpeg2dec->picture = picture;	*picture = mpeg2dec->new_picture;	if (!old_type_b) {	    mpeg2dec->fbuf[2] = mpeg2dec->fbuf[1];	    mpeg2dec->fbuf[1] = mpeg2dec->fbuf[0];	}	mpeg2dec->fbuf[0] = NULL;	mpeg2_reset_info (&(mpeg2dec->info));	mpeg2dec->info.current_picture = picture;	mpeg2dec->info.display_picture = picture;	if (decoder->coding_type != B_TYPE) {	    if (!low_delay) {		if (mpeg2dec->first) {		    mpeg2dec->info.display_picture = NULL;		    mpeg2dec->first = 0;		} else {		    mpeg2dec->info.display_picture = other;		    if (other->nb_fields == 1)			mpeg2dec->info.display_picture_2nd = other + 1;		    mpeg2dec->info.display_fbuf = mpeg2dec->fbuf[1];		}	    }	    if (!low_delay + !mpeg2dec->convert)		mpeg2dec->info.discard_fbuf =		    mpeg2dec->fbuf[!low_delay + !mpeg2dec->convert];	}	if (mpeg2dec->convert) {	    mpeg2_convert_init_t convert_init;	    if (!mpeg2dec->convert_start) {		int y_size, uv_size;		mpeg2dec->decoder.convert_id =		    mpeg2_malloc (mpeg2dec->convert_id_size,				  MPEG2_ALLOC_CONVERT_ID);		mpeg2dec->convert (MPEG2_CONVERT_START,				   mpeg2dec->decoder.convert_id,				   &(mpeg2dec->sequence),				   mpeg2dec->convert_stride, accels,				   mpeg2dec->convert_arg, &convert_init);		mpeg2dec->convert_start = convert_init.start;		mpeg2dec->decoder.convert = convert_init.copy;		y_size = decoder->stride_frame * mpeg2dec->sequence.height;		uv_size = y_size >> (2 - mpeg2dec->decoder.chroma_format);		mpeg2dec->yuv_buf[0][0] =		    (uint8_t *) mpeg2_malloc (y_size, MPEG2_ALLOC_YUV);		mpeg2dec->yuv_buf[0][1] =		    (uint8_t *) mpeg2_malloc (uv_size, MPEG2_ALLOC_YUV);		mpeg2dec->yuv_buf[0][2] =		    (uint8_t *) mpeg2_malloc (uv_size, MPEG2_ALLOC_YUV);		mpeg2dec->yuv_buf[1][0] =		    (uint8_t *) mpeg2_malloc (y_size, MPEG2_ALLOC_YUV);		mpeg2dec->yuv_buf[1][1] =		    (uint8_t *) mpeg2_malloc (uv_size, MPEG2_ALLOC_YUV);		mpeg2dec->yuv_buf[1][2] =		    (uint8_t *) mpeg2_malloc (uv_size, MPEG2_ALLOC_YUV);		y_size = decoder->stride_frame * 32;		uv_size = y_size >> (2 - mpeg2dec->decoder.chroma_format);		mpeg2dec->yuv_buf[2][0] =		    (uint8_t *) mpeg2_malloc (y_size, MPEG2_ALLOC_YUV);		mpeg2dec->yuv_buf[2][1] =		    (uint8_t *) mpeg2_malloc (uv_size, MPEG2_ALLOC_YUV);		mpeg2dec->yuv_buf[2][2] =		    (uint8_t *) mpeg2_malloc (uv_size, MPEG2_ALLOC_YUV);	    }	    if (!mpeg2dec->custom_fbuf) {		while (mpeg2dec->alloc_index < 3) {		    mpeg2_fbuf_t * fbuf;		    fbuf = &mpeg2dec->fbuf_alloc[mpeg2dec->alloc_index++].fbuf;		    fbuf->id = NULL;		    fbuf->buf[0] =			(uint8_t *) mpeg2_malloc (convert_init.buf_size[0],						  MPEG2_ALLOC_CONVERTED);		    fbuf->buf[1] =			(uint8_t *) mpeg2_malloc (convert_init.buf_size[1],						  MPEG2_ALLOC_CONVERTED);		    fbuf->buf[2] =			(uint8_t *) mpeg2_malloc (convert_init.buf_size[2],						  MPEG2_ALLOC_CONVERTED);		}		mpeg2_set_fbuf (mpeg2dec, (decoder->coding_type == B_TYPE));	    }	} else if (!mpeg2dec->custom_fbuf) {	    while (mpeg2dec->alloc_index < 3) {		mpeg2_fbuf_t * fbuf;		int y_size, uv_size;		fbuf = &(mpeg2dec->fbuf_alloc[mpeg2dec->alloc_index++].fbuf);		fbuf->id = NULL;		y_size = decoder->stride_frame * mpeg2dec->sequence.height;		uv_size = y_size >> (2 - decoder->chroma_format);		fbuf->buf[0] = (uint8_t *) mpeg2_malloc (y_size,							 MPEG2_ALLOC_YUV);		fbuf->buf[1] = (uint8_t *) mpeg2_malloc (uv_size,							 MPEG2_ALLOC_YUV);		fbuf->buf[2] = (uint8_t *) mpeg2_malloc (uv_size,							 MPEG2_ALLOC_YUV);	    }	    mpeg2_set_fbuf (mpeg2dec, (decoder->coding_type == B_TYPE));	}    } else {	decoder->second_field = 1;	mpeg2dec->picture++;	/* second field picture */	*(mpeg2dec->picture) = mpeg2dec->new_picture;	mpeg2dec->info.current_picture_2nd = mpeg2dec->picture;	if (low_delay || decoder->coding_type == B_TYPE)	    mpeg2dec->info.display_picture_2nd = mpeg2dec->picture;    }    info_user_data (mpeg2dec);}static int copyright_ext (mpeg2dec_t * mpeg2dec){    return 0;}static int quant_matrix_ext (mpeg2dec_t * mpeg2dec){    uint8_t * buffer = mpeg2dec->chunk_start;    int i, j;    for (i = 0; i < 4; i++)	if (buffer[0] & (8 >> i)) {	    for (j = 0; j < 64; j++)		mpeg2dec->new_quantizer_matrix[i][mpeg2_scan_norm[j]] =		    (buffer[j] << (i+5)) | (buffer[j+1] >> (3-i));	    mpeg2dec->copy_matrix |= 1 << i;	buffer += 64;    }    return 0;}int mpeg2_header_extension (mpeg2dec_t * mpeg2dec){    static int (* parser[]) (mpeg2dec_t *) = {	0, sequence_ext, sequence_display_ext, quant_matrix_ext,	copyright_ext, 0, 0, picture_display_ext, picture_coding_ext    };    int ext, ext_bit;    ext = mpeg2dec->chunk_start[0] >> 4;    ext_bit = 1 << ext;    if (!(mpeg2dec->ext_state & ext_bit))	return 0;	/* ignore illegal extensions */    mpeg2dec->ext_state &= ~ext_bit;    return parser[ext] (mpeg2dec);}int mpeg2_header_user_data (mpeg2dec_t * mpeg2dec){    mpeg2dec->user_data_len += mpeg2dec->chunk_ptr - 1 - mpeg2dec->chunk_start;    mpeg2dec->chunk_start = mpeg2dec->chunk_ptr - 1;        return 0;}static void prescale (mpeg2dec_t * mpeg2dec, int index){    static int non_linear_scale [] = {	 0,  1,  2,  3,  4,  5,   6,   7,	 8, 10, 12, 14, 16, 18,  20,  22,	24, 28, 32, 36, 40, 44,  48,  52,	56, 64, 72, 80, 88, 96, 104, 112    };    int i, j, k;    mpeg2_decoder_t * decoder = &(mpeg2dec->decoder);    if (mpeg2dec->scaled[index] != mpeg2dec->q_scale_type) {	mpeg2dec->scaled[index] = mpeg2dec->q_scale_type;	for (i = 0; i < 32; i++) {	    k = mpeg2dec->q_scale_type ? non_linear_scale[i] : (i << 1);	    for (j = 0; j < 64; j++)		decoder->quantizer_prescale[index][i][j] =		    k * mpeg2dec->quantizer_matrix[index][j];	}    }}mpeg2_state_t mpeg2_header_slice_start (mpeg2dec_t * mpeg2dec){    mpeg2_decoder_t * decoder = &(mpeg2dec->decoder);    mpeg2dec->info.user_data = NULL; mpeg2dec->info.user_data_len = 0;    mpeg2dec->state = ((mpeg2dec->picture->nb_fields > 1 ||			mpeg2dec->state == STATE_PICTURE_2ND) ?		       STATE_SLICE : STATE_SLICE_1ST);    if (mpeg2dec->decoder.coding_type != D_TYPE) {	prescale (mpeg2dec, 0);	if (decoder->chroma_quantizer[0] == decoder->quantizer_prescale[2])	    prescale (mpeg2dec, 2);	if (mpeg2dec->decoder.coding_type != I_TYPE) {	    prescale (mpeg2dec, 1);	    if (decoder->chroma_quantizer[1] == decoder->quantizer_prescale[3])		prescale (mpeg2dec, 3);	}    }    if (!(mpeg2dec->nb_decode_slices))	mpeg2dec->picture->flags |= PIC_FLAG_SKIP;    else if (mpeg2dec->convert_start) {	mpeg2dec->convert_start (decoder->convert_id, mpeg2dec->fbuf[0],				 mpeg2dec->picture, mpeg2dec->info.gop);	if (mpeg2dec->decoder.coding_type == B_TYPE)	    mpeg2_init_fbuf (&(mpeg2dec->decoder), mpeg2dec->yuv_buf[2],			     mpeg2dec->yuv_buf[mpeg2dec->yuv_index ^ 1],			     mpeg2dec->yuv_buf[mpeg2dec->yuv_index]);	else {	    mpeg2_init_fbuf (&(mpeg2dec->decoder),			     mpeg2dec->yuv_buf[mpeg2dec->yuv_index ^ 1],			     mpeg2dec->yuv_buf[mpeg2dec->yuv_index],			     mpeg2dec->yuv_buf[mpeg2dec->yuv_index]);	    if (mpeg2dec->state == STATE_SLICE)		mpeg2dec->yuv_index ^= 1;	}    } else {	int b_type;	b_type = (mpeg2dec->decoder.coding_type == B_TYPE);	mpeg2_init_fbuf (&(mpeg2dec->decoder), mpeg2dec->fbuf[0]->buf,			 mpeg2dec->fbuf[b_type + 1]->buf,			 mpeg2dec->fbuf[b_type]->buf);    }    mpeg2dec->action = NULL;    return STATE_INTERNAL_NORETURN;}static mpeg2_state_t seek_sequence (mpeg2dec_t * mpeg2dec){    mpeg2_reset_info (&(mpeg2dec->info));    mpeg2dec->info.sequence = NULL;    mpeg2dec->info.gop = NULL;    mpeg2_header_state_init (mpeg2dec);    mpeg2dec->action = mpeg2_seek_header;    return mpeg2_seek_header (mpeg2dec);}mpeg2_state_t mpeg2_header_end (mpeg2dec_t * mpeg2dec){    mpeg2_picture_t * picture;    int b_type;    b_type = (mpeg2dec->decoder.coding_type == B_TYPE);    picture = mpeg2dec->pictures;    if ((mpeg2dec->picture >= picture + 2) ^ b_type)	picture = mpeg2dec->pictures + 2;    mpeg2_reset_info (&(mpeg2dec->info));    if (!(mpeg2dec->sequence.flags & SEQ_FLAG_LOW_DELAY)) {	mpeg2dec->info.display_picture = picture;	if (picture->nb_fields == 1)	    mpeg2dec->info.display_picture_2nd = picture + 1;	mpeg2dec->info.display_fbuf = mpeg2dec->fbuf[b_type];	if (!mpeg2dec->convert)	    mpeg2dec->info.discard_fbuf = mpeg2dec->fbuf[b_type + 1];    } else if (!mpeg2dec->convert)	mpeg2dec->info.discard_fbuf = mpeg2dec->fbuf[b_type];    mpeg2dec->action = seek_sequence;    return STATE_END;}