slice.c

mpeg2 decoder filter过滤服务端

	} else if (bit_buf >= 0x00800000) {
	    tab = DCT_13 + (UBITS (bit_buf, 13) - 16);
	    i += tab->run;
	    if (i < 64)
		goto normal_code;
	} else if (bit_buf >= 0x00200000) {
	    tab = DCT_15 + (UBITS (bit_buf, 15) - 16);
	    i += tab->run;
	    if (i < 64)
		goto normal_code;
	} else {
	    tab = DCT_16 + UBITS (bit_buf, 16);
	    bit_buf <<= 16;
	    GETWORD (bit_buf, bits + 16, bit_ptr);
	    i += tab->run;
	    if (i < 64)
		goto normal_code;
	}
	break;	/* illegal, check needed to avoid buffer overflow */
    }
    DUMPBITS (bit_buf, bits, 2);	/* dump end of block code */
    decoder->bitstream_buf = bit_buf;
    decoder->bitstream_bits = bits;
    decoder->bitstream_ptr = bit_ptr;
}

static int get_mpeg1_non_intra_block (mpeg2_decoder_t * const decoder)
{
    int i;
    int j;
    int val;
    const uint8_t * const scan = decoder->scan;
    const uint16_t * const quant_matrix = decoder->quantizer_matrix[1];
    const DCTtab * tab;
    uint32_t bit_buf;
    int bits;
    const uint8_t * bit_ptr;
    int16_t * const dest = decoder->DCTblock;

    i = -1;

    bit_buf = decoder->bitstream_buf;
    bits = decoder->bitstream_bits;
    bit_ptr = decoder->bitstream_ptr;

    NEEDBITS (bit_buf, bits, bit_ptr);
    if (bit_buf >= 0x28000000) {
	tab = DCT_B14DC_5 + (UBITS (bit_buf, 5) - 5);
	goto entry_1;
    } else
	goto entry_2;

    while (1) {
	if (bit_buf >= 0x28000000) {

	    tab = DCT_B14AC_5 + (UBITS (bit_buf, 5) - 5);

	entry_1:
	    i += tab->run;
	    if (i >= 64)
		break;	/* end of block */

	normal_code:
	    j = scan[i];
	    bit_buf <<= tab->len;
	    bits += tab->len + 1;
	    val = ((2 * tab->level + 1) * quant_matrix[j]) >> 5;

	    /* oddification */
	    val = (val - 1) | 1;

	    /* if (bitstream_get (1)) val = -val; */
	    val = (val ^ SBITS (bit_buf, 1)) - SBITS (bit_buf, 1);

	    SATURATE (val);
	    dest[j] = val;

	    bit_buf <<= 1;
	    NEEDBITS (bit_buf, bits, bit_ptr);

	    continue;

	}

    entry_2:
	if (bit_buf >= 0x04000000) {

	    tab = DCT_B14_8 + (UBITS (bit_buf, 8) - 4);

	    i += tab->run;
	    if (i < 64)
		goto normal_code;

	    /* escape code */

	    i += UBITS (bit_buf << 6, 6) - 64;
	    if (i >= 64)
		break;	/* illegal, check needed to avoid buffer overflow */

	    j = scan[i];

	    DUMPBITS (bit_buf, bits, 12);
	    NEEDBITS (bit_buf, bits, bit_ptr);
	    val = SBITS (bit_buf, 8);
	    if (! (val & 0x7f)) {
		DUMPBITS (bit_buf, bits, 8);
		val = UBITS (bit_buf, 8) + 2 * val;
	    }
	    val = 2 * (val + SBITS (val, 1)) + 1;
	    val = (val * quant_matrix[j]) / 32;

	    /* oddification */
	    val = (val + ~SBITS (val, 1)) | 1;

	    SATURATE (val);
	    dest[j] = val;

	    DUMPBITS (bit_buf, bits, 8);
	    NEEDBITS (bit_buf, bits, bit_ptr);

	    continue;

	} else if (bit_buf >= 0x02000000) {
	    tab = DCT_B14_10 + (UBITS (bit_buf, 10) - 8);
	    i += tab->run;
	    if (i < 64)
		goto normal_code;
	} else if (bit_buf >= 0x00800000) {
	    tab = DCT_13 + (UBITS (bit_buf, 13) - 16);
	    i += tab->run;
	    if (i < 64)
		goto normal_code;
	} else if (bit_buf >= 0x00200000) {
	    tab = DCT_15 + (UBITS (bit_buf, 15) - 16);
	    i += tab->run;
	    if (i < 64)
		goto normal_code;
	} else {
	    tab = DCT_16 + UBITS (bit_buf, 16);
	    bit_buf <<= 16;
	    GETWORD (bit_buf, bits + 16, bit_ptr);
	    i += tab->run;
	    if (i < 64)
		goto normal_code;
	}
	break;	/* illegal, check needed to avoid buffer overflow */
    }
    DUMPBITS (bit_buf, bits, 2);	/* dump end of block code */
    decoder->bitstream_buf = bit_buf;
    decoder->bitstream_bits = bits;
    decoder->bitstream_ptr = bit_ptr;
    return i;
}

static inline void slice_intra_DCT (mpeg2_decoder_t * const decoder,
				    const int cc,
				    uint8_t * const dest, const int stride)
{
#define bit_buf (decoder->bitstream_buf)
#define bits (decoder->bitstream_bits)
#define bit_ptr (decoder->bitstream_ptr)
    NEEDBITS (bit_buf, bits, bit_ptr);
    /* Get the intra DC coefficient and inverse quantize it */
    if (cc == 0)
	decoder->DCTblock[0] =
	    decoder->dc_dct_pred[0] += get_luma_dc_dct_diff (decoder);
    else
	decoder->DCTblock[0] =
	    decoder->dc_dct_pred[cc] += get_chroma_dc_dct_diff (decoder);

    if (decoder->mpeg1) {
	if (decoder->coding_type != D_TYPE)
	    get_mpeg1_intra_block (decoder);
    } else if (decoder->intra_vlc_format)
	get_intra_block_B15 (decoder, decoder->quantizer_matrix[cc ? 2 : 0]);
    else
	get_intra_block_B14 (decoder, decoder->quantizer_matrix[cc ? 2 : 0]);
    mpeg2_idct_copy (decoder->DCTblock, dest, stride);
#undef bit_buf
#undef bits
#undef bit_ptr
}

static inline void slice_non_intra_DCT (mpeg2_decoder_t * const decoder,
					const int cc,
					uint8_t * const dest, const int stride)
{
    int last;

    if (decoder->mpeg1)
	last = get_mpeg1_non_intra_block (decoder);
    else
	last = get_non_intra_block (decoder,
				    decoder->quantizer_matrix[cc ? 3 : 1]);
    mpeg2_idct_add (last, decoder->DCTblock, dest, stride);
}

#define MOTION_420(table,ref,motion_x,motion_y,size,y)			      \
    pos_x = 2 * decoder->offset + motion_x;				      \
    pos_y = 2 * decoder->v_offset + motion_y + 2 * y;			      \
    if (unlikely (pos_x > decoder->limit_x)) {				      \
	pos_x = ((int)pos_x < 0) ? 0 : decoder->limit_x;		      \
	motion_x = pos_x - 2 * decoder->offset;				      \
    }									      \
    if (unlikely (pos_y > decoder->limit_y_ ## size)) {			      \
	pos_y = ((int)pos_y < 0) ? 0 : decoder->limit_y_ ## size;	      \
	motion_y = pos_y - 2 * decoder->v_offset - 2 * y;		      \
    }									      \
    xy_half = ((pos_y & 1) << 1) | (pos_x & 1);				      \
    table[xy_half] (decoder->dest[0] + y * decoder->stride + decoder->offset, \
		    ref[0] + (pos_x >> 1) + (pos_y >> 1) * decoder->stride,   \
		    decoder->stride, size);				      \
    motion_x /= 2;	motion_y /= 2;					      \
    xy_half = ((motion_y & 1) << 1) | (motion_x & 1);			      \
    offset = (((decoder->offset + motion_x) >> 1) +			      \
	      ((((decoder->v_offset + motion_y) >> 1) + y/2) *		      \
	       decoder->uv_stride));					      \
    table[4+xy_half] (decoder->dest[1] + y/2 * decoder->uv_stride +	      \
		      (decoder->offset >> 1), ref[1] + offset,		      \
		      decoder->uv_stride, size/2);			      \
    table[4+xy_half] (decoder->dest[2] + y/2 * decoder->uv_stride +	      \
		      (decoder->offset >> 1), ref[2] + offset,		      \
		      decoder->uv_stride, size/2)

#define MOTION_FIELD_420(table,ref,motion_x,motion_y,dest_field,op,src_field) \
    pos_x = 2 * decoder->offset + motion_x;				      \
    pos_y = decoder->v_offset + motion_y;				      \
    if (unlikely (pos_x > decoder->limit_x)) {				      \
	pos_x = ((int)pos_x < 0) ? 0 : decoder->limit_x;		      \
	motion_x = pos_x - 2 * decoder->offset;				      \
    }									      \
    if (unlikely (pos_y > decoder->limit_y)) {				      \
	pos_y = ((int)pos_y < 0) ? 0 : decoder->limit_y;		      \
	motion_y = pos_y - decoder->v_offset;				      \
    }									      \
    xy_half = ((pos_y & 1) << 1) | (pos_x & 1);				      \
    table[xy_half] (decoder->dest[0] + dest_field * decoder->stride +	      \
		    decoder->offset,					      \
		    (ref[0] + (pos_x >> 1) +				      \
		     ((pos_y op) + src_field) * decoder->stride),	      \
		    2 * decoder->stride, 8);				      \
    motion_x /= 2;	motion_y /= 2;					      \
    xy_half = ((motion_y & 1) << 1) | (motion_x & 1);			      \
    offset = (((decoder->offset + motion_x) >> 1) +			      \
	      (((decoder->v_offset >> 1) + (motion_y op) + src_field) *	      \
	       decoder->uv_stride));					      \
    table[4+xy_half] (decoder->dest[1] + dest_field * decoder->uv_stride +    \
		      (decoder->offset >> 1), ref[1] + offset,		      \
		      2 * decoder->uv_stride, 4);			      \
    table[4+xy_half] (decoder->dest[2] + dest_field * decoder->uv_stride +    \
		      (decoder->offset >> 1), ref[2] + offset,		      \
		      2 * decoder->uv_stride, 4)

#define MOTION_DMV_420(table,ref,motion_x,motion_y)			      \
    pos_x = 2 * decoder->offset + motion_x;				      \
    pos_y = decoder->v_offset + motion_y;				      \
    if (unlikely (pos_x > decoder->limit_x)) {				      \
	pos_x = ((int)pos_x < 0) ? 0 : decoder->limit_x;		      \
	motion_x = pos_x - 2 * decoder->offset;				      \
    }									      \
    if (unlikely (pos_y > decoder->limit_y)) {				      \
	pos_y = ((int)pos_y < 0) ? 0 : decoder->limit_y;		      \
	motion_y = pos_y - decoder->v_offset;				      \
    }									      \
    xy_half = ((pos_y & 1) << 1) | (pos_x & 1);				      \
    offset = (pos_x >> 1) + (pos_y & ~1) * decoder->stride;		      \
    table[xy_half] (decoder->dest[0] + decoder->offset,			      \
		    ref[0] + offset, 2 * decoder->stride, 8);		      \
    table[xy_half] (decoder->dest[0] + decoder->stride + decoder->offset,     \
		    ref[0] + decoder->stride + offset,			      \
		    2 * decoder->stride, 8);				      \
    motion_x /= 2;	motion_y /= 2;					      \
    xy_half = ((motion_y & 1) << 1) | (motion_x & 1);			      \
    offset = (((decoder->offset + motion_x) >> 1) +			      \
	      (((decoder->v_offset >> 1) + (motion_y & ~1)) *		      \
	       decoder->uv_stride));					      \
    table[4+xy_half] (decoder->dest[1] + (decoder->offset >> 1),	      \
		      ref[1] + offset, 2 * decoder->uv_stride, 4);	      \
    table[4+xy_half] (decoder->dest[1] + decoder->uv_stride +		      \
		      (decoder->offset >> 1),				      \
		      ref[1] + decoder->uv_stride + offset,		      \
		      2 * decoder->uv_stride, 4);			      \
    table[4+xy_half] (decoder->dest[2] + (decoder->offset >> 1),	      \
		      ref[2] + offset, 2 * decoder->uv_stride, 4);	      \
    table[4+xy_half] (decoder->dest[2] + decoder->uv_stride +		      \
		      (decoder->offset >> 1),				      \
		      ref[2] + decoder->uv_stride + offset,		      \
		      2 * decoder->uv_stride, 4)

#define MOTION_ZERO_420(table,ref)					      \
    table[0] (decoder->dest[0] + decoder->offset,			      \
	      (ref[0] + decoder->offset +				      \
	       decoder->v_offset * decoder->stride), decoder->stride, 16);    \
    offset = ((decoder->offset >> 1) +					      \
	      (decoder->v_offset >> 1) * decoder->uv_stride);		      \
    table[4] (decoder->dest[1] + (decoder->offset >> 1),		      \
	      ref[1] + offset, decoder->uv_stride, 8);			      \
    table[4] (decoder->dest[2] + (decoder->offset >> 1),		      \
	      ref[2] + offset, decoder->uv_stride, 8)

#define MOTION_422(table,ref,motion_x,motion_y,size,y)			      \
    pos_x = 2 * decoder->offset + motion_x;				      \
    pos_y = 2 * decoder->v_offset + motion_y + 2 * y;			      \
    if (unlikely (pos_x > decoder->limit_x)) {				      \
	pos_x = ((int)pos_x < 0) ? 0 : decoder->limit_x;		      \
	motion_x = pos_x - 2 * decoder->offset;				      \
    }									      \
    if (unlikely (pos_y > decoder->limit_y_ ## size)) {			      \
	pos_y = ((int)pos_y < 0) ? 0 : decoder->limit_y_ ## size;	      \
	motion_y = pos_y - 2 * decoder->v_offset - 2 * y;		      \
    }									      \
    xy_half = ((pos_y & 1) << 1) | (pos_x & 1);				      \
    offset = (pos_x >> 1) + (pos_y >> 1) * decoder->stride;		      \
    table[xy_half] (decoder->dest[0] + y * decoder->stride + decoder->offset, \
		    ref[0] + offset, decoder->stride, size);		      \
    offset = (offset + (motion_x & (motion_x < 0))) >> 1;		      \
    motion_x /= 2;							      \
    xy_half = ((pos_y & 1) << 1) | (motion_x & 1);			      \
    table[4+xy_half] (decoder->dest[1] + y * decoder->uv_stride +	      \
		      (decoder->offset >> 1), ref[1] + offset,		      \
		      decoder->uv_stride, size);			      \
    table[4+xy_half] (decoder->dest[2] + y * decoder->uv_stride +	      \
		      (decoder->offset >> 1), ref[2] + offset,		      \
		      decoder->uv_stride, size)

#define MOTION_FIELD_422(table,ref,motion_x,motion_y,dest_field,op,src_field) \
    pos_x = 2 * decoder->offset + motion_x;				      \
    pos_y = decoder->v_offset + motion_y;				      \
    if (unlikely (pos_x > decoder->limit_x)) {				      \
	pos_x = ((int)pos_x < 0) ? 0 : decoder->limit_x;		      \
	motion_x = pos_x - 2 * decoder->offset;				      \
    }									      \
    if (unlikely (pos_y > decoder->limit_y)) {				      \
	pos_y = ((int)pos_y < 0) ? 0 : decoder->limit_y;		      \
	motion_y = pos_y - decoder->v_offset;				      \
    }									      \
    xy_half = ((pos_y & 1) << 1) | (pos_x & 1);				      \
    offset = (pos_x >> 1) + ((pos_y op) + src_field) * decoder->stride;	      \
    table[xy_half] (decoder->dest[0] + dest_field * decoder->stride +	      \
		    decoder->offset, ref[0] + offset,			      \
		    2 * decoder->stride, 8);				      \
    offset = (offset + (motion_x & (motion_x < 0))) >> 1;		      \
    motion_x /= 2;							      \
    xy_half = ((pos_y & 1) << 1) | (motion_x & 1);			      \
    table[4+xy_half] (decoder->dest[1] + dest_field * decoder->uv_stride +    \
		      (decoder->offset >> 1), ref[1] + offset,		      \
		      2 * decoder->uv_stride, 8);			      \
    table[4+xy_half] (decoder->dest[2] + dest_field * decoder->uv_stride +    \
		      (decoder->offset >> 1), ref[2] + offset,		      \
		      2 * decoder->uv_stride, 8)

#define MOTION_DMV_422(table,ref,motion_x,motion_y)			      \
    pos_x = 2 * decoder->offset + motion_x;				      \
    pos_y = decoder->v_offset + motion_y;				      \
    if (unlikely (pos_x > decoder->limit_x)) {				      \
	pos_x = ((int)pos_x < 0) ? 0 : decoder->limit_x;		      \
	motion_x = pos_x - 2 * decoder->offset;				      \
    }									      \
    if (unlikely (pos_y > decoder->limit_y)) {				      \
	pos_y = ((int)pos_y < 0) ? 0 : decoder->limit_y;		      \
	motion_y = pos_y - decoder->v_offset;				      \
    }									      \
    xy_half = ((pos_y & 1) << 1) | (pos_x & 1);				      \
    offset = (pos_x >> 1) + (pos_y & ~1) * decoder->stride;		      \
    table[xy_half] (decoder->dest[0] + decoder->offset,			      \
		    ref[0] + offset, 2 * decoder->stride, 8);		      \
    table[xy_half] (decoder->dest[0] + decoder->stride + decoder->offset,     \
		    ref[0] + decoder->stride + offset,			      \
		    2 * decoder->stride, 8);				      \
    offset = (offset + (motion_x & (motion_x < 0))) >> 1;		      \
    motion_x /= 2;							      \
    xy_half = ((pos_y & 1) << 1) | (motion_x & 1);			      \
    table[4+xy_half] (decoder->dest[1] + (decoder->offset >> 1),	      \
		      ref[1] + offset, 2 * decoder->uv_stride, 8);	      \
    table[4+xy_half] (decoder->dest[1] + decoder->uv_stride +		      \
		      (decoder->offset >> 1),				      \
		      ref[1] + decoder->uv_stride + offset,		      \
		      2 * decoder->uv_stride, 8);			      \
    table[4+xy_half] (decoder->dest[2] + (decoder->offset >> 1),	      \
		      ref[2] + offset, 2 * decoder->uv_stride, 8);	      \
    table[4+xy_half] (decoder->dest[2] + decoder->uv_stride +		      \
		      (decoder->offset >> 1),				      \
		      ref[2] + decoder->uv_stride + offset,		      \
		      2 * decoder->uv_stride, 8)

#define MOTION_ZERO_422(table,ref)					      \
    offset = decoder->offset + decoder->v_offset * decoder->stride;	      \
    table[0] (decoder->dest[0] + decoder->offset,			      \