ffmpeg/libavcodec/mpegvideo.h

627 lines
24 KiB
C

/*
* Generic DCT based hybrid video encoder
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
* Copyright (c) 2002-2004 Michael Niedermayer
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* mpegvideo header.
*/
#ifndef AVCODEC_MPEGVIDEO_H
#define AVCODEC_MPEGVIDEO_H
#include "blockdsp.h"
#include "error_resilience.h"
#include "fdctdsp.h"
#include "get_bits.h"
#include "h264chroma.h"
#include "h263dsp.h"
#include "hpeldsp.h"
#include "idctdsp.h"
#include "me_cmp.h"
#include "motion_est.h"
#include "mpegpicture.h"
#include "mpegvideoencdsp.h"
#include "pixblockdsp.h"
#include "put_bits.h"
#include "ratecontrol.h"
#include "qpeldsp.h"
#include "videodsp.h"
#define MAX_THREADS 32
#define MAX_B_FRAMES 16
/**
* Scantable.
*/
typedef struct ScanTable {
const uint8_t *scantable;
uint8_t permutated[64];
uint8_t raster_end[64];
} ScanTable;
enum OutputFormat {
FMT_MPEG1,
FMT_H261,
FMT_H263,
FMT_MJPEG,
FMT_SPEEDHQ,
};
/**
* MpegEncContext.
*/
typedef struct MpegEncContext {
AVClass *class;
int y_dc_scale, c_dc_scale;
int ac_pred;
int block_last_index[12]; ///< last non zero coefficient in block
int h263_aic; ///< Advanced INTRA Coding (AIC)
/* scantables */
ScanTable inter_scantable; ///< if inter == intra then intra should be used to reduce the cache usage
/* WARNING: changes above this line require updates to hardcoded
* offsets used in ASM. */
ScanTable intra_scantable;
uint8_t permutated_intra_h_scantable[64];
uint8_t permutated_intra_v_scantable[64];
struct AVCodecContext *avctx;
/* The following pointer is intended for codecs sharing code
* between decoder and encoder and in need of a common context to do so. */
void *private_ctx;
/* the following parameters must be initialized before encoding */
int width, height;///< picture size. must be a multiple of 16
int gop_size;
int intra_only; ///< if true, only intra pictures are generated
int64_t bit_rate; ///< wanted bit rate
enum OutputFormat out_format; ///< output format
int h263_pred; ///< use MPEG-4/H.263 ac/dc predictions
int pb_frame; ///< PB-frame mode (0 = none, 1 = base, 2 = improved)
/* the following codec id fields are deprecated in favor of codec_id */
int h263_plus; ///< H.263+ headers
int h263_flv; ///< use flv H.263 header
enum AVCodecID codec_id; /* see AV_CODEC_ID_xxx */
int fixed_qscale; ///< fixed qscale if non zero
int encoding; ///< true if we are encoding (vs decoding)
int max_b_frames; ///< max number of B-frames for encoding
int luma_elim_threshold;
int chroma_elim_threshold;
int workaround_bugs; ///< workaround bugs in encoders which cannot be detected automatically
int codec_tag; ///< internal codec_tag upper case converted from avctx codec_tag
/* the following fields are managed internally by the encoder */
/* sequence parameters */
int context_initialized;
int input_picture_number; ///< used to set pic->display_picture_number, should not be used for/by anything else
int coded_picture_number; ///< used to set pic->coded_picture_number, should not be used for/by anything else
int picture_number; //FIXME remove, unclear definition
int picture_in_gop_number; ///< 0-> first pic in gop, ...
int mb_width, mb_height; ///< number of MBs horizontally & vertically
int mb_stride; ///< mb_width+1 used for some arrays to allow simple addressing of left & top MBs without sig11
int b8_stride; ///< 2*mb_width+1 used for some 8x8 block arrays to allow simple addressing
int h_edge_pos, v_edge_pos;///< horizontal / vertical position of the right/bottom edge (pixel replication)
int mb_num; ///< number of MBs of a picture
ptrdiff_t linesize; ///< line size, in bytes, may be different from width
ptrdiff_t uvlinesize; ///< line size, for chroma in bytes, may be different from width
struct FFRefStructPool *picture_pool; ///< Pool for MPVPictures
MPVPicture **input_picture;///< next pictures on display order for encoding
MPVPicture **reordered_input_picture; ///< pointer to the next pictures in coded order for encoding
BufferPoolContext buffer_pools;
int64_t user_specified_pts; ///< last non-zero pts from AVFrame which was passed into avcodec_send_frame()
/**
* pts difference between the first and second input frame, used for
* calculating dts of the first frame when there's a delay */
int64_t dts_delta;
/**
* reordered pts to be used as dts for the next output frame when there's
* a delay */
int64_t reordered_pts;
/** bit output */
PutBitContext pb;
int start_mb_y; ///< start mb_y of this thread (so current thread should process start_mb_y <= row < end_mb_y)
int end_mb_y; ///< end mb_y of this thread (so current thread should process start_mb_y <= row < end_mb_y)
struct MpegEncContext *thread_context[MAX_THREADS];
int slice_context_count; ///< number of used thread_contexts
/**
* copy of the previous picture structure.
* note, linesize & data, might not match the previous picture (for field pictures)
*/
MPVWorkPicture last_pic;
/**
* copy of the next picture structure.
* note, linesize & data, might not match the next picture (for field pictures)
*/
MPVWorkPicture next_pic;
/**
* Reference to the source picture for encoding.
* note, linesize & data, might not match the source picture (for field pictures)
*/
AVFrame *new_pic;
/**
* copy of the current picture structure.
* note, linesize & data, might not match the current picture (for field pictures)
*/
MPVWorkPicture cur_pic;
int skipped_last_frame;
int last_dc[3]; ///< last DC values for MPEG-1
int16_t *dc_val_base;
int16_t *dc_val[3]; ///< used for MPEG-4 DC prediction, all 3 arrays must be continuous
const uint8_t *y_dc_scale_table; ///< qscale -> y_dc_scale table
const uint8_t *c_dc_scale_table; ///< qscale -> c_dc_scale table
const uint8_t *chroma_qscale_table; ///< qscale -> chroma_qscale (H.263)
uint8_t *coded_block_base;
uint8_t *coded_block; ///< used for coded block pattern prediction (msmpeg4v3, wmv1)
int16_t (*ac_val_base)[16];
int16_t (*ac_val[3])[16]; ///< used for MPEG-4 AC prediction, all 3 arrays must be continuous
int mb_skipped; ///< MUST BE SET only during DECODING
uint8_t *mbskip_table; /**< used to avoid copy if macroblock skipped (for black regions for example)
and used for B-frame encoding & decoding (contains skip table of next P-frame) */
uint8_t *mbintra_table; ///< used to avoid setting {ac, dc, cbp}-pred stuff to zero on inter MB decoding
uint8_t *cbp_table; ///< used to store cbp, ac_pred for partitioned decoding
uint8_t *pred_dir_table; ///< used to store pred_dir for partitioned decoding
ScratchpadContext sc;
int qscale; ///< QP
int chroma_qscale; ///< chroma QP
unsigned int lambda; ///< Lagrange multiplier used in rate distortion
unsigned int lambda2; ///< (lambda*lambda) >> FF_LAMBDA_SHIFT
int *lambda_table;
int adaptive_quant; ///< use adaptive quantization
int dquant; ///< qscale difference to prev qscale
int pict_type; ///< AV_PICTURE_TYPE_I, AV_PICTURE_TYPE_P, AV_PICTURE_TYPE_B, ...
int vbv_delay;
int last_pict_type; //FIXME removes
int last_non_b_pict_type; ///< used for MPEG-4 gmc B-frames & ratecontrol
int droppable;
int last_lambda_for[5]; ///< last lambda for a specific pict type
int skipdct; ///< skip dct and code zero residual
/* motion compensation */
int unrestricted_mv; ///< mv can point outside of the coded picture
int h263_long_vectors; ///< use horrible H.263v1 long vector mode
BlockDSPContext bdsp;
FDCTDSPContext fdsp;
H264ChromaContext h264chroma;
HpelDSPContext hdsp;
IDCTDSPContext idsp;
MpegvideoEncDSPContext mpvencdsp;
PixblockDSPContext pdsp;
QpelDSPContext qdsp;
VideoDSPContext vdsp;
H263DSPContext h263dsp;
int f_code; ///< forward MV resolution
int b_code; ///< backward MV resolution for B-frames (MPEG-4)
int16_t (*p_mv_table_base)[2];
int16_t (*b_forw_mv_table_base)[2];
int16_t (*b_back_mv_table_base)[2];
int16_t (*b_bidir_forw_mv_table_base)[2];
int16_t (*b_bidir_back_mv_table_base)[2];
int16_t (*b_direct_mv_table_base)[2];
int16_t (*p_field_mv_table_base)[2];
int16_t (*b_field_mv_table_base)[2];
int16_t (*p_mv_table)[2]; ///< MV table (1MV per MB) P-frame encoding
int16_t (*b_forw_mv_table)[2]; ///< MV table (1MV per MB) forward mode B-frame encoding
int16_t (*b_back_mv_table)[2]; ///< MV table (1MV per MB) backward mode B-frame encoding
int16_t (*b_bidir_forw_mv_table)[2]; ///< MV table (1MV per MB) bidir mode B-frame encoding
int16_t (*b_bidir_back_mv_table)[2]; ///< MV table (1MV per MB) bidir mode B-frame encoding
int16_t (*b_direct_mv_table)[2]; ///< MV table (1MV per MB) direct mode B-frame encoding
int16_t (*p_field_mv_table[2][2])[2]; ///< MV table (2MV per MB) interlaced P-frame encoding
int16_t (*b_field_mv_table[2][2][2])[2];///< MV table (4MV per MB) interlaced B-frame encoding
uint8_t (*p_field_select_table[2]); ///< Only the first element is allocated
uint8_t (*b_field_select_table[2][2]); ///< Only the first element is allocated
/* The following fields are encoder-only */
uint16_t *mb_var; ///< Table for MB variances
uint16_t *mc_mb_var; ///< Table for motion compensated MB variances
uint8_t *mb_mean; ///< Table for MB luminance
int64_t mb_var_sum; ///< sum of MB variance for current frame
int64_t mc_mb_var_sum; ///< motion compensated MB variance for current frame
uint64_t encoding_error[MPV_MAX_PLANES];
int motion_est; ///< ME algorithm
int me_penalty_compensation;
int me_pre; ///< prepass for motion estimation
int mv_dir;
#define MV_DIR_FORWARD 1
#define MV_DIR_BACKWARD 2
#define MV_DIRECT 4 ///< bidirectional mode where the difference equals the MV of the last P/S/I-Frame (MPEG-4)
int mv_type;
#define MV_TYPE_16X16 0 ///< 1 vector for the whole mb
#define MV_TYPE_8X8 1 ///< 4 vectors (H.263, MPEG-4 4MV)
#define MV_TYPE_16X8 2 ///< 2 vectors, one per 16x8 block
#define MV_TYPE_FIELD 3 ///< 2 vectors, one per field
#define MV_TYPE_DMV 4 ///< 2 vectors, special mpeg2 Dual Prime Vectors
/**motion vectors for a macroblock
first coordinate : 0 = forward 1 = backward
second " : depend on type
third " : 0 = x, 1 = y
*/
int mv[2][4][2];
int field_select[2][2];
int last_mv[2][2][2]; ///< last MV, used for MV prediction in MPEG-1 & B-frame MPEG-4
const uint8_t *fcode_tab; ///< smallest fcode needed for each MV
int16_t direct_scale_mv[2][64]; ///< precomputed to avoid divisions in ff_mpeg4_set_direct_mv
MotionEstContext me;
int no_rounding; /**< apply no rounding to motion compensation (MPEG-4, msmpeg4, ...)
for B-frames rounding mode is always 0 */
/* macroblock layer */
int mb_x, mb_y;
int mb_skip_run;
int mb_intra;
uint16_t *mb_type; ///< Table for candidate MB types for encoding (defines in mpegvideoenc.h)
int block_index[6]; ///< index to current MB in block based arrays with edges
int block_wrap[6];
uint8_t *dest[3];
int *mb_index2xy; ///< mb_index -> mb_x + mb_y*mb_stride
/** matrix transmitted in the bitstream */
uint16_t intra_matrix[64];
uint16_t chroma_intra_matrix[64];
uint16_t inter_matrix[64];
uint16_t chroma_inter_matrix[64];
int intra_quant_bias; ///< bias for the quantizer
int inter_quant_bias; ///< bias for the quantizer
int min_qcoeff; ///< minimum encodable coefficient
int max_qcoeff; ///< maximum encodable coefficient
int ac_esc_length; ///< num of bits needed to encode the longest esc
uint8_t *intra_ac_vlc_length;
uint8_t *intra_ac_vlc_last_length;
uint8_t *intra_chroma_ac_vlc_length;
uint8_t *intra_chroma_ac_vlc_last_length;
uint8_t *inter_ac_vlc_length;
uint8_t *inter_ac_vlc_last_length;
uint8_t *luma_dc_vlc_length;
int coded_score[12];
/** precomputed matrix (combine qscale and DCT renorm) */
int (*q_intra_matrix)[64];
int (*q_chroma_intra_matrix)[64];
int (*q_inter_matrix)[64];
/** identical to the above but for MMX & these are not permutated, second 64 entries are bias*/
uint16_t (*q_intra_matrix16)[2][64];
uint16_t (*q_chroma_intra_matrix16)[2][64];
uint16_t (*q_inter_matrix16)[2][64];
/* noise reduction */
int (*dct_error_sum)[64];
int dct_count[2];
uint16_t (*dct_offset)[64];
/* bit rate control */
int64_t total_bits;
int frame_bits; ///< bits used for the current frame
int stuffing_bits; ///< bits used for stuffing
int next_lambda; ///< next lambda used for retrying to encode a frame
RateControlContext rc_context; ///< contains stuff only accessed in ratecontrol.c
/* statistics, used for 2-pass encoding */
int mv_bits;
int header_bits;
int i_tex_bits;
int p_tex_bits;
int i_count;
int misc_bits; ///< cbp, mb_type
int last_bits; ///< temp var used for calculating the above vars
/* error concealment / resync */
int resync_mb_x; ///< x position of last resync marker
int resync_mb_y; ///< y position of last resync marker
GetBitContext last_resync_gb; ///< used to search for the next resync marker
int mb_num_left; ///< number of MBs left in this video packet (for partitioned Slices only)
/* H.263 specific */
int gob_index;
int obmc; ///< overlapped block motion compensation
int mb_info; ///< interval for outputting info about mb offsets as side data
int prev_mb_info, last_mb_info;
uint8_t *mb_info_ptr;
int mb_info_size;
int ehc_mode;
/* H.263+ specific */
int umvplus; ///< == H.263+ && unrestricted_mv
int h263_aic_dir; ///< AIC direction: 0 = left, 1 = top
int h263_slice_structured;
int alt_inter_vlc; ///< alternative inter vlc
int modified_quant;
int loop_filter;
int custom_pcf;
/* MPEG-4 specific */
int studio_profile;
int dct_precision;
///< number of bits to represent the fractional part of time (encoder only)
int time_increment_bits;
int last_time_base;
int time_base; ///< time in seconds of last I,P,S Frame
int64_t time; ///< time of current frame
int64_t last_non_b_time;
uint16_t pp_time; ///< time distance between the last 2 p,s,i frames
uint16_t pb_time; ///< time distance between the last b and p,s,i frame
uint16_t pp_field_time;
uint16_t pb_field_time; ///< like above, just for interlaced
int mcsel;
int quarter_sample; ///< 1->qpel, 0->half pel ME/MC
int data_partitioning; ///< data partitioning flag from header
int partitioned_frame; ///< is current frame partitioned
int low_delay; ///< no reordering needed / has no B-frames
PutBitContext tex_pb; ///< used for data partitioned VOPs
PutBitContext pb2; ///< used for data partitioned VOPs
int mpeg_quant;
int padding_bug_score; ///< used to detect the VERY common padding bug in MPEG-4
/* divx specific, used to workaround (many) bugs in divx5 */
int divx_packed;
uint8_t *bitstream_buffer; //Divx 5.01 puts several frames in a single one, this is used to reorder them
int bitstream_buffer_size;
unsigned int allocated_bitstream_buffer_size;
/* RV10 specific */
int rv10_version; ///< RV10 version: 0 or 3
int rv10_first_dc_coded[3];
/* MJPEG specific */
struct MJpegContext *mjpeg_ctx;
int esc_pos;
/* MSMPEG4 specific */
int mv_table_index;
int rl_table_index;
int rl_chroma_table_index;
int dc_table_index;
int use_skip_mb_code;
int slice_height; ///< in macroblocks
int first_slice_line; ///< used in MPEG-4 too to handle resync markers
int flipflop_rounding;
enum {
MSMP4_UNUSED,
MSMP4_V1,
MSMP4_V2,
MSMP4_V3,
MSMP4_WMV1,
MSMP4_WMV2,
MSMP4_VC1, ///< for VC1 (image), WMV3 (image) and MSS2.
} msmpeg4_version;
int per_mb_rl_table;
int esc3_level_length;
int esc3_run_length;
int inter_intra_pred;
int mspel;
/* decompression specific */
GetBitContext gb;
/* MPEG-1 specific */
int last_mv_dir; ///< last mv_dir, used for B-frame encoding
int vbv_delay_pos; ///< offset of vbv_delay in the bitstream
/* MPEG-2-specific - I wished not to have to support this mess. */
int progressive_sequence;
int mpeg_f_code[2][2];
// picture structure defines are loaded from mpegutils.h
int picture_structure;
int intra_dc_precision;
int frame_pred_frame_dct;
int top_field_first;
int concealment_motion_vectors;
int q_scale_type;
int brd_scale;
int intra_vlc_format;
int alternate_scan;
int repeat_first_field;
int chroma_420_type;
int chroma_format;
#define CHROMA_420 1
#define CHROMA_422 2
#define CHROMA_444 3
int chroma_x_shift;//depend on pix_format, that depend on chroma_format
int chroma_y_shift;
int progressive_frame;
int full_pel[2];
int interlaced_dct;
int first_field; ///< is 1 for the first field of a field picture 0 otherwise
/* RTP specific */
int rtp_mode;
int rtp_payload_size;
uint8_t *ptr_lastgob;
int16_t (*block)[64]; ///< points to one of the following blocks
int16_t (*blocks)[12][64]; // for HQ mode we need to keep the best block
int (*decode_mb)(struct MpegEncContext *s, int16_t block[12][64]); // used by some codecs to avoid a switch()
#define SLICE_OK 0
#define SLICE_ERROR -1
#define SLICE_END -2 ///<end marker found
#define SLICE_NOEND -3 ///<no end marker or error found but mb count exceeded
void (*dct_unquantize_mpeg1_intra)(struct MpegEncContext *s,
int16_t *block/*align 16*/, int n, int qscale);
void (*dct_unquantize_mpeg1_inter)(struct MpegEncContext *s,
int16_t *block/*align 16*/, int n, int qscale);
void (*dct_unquantize_mpeg2_intra)(struct MpegEncContext *s,
int16_t *block/*align 16*/, int n, int qscale);
void (*dct_unquantize_mpeg2_inter)(struct MpegEncContext *s,
int16_t *block/*align 16*/, int n, int qscale);
void (*dct_unquantize_h263_intra)(struct MpegEncContext *s,
int16_t *block/*align 16*/, int n, int qscale);
void (*dct_unquantize_h263_inter)(struct MpegEncContext *s,
int16_t *block/*align 16*/, int n, int qscale);
void (*dct_unquantize_intra)(struct MpegEncContext *s, // unquantizer to use (MPEG-4 can use both)
int16_t *block/*align 16*/, int n, int qscale);
void (*dct_unquantize_inter)(struct MpegEncContext *s, // unquantizer to use (MPEG-4 can use both)
int16_t *block/*align 16*/, int n, int qscale);
int (*dct_quantize)(struct MpegEncContext *s, int16_t *block/*align 16*/, int n, int qscale, int *overflow);
void (*denoise_dct)(struct MpegEncContext *s, int16_t *block);
int mpv_flags; ///< flags set by private options
int quantizer_noise_shaping;
me_cmp_func ildct_cmp[2]; ///< 0 = intra, 1 = non-intra
me_cmp_func n_sse_cmp[2]; ///< either SSE or NSSE cmp func
me_cmp_func sad_cmp[2];
me_cmp_func sse_cmp[2];
int (*sum_abs_dctelem)(const int16_t *block);
/**
* ratecontrol qmin qmax limiting method
* 0-> clipping, 1-> use a nice continuous function to limit qscale within qmin/qmax.
*/
float rc_qsquish;
float rc_qmod_amp;
int rc_qmod_freq;
float rc_initial_cplx;
float rc_buffer_aggressivity;
float border_masking;
int lmin, lmax;
int vbv_ignore_qmax;
char *rc_eq;
/* temp buffers for rate control */
float *cplx_tab, *bits_tab;
/* flag to indicate a reinitialization is required, e.g. after
* a frame size change */
int context_reinit;
ERContext er;
int error_rate;
/* temporary frames used by b_frame_strategy = 2 */
AVFrame *tmp_frames[MAX_B_FRAMES + 2];
int b_frame_strategy;
int b_sensitivity;
/* frame skip options for encoding */
int frame_skip_threshold;
int frame_skip_factor;
int frame_skip_exp;
int frame_skip_cmp;
me_cmp_func frame_skip_cmp_fn;
int scenechange_threshold;
int noise_reduction;
int intra_penalty;
} MpegEncContext;
/**
* Set the given MpegEncContext to common defaults (same for encoding
* and decoding). The changed fields will not depend upon the prior
* state of the MpegEncContext.
*/
void ff_mpv_common_defaults(MpegEncContext *s);
int ff_mpv_common_init(MpegEncContext *s);
void ff_mpv_common_init_arm(MpegEncContext *s);
void ff_mpv_common_init_axp(MpegEncContext *s);
void ff_mpv_common_init_neon(MpegEncContext *s);
void ff_mpv_common_init_ppc(MpegEncContext *s);
void ff_mpv_common_init_x86(MpegEncContext *s);
void ff_mpv_common_init_mips(MpegEncContext *s);
/**
* Initialize an MpegEncContext's thread contexts. Presumes that
* slice_context_count is already set and that all the fields
* that are freed/reset in free_duplicate_context() are NULL.
*/
int ff_mpv_init_duplicate_contexts(MpegEncContext *s);
/**
* Initialize and allocates MpegEncContext fields dependent on the resolution.
*/
int ff_mpv_init_context_frame(MpegEncContext *s);
/**
* Frees and resets MpegEncContext fields depending on the resolution
* as well as the slice thread contexts.
* Is used during resolution changes to avoid a full reinitialization of the
* codec.
*/
void ff_mpv_free_context_frame(MpegEncContext *s);
void ff_mpv_common_end(MpegEncContext *s);
void ff_clean_intra_table_entries(MpegEncContext *s);
int ff_update_duplicate_context(MpegEncContext *dst, const MpegEncContext *src);
void ff_set_qscale(MpegEncContext * s, int qscale);
void ff_mpv_idct_init(MpegEncContext *s);
void ff_init_scantable(const uint8_t *permutation, ScanTable *st,
const uint8_t *src_scantable);
void ff_init_block_index(MpegEncContext *s);
void ff_mpv_motion(MpegEncContext *s,
uint8_t *dest_y, uint8_t *dest_cb,
uint8_t *dest_cr, int dir,
uint8_t *const *ref_picture,
const op_pixels_func (*pix_op)[4],
const qpel_mc_func (*qpix_op)[16]);
static inline void ff_update_block_index(MpegEncContext *s, int bits_per_raw_sample,
int lowres, int chroma_x_shift)
{
const int bytes_per_pixel = 1 + (bits_per_raw_sample > 8);
const int block_size = (8 * bytes_per_pixel) >> lowres;
s->block_index[0]+=2;
s->block_index[1]+=2;
s->block_index[2]+=2;
s->block_index[3]+=2;
s->block_index[4]++;
s->block_index[5]++;
s->dest[0]+= 2*block_size;
s->dest[1] += (2 >> chroma_x_shift) * block_size;
s->dest[2] += (2 >> chroma_x_shift) * block_size;
}
#endif /* AVCODEC_MPEGVIDEO_H */