mpegvideo.h

手机端的H264源码

/*
 * Generic DCT based hybrid video encoder
 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard.
 * Copyright (c) 2002-2004 Michael Niedermayer
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/**
 * @file mpegvideo.h
 * mpegvideo header.
 */
 
#ifndef AVCODEC_MPEGVIDEO_H
#define AVCODEC_MPEGVIDEO_H

#include "dsputil.h"

#define FRAME_SKIPED 100 ///< return value for header parsers if frame is not coded

enum OutputFormat {
    FMT_MPEG1,
    FMT_H263,
    FMT_MJPEG, 
    FMT_H264,
};

#define EDGE_WIDTH 16

#define MPEG_BUF_SIZE (16 * 1024)

#define QMAT_SHIFT_MMX 16
#define QMAT_SHIFT 22

#define MAX_FCODE 7
#define MAX_MV 2048

#define MAX_THREADS 8

#define MAX_PICTURE_COUNT 15

#define ME_MAP_SIZE 64
#define ME_MAP_SHIFT 3
#define ME_MAP_MV_BITS 11

/* run length table */
#define MAX_RUN    64
#define MAX_LEVEL  64

#define I_TYPE FF_I_TYPE  ///< Intra
#define P_TYPE FF_P_TYPE  ///< Predicted
#define B_TYPE FF_B_TYPE  ///< Bi-dir predicted
#define S_TYPE FF_S_TYPE  ///< S(GMC)-VOP MPEG4
#define SI_TYPE FF_SI_TYPE  ///< Switching Intra
#define SP_TYPE FF_SP_TYPE  ///< Switching Predicted

/**
 * Scantable.
 */
typedef struct ScanTable{
    const uint8_t *scantable;
    uint8_t permutated[64];
    uint8_t raster_end[64];
#ifdef ARCH_POWERPC
		/** Used by dct_quantise_alitvec to find last-non-zero */
    uint8_t __align8 inverse[64];
#endif
} ScanTable;

/**
 * Picture.
 */
typedef struct Picture{
    FF_COMMON_FRAME

    /**
     * halfpel luma planes.
     */
    uint8_t *interpolated[3];
    int16_t (*motion_val_base[2])[2];
    int8_t *ref_index[2];
    uint32_t *mb_type_base;
#define MB_TYPE_INTRA MB_TYPE_INTRA4x4 //default mb_type if theres just one type
#define IS_INTRA4x4(a)   ((a)&MB_TYPE_INTRA4x4)
#define IS_INTRA16x16(a) ((a)&MB_TYPE_INTRA16x16)
#define IS_PCM(a)        ((a)&MB_TYPE_INTRA_PCM)
#define IS_INTRA(a)      ((a)&7)
#define IS_INTER(a)      ((a)&(MB_TYPE_16x16|MB_TYPE_16x8|MB_TYPE_8x16|MB_TYPE_8x8))
#define IS_SKIP(a)       ((a)&MB_TYPE_SKIP)
#define IS_INTRA_PCM(a)  ((a)&MB_TYPE_INTRA_PCM)
#define IS_INTERLACED(a) ((a)&MB_TYPE_INTERLACED)
#define IS_DIRECT(a)     ((a)&MB_TYPE_DIRECT2)
#define IS_GMC(a)        ((a)&MB_TYPE_GMC)
#define IS_16X16(a)      ((a)&MB_TYPE_16x16)
#define IS_16X8(a)       ((a)&MB_TYPE_16x8)
#define IS_8X16(a)       ((a)&MB_TYPE_8x16)
#define IS_8X8(a)        ((a)&MB_TYPE_8x8)
#define IS_SUB_8X8(a)    ((a)&MB_TYPE_16x16) //note reused
#define IS_SUB_8X4(a)    ((a)&MB_TYPE_16x8)  //note reused
#define IS_SUB_4X8(a)    ((a)&MB_TYPE_8x16)  //note reused
#define IS_SUB_4X4(a)    ((a)&MB_TYPE_8x8)   //note reused
#define IS_ACPRED(a)     ((a)&MB_TYPE_ACPRED)
#define IS_QUANT(a)      ((a)&MB_TYPE_QUANT)
#define IS_DIR(a, part, list) ((a) & (MB_TYPE_P0L0<<((part)+2*(list))))
#define USES_LIST(a, list) ((a) & ((MB_TYPE_P0L0|MB_TYPE_P1L0)<<(2*(list)))) ///< does this mb use listX, note doesnt work if subMBs
#define HAS_CBP(a)        ((a)&MB_TYPE_CBP)

    int field_poc[2];           ///< h264 top/bottom POC
    int poc;                    ///< h264 frame POC
    int frame_num;              ///< h264 frame_num
    int pic_id;                 ///< h264 pic_num or long_term_pic_idx
    int long_ref;               ///< 1->long term reference 0->short term reference

    
} Picture;

typedef struct ParseContext{
    uint8_t *buffer;
    int index;
    int last_index;
    int buffer_size;
    uint32_t state;             ///< contains the last few bytes in MSB order
    int frame_start_found;
    int overread;               ///< the number of bytes which where irreversibly read from the next frame
    int overread_index;         ///< the index into ParseContext.buffer of the overreaded bytes
} ParseContext;

struct MpegEncContext;

/**
 * MpegEncContext.
 */
typedef struct MpegEncContext {
    struct AVCodecContext *avctx;
    /* 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 
    int bit_rate;     ///< wanted bit rate 
    enum OutputFormat out_format; ///< output format 
    
    
    int codec_id;     /* see CODEC_ID_xxx */
    int fixed_qscale; ///< fixed qscale if non zero 
    int encoding;     ///< true if we are encoding (vs decoding) 
    int flags;        ///< AVCodecContext.flags (HQ, MV4, ...) 
    int flags2;       ///< AVCodecContext.flags2
    int max_b_frames; ///< max number of b-frames for encoding 
    int luma_elim_threshold;
    int chroma_elim_threshold;
    int strict_std_compliance; ///< strictly follow the std (MPEG4, ...) 
    int workaround_bugs;       ///< workaround bugs in encoders which cannot be detected automatically 
    /* the following fields are managed internally by the encoder */

    /** bit output */
    PutBitContext pb;

    /* sequence parameters */
    int context_initialized;
    int input_picture_number;  ///< used to set pic->display_picture_number, shouldnt be used for/by anything else
    int coded_picture_number;  ///< used to set pic->coded_picture_number, shouldnt 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 addressng of left & top MBs withoutt sig11
    int b8_stride;             ///< 2*mb_width+1 used for some 8x8 block arrays to allow simple addressng
    int b4_stride;             ///< 4*mb_width+1 used for some 4x4 block arrays to allow simple addressng
    int h_edge_pos, v_edge_pos;///< horizontal / vertical position of the right/bottom edge (pixel replicateion)
    int mb_num;                ///< number of MBs of a picture 
    int linesize;              ///< line size, in bytes, may be different from width 
    int uvlinesize;            ///< line size, for chroma in bytes, may be different from width 
    Picture *picture;          ///< main picture buffer 
    
    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];
    
    /** 
     * copy of the previous picture structure.
     * note, linesize & data, might not match the previous picture (for field pictures)
     */
    Picture last_picture;       
    
    /** 
     * copy of the next picture structure.
     * note, linesize & data, might not match the next picture (for field pictures)
     */
    Picture next_picture;
        
    /** 
     * copy of the current picture structure.
     * note, linesize & data, might not match the current picture (for field pictures)
     */
    Picture current_picture;    ///< buffer to store the decompressed current picture 
    
    Picture *last_picture_ptr;     ///< pointer to the previous picture.
    Picture *next_picture_ptr;     ///< pointer to the next picture (for bidir pred) 
    Picture *current_picture_ptr;  ///< pointer to the current picture
    
    uint8_t *prev_pict_types;     ///< previous picture types in bitstream order, used for mb skip 
#define PREV_PICT_TYPES_BUFFER_SIZE 256
    int mb_skiped;                ///< 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 *allocated_edge_emu_buffer;
    uint8_t *edge_emu_buffer;     ///< points into the middle of allocated_edge_emu_buffer
    
    int qscale;                 ///< QP 
    int chroma_qscale;          ///< chroma QP 
    
    int pict_type;              ///< I_TYPE, P_TYPE, B_TYPE, ... 
    int last_pict_type;
    int last_non_b_pict_type;   ///< used for mpeg4 gmc b-frames & ratecontrol 
    
    /* motion compensation */
    int unrestricted_mv;        ///< mv can point outside of the coded picture 

    int decode;                 ///< if 0 then decoding will be skiped (for encoding b frames for example)

    DSPContext dsp;             ///< pointers for accelerated dsp fucntions 
        
    int hurry_up;     /**< when set to 1 during decoding, b frames will be skiped
                         when set to 2 idct/dequant will be skipped too */
                        
    /* macroblock layer */
    int mb_x, mb_y;
    int mb_skip_run;
    int mb_intra;

#define CANDIDATE_MB_TYPE_INTRA    0x01
#define CANDIDATE_MB_TYPE_INTER    0x02
#define CANDIDATE_MB_TYPE_INTER4V  0x04
#define CANDIDATE_MB_TYPE_SKIPED   0x08
//#define MB_TYPE_GMC      0x10

#define CANDIDATE_MB_TYPE_DIRECT   0x10
#define CANDIDATE_MB_TYPE_FORWARD  0x20
#define CANDIDATE_MB_TYPE_BACKWARD 0x40
#define CANDIDATE_MB_TYPE_BIDIR    0x80

#define CANDIDATE_MB_TYPE_INTER_I    0x100
#define CANDIDATE_MB_TYPE_FORWARD_I  0x200
#define CANDIDATE_MB_TYPE_BACKWARD_I 0x400
#define CANDIDATE_MB_TYPE_BIDIR_I    0x800

    int block_wrap[6];
    uint8_t *dest[3];
    
    int *mb_index2xy;        ///< mb_index -> mb_x + mb_y*mb_stride
    
    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 *inter_ac_vlc_length;
    uint8_t *inter_ac_vlc_last_length;
    uint8_t *luma_dc_vlc_length;

#define UNI_AC_ENC_INDEX(run,level) ((run)*128 + (level))
    
   
    int block_last_index[12];  ///< last non zero coefficient in block
    /* scantables */
    ScanTable __align8 intra_scantable;
    ScanTable intra_h_scantable;
    ScanTable intra_v_scantable;
    ScanTable inter_scantable; ///< if inter == intra then intra should be used to reduce tha cache usage
        
    
#define VP_START            1          ///< current MB is the first after a resync marker 
#define AC_ERROR            2
#define DC_ERROR            4
#define MV_ERROR            8
#define AC_END              16
#define DC_END              32
#define MV_END              64
//FIXME some prefix?
    
    
    
    ParseContext parse_context;
    
    /* mpeg4 specific */    
    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 
            
    /* lavc specific stuff, used to workaround bugs in libavcodec */
    int ffmpeg_version;
    int lavc_build;    
    

    /* decompression specific */
    GetBitContext gb;

    int broken_link;         ///< no_output_of_prior_pics_flag
    
    /* MPEG2 specific - I wish I had not to support this mess. */
    int progressive_sequence;
    int picture_structure;
/* picture type */
#define PICT_TOP_FIELD     1
#define PICT_BOTTOM_FIELD  2
#define PICT_FRAME         3
   
    int top_field_first;
    int alternate_scan;
    
    int progressive_frame;
    
    short * pblocks[12];
    
    DCTELEM (*block)[64]; ///< points to one of the following blocks 
    DCTELEM (*blocks)[6][64]; // for HQ mode we need to keep the best block
    int (*decode_mb)(struct MpegEncContext *s, DCTELEM block[6][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_intra)(struct MpegEncContext *s, // unquantizer to use (mpeg4 can use both)
                           DCTELEM *block/*align 16*/, int n, int qscale);
    void (*dct_unquantize_inter)(struct MpegEncContext *s, // unquantizer to use (mpeg4 can use both)
                           DCTELEM *block/*align 16*/, int n, int qscale);
    int (*dct_quantize)(struct MpegEncContext *s, DCTELEM *block/*align 16*/, int n, int qscale, int *overflow);
    int (*fast_dct_quantize)(struct MpegEncContext *s, DCTELEM *block/*align 16*/, int n, int qscale, int *overflow);
    
} MpegEncContext;


int DCT_common_init(MpegEncContext *s);
void MPV_decode_defaults(MpegEncContext *s);
int MPV_common_init(MpegEncContext *s);
void MPV_common_end(MpegEncContext *s);
void MPV_decode_mb(MpegEncContext *s, DCTELEM block[6][64]);
int MPV_frame_start(MpegEncContext *s, AVCodecContext *avctx);
void MPV_frame_end(MpegEncContext *s);

extern void (*draw_edges)(uint8_t *buf, int wrap, int width, int height, int w);
void ff_copy_bits(PutBitContext *pb, uint8_t *src, int length);
void ff_clean_intra_table_entries(MpegEncContext *s);
void ff_init_scantable(uint8_t *, ScanTable *st, const uint8_t *src_scantable);
void ff_draw_horiz_band(MpegEncContext *s, int y, int h);
void ff_emulated_edge_mc(uint8_t *buf, uint8_t *src, int linesize, int block_w, int block_h, 
                                    int src_x, int src_y, int w, int h);
#define END_NOT_FOUND -100
int ff_combine_frame( MpegEncContext *s, int next, uint8_t **buf, int *buf_size);

int ff_find_unused_picture(MpegEncContext *s, int shared);


#endif /* AVCODEC_MPEGVIDEO_H */