avcodec.h

#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< allow non standarized experimental things

    /**
     * qscale offset between ip and b frames.
     * if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset)
     * if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset)
     * - encoding: set by user.
     * - decoding: unused
     */
    float b_quant_offset;

    /**
     * error resilience higher values will detect more errors but may missdetect
     * some more or less valid parts as errors.
     * - encoding: unused
     * - decoding: set by user
     */
    int error_resilience;
#define FF_ER_CAREFUL         1
#define FF_ER_COMPLIANT       2
#define FF_ER_AGGRESSIVE      3
#define FF_ER_VERY_AGGRESSIVE 4

    /**
     * called at the beginning of each frame to get a buffer for it.
     * if pic.reference is set then the frame will be read later by lavc
     * avcodec_align_dimensions() should be used to find the required width and
     * height, as they normally need to be rounded up to the next multiple of 16
     * - encoding: unused
     * - decoding: set by lavc, user can override
     */
    int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);

    /**
     * called to release buffers which where allocated with get_buffer.
     * a released buffer can be reused in get_buffer()
     * pic.data[*] must be set to NULL
     * - encoding: unused
     * - decoding: set by lavc, user can override
     */
    void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);

    /**
     * if 1 the stream has a 1 frame delay during decoding.
     * - encoding: set by lavc
     * - decoding: set by lavc
     */
    int has_b_frames;

    /**
     * number of bytes per packet if constant and known or 0
     * used by some WAV based audio codecs
     */
    int block_align;

    int parse_only; /* - decoding only: if true, only parsing is done
                       (function avcodec_parse_frame()). The frame
                       data is returned. Only MPEG codecs support this now. */

    /**
     * 0-> h263 quant 1-> mpeg quant.
     * - encoding: set by user.
     * - decoding: unused
     */
    int mpeg_quant;

    /**
     * pass1 encoding statistics output buffer.
     * - encoding: set by lavc
     * - decoding: unused
     */
    char *stats_out;

    /**
     * pass2 encoding statistics input buffer.
     * concatenated stuff from stats_out of pass1 should be placed here
     * - encoding: allocated/set/freed by user
     * - decoding: unused
     */
    char *stats_in;

    /**
     * ratecontrol qmin qmax limiting method.
     * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax
     * - encoding: set by user.
     * - decoding: unused
     */
    float rc_qsquish;

    float rc_qmod_amp;
    int rc_qmod_freq;

    /**
     * ratecontrol override, see RcOverride.
     * - encoding: allocated/set/freed by user.
     * - decoding: unused
     */
    RcOverride *rc_override;
    int rc_override_count;

    /**
     * rate control equation.
     * - encoding: set by user
     * - decoding: unused
     */
    char *rc_eq;

    /**
     * maximum bitrate.
     * - encoding: set by user.
     * - decoding: unused
     */
    int rc_max_rate;

    /**
     * minimum bitrate.
     * - encoding: set by user.
     * - decoding: unused
     */
    int rc_min_rate;

    /**
     * decoder bitstream buffer size.
     * - encoding: set by user.
     * - decoding: unused
     */
    int rc_buffer_size;
    float rc_buffer_aggressivity;

    /**
     * qscale factor between p and i frames.
     * if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset)
     * if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset)
     * - encoding: set by user.
     * - decoding: unused
     */
    float i_quant_factor;

    /**
     * qscale offset between p and i frames.
     * - encoding: set by user.
     * - decoding: unused
     */
    float i_quant_offset;

    /**
     * initial complexity for pass1 ratecontrol.
     * - encoding: set by user.
     * - decoding: unused
     */
    float rc_initial_cplx;

    /**
     * dct algorithm, see FF_DCT_* below.
     * - encoding: set by user
     * - decoding: unused
     */
    int dct_algo;
#define FF_DCT_AUTO    0
#define FF_DCT_FASTINT 1
#define FF_DCT_INT     2
#define FF_DCT_MMX     3
#define FF_DCT_MLIB    4
#define FF_DCT_ALTIVEC 5
#define FF_DCT_FAAN    6

    /**
     * luminance masking (0-> disabled).
     * - encoding: set by user
     * - decoding: unused
     */
    float lumi_masking;

    /**
     * temporary complexity masking (0-> disabled).
     * - encoding: set by user
     * - decoding: unused
     */
    float temporal_cplx_masking;

    /**
     * spatial complexity masking (0-> disabled).
     * - encoding: set by user
     * - decoding: unused
     */
    float spatial_cplx_masking;

    /**
     * p block masking (0-> disabled).
     * - encoding: set by user
     * - decoding: unused
     */
    float p_masking;

    /**
     * darkness masking (0-> disabled).
     * - encoding: set by user
     * - decoding: unused
     */
    float dark_masking;


    /* for binary compatibility */
    int unused;

    /**
     * idct algorithm, see FF_IDCT_* below.
     * - encoding: set by user
     * - decoding: set by user
     */
    int idct_algo;
#define FF_IDCT_AUTO         0
#define FF_IDCT_INT          1
#define FF_IDCT_SIMPLE       2
#define FF_IDCT_SIMPLEMMX    3
#define FF_IDCT_LIBMPEG2MMX  4
#define FF_IDCT_PS2          5
#define FF_IDCT_MLIB         6
#define FF_IDCT_ARM          7
#define FF_IDCT_ALTIVEC      8
#define FF_IDCT_SH4          9
#define FF_IDCT_SIMPLEARM    10
#define FF_IDCT_H264         11
#define FF_IDCT_VP3          12
#define FF_IDCT_IPP          13
#define FF_IDCT_XVIDMMX      14
#define FF_IDCT_CAVS         15
#define FF_IDCT_SIMPLEARMV5TE 16

    /**
     * slice count.
     * - encoding: set by lavc
     * - decoding: set by user (or 0)
     */
    int slice_count;
    /**
     * slice offsets in the frame in bytes.
     * - encoding: set/allocated by lavc
     * - decoding: set/allocated by user (or NULL)
     */
    int *slice_offset;

    /**
     * error concealment flags.
     * - encoding: unused
     * - decoding: set by user
     */
    int error_concealment;
#define FF_EC_GUESS_MVS   1
#define FF_EC_DEBLOCK     2

    /**
     * dsp_mask could be add used to disable unwanted CPU features
     * CPU features (i.e. MMX, SSE. ...)
     *
     * with FORCE flag you may instead enable given CPU features
     * (Dangerous: usable in case of misdetection, improper usage however will
     * result into program crash)
     */
    unsigned dsp_mask;
#define FF_MM_FORCE    0x80000000 /* force usage of selected flags (OR) */
    /* lower 16 bits - CPU features */
#ifdef HAVE_MMX
#define FF_MM_MMX      0x0001 /* standard MMX */
#define FF_MM_3DNOW    0x0004 /* AMD 3DNOW */
#define FF_MM_MMXEXT   0x0002 /* SSE integer functions or AMD MMX ext */
#define FF_MM_SSE      0x0008 /* SSE functions */
#define FF_MM_SSE2     0x0010 /* PIV SSE2 functions */
#define FF_MM_3DNOWEXT 0x0020 /* AMD 3DNowExt */
#endif /* HAVE_MMX */
#ifdef HAVE_IWMMXT
#define FF_MM_IWMMXT   0x0100 /* XScale IWMMXT */
#endif /* HAVE_IWMMXT */

    /**
     * bits per sample/pixel from the demuxer (needed for huffyuv).
     * - encoding: set by lavc
     * - decoding: set by user
     */
     int bits_per_sample;

    /**
     * prediction method (needed for huffyuv).
     * - encoding: set by user
     * - decoding: unused
     */
     int prediction_method;
#define FF_PRED_LEFT   0
#define FF_PRED_PLANE  1
#define FF_PRED_MEDIAN 2

    /**
     * sample aspect ratio (0 if unknown).
     * numerator and denominator must be relative prime and smaller then 256 for some video standards
     * - encoding: set by user.
     * - decoding: set by lavc.
     */
    AVRational sample_aspect_ratio;

    /**
     * the picture in the bitstream.
     * - encoding: set by lavc
     * - decoding: set by lavc
     */
    AVFrame *coded_frame;

    /**
     * debug.
     * - encoding: set by user.
     * - decoding: set by user.
     */
    int debug;
#define FF_DEBUG_PICT_INFO 1
#define FF_DEBUG_RC        2
#define FF_DEBUG_BITSTREAM 4
#define FF_DEBUG_MB_TYPE   8
#define FF_DEBUG_QP        16
#define FF_DEBUG_MV        32
#define FF_DEBUG_DCT_COEFF 0x00000040
#define FF_DEBUG_SKIP      0x00000080
#define FF_DEBUG_STARTCODE 0x00000100
#define FF_DEBUG_PTS       0x00000200
#define FF_DEBUG_ER        0x00000400
#define FF_DEBUG_MMCO      0x00000800
#define FF_DEBUG_BUGS      0x00001000
#define FF_DEBUG_VIS_QP    0x00002000
#define FF_DEBUG_VIS_MB_TYPE 0x00004000

    /**
     * debug.
     * - encoding: set by user.
     * - decoding: set by user.
     */
    int debug_mv;
#define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
#define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
#define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames

    /**
     * error.
     * - encoding: set by lavc if flags&CODEC_FLAG_PSNR
     * - decoding: unused
     */
    uint64_t error[4];

    /**
     * minimum MB quantizer.
     * - encoding: unused
     * - decoding: unused
     */
    int mb_qmin;

    /**
     * maximum MB quantizer.
     * - encoding: unused
     * - decoding: unused
     */
    int mb_qmax;

    /**
     * motion estimation compare function.
     * - encoding: set by user.
     * - decoding: unused
     */
    int me_cmp;
    /**
     * subpixel motion estimation compare function.
     * - encoding: set by user.
     * - decoding: unused
     */
    int me_sub_cmp;
    /**
     * macroblock compare function (not supported yet).
     * - encoding: set by user.
     * - decoding: unused
     */
    int mb_cmp;
    /**
     * interlaced dct compare function
     * - encoding: set by user.
     * - decoding: unused
     */
    int ildct_cmp;
#define FF_CMP_SAD  0
#define FF_CMP_SSE  1
#define FF_CMP_SATD 2
#define FF_CMP_DCT  3
#define FF_CMP_PSNR 4
#define FF_CMP_BIT  5
#define FF_CMP_RD   6
#define FF_CMP_ZERO 7
#define FF_CMP_VSAD 8
#define FF_CMP_VSSE 9
#define FF_CMP_NSSE 10
#define FF_CMP_W53  11
#define FF_CMP_W97  12
#define FF_CMP_DCTMAX 13
#define FF_CMP_DCT264 14
#define FF_CMP_CHROMA 256

    /**
     * ME diamond size & shape.
     * - encoding: set by user.
     * - decoding: unused
     */
    int dia_size;

    /**
     * amount of previous MV predictors (2a+1 x 2a+1 square).
     * - encoding: set by user.
     * - decoding: unused
     */
    int last_predictor_count;

    /**
     * pre pass for motion estimation.
     * - encoding: set by user.
     * - decoding: unused
     */
    int pre_me;

    /**
     * motion estimation pre pass compare function.
     * - encoding: set by user.
     * - decoding: unused
     */
    int me_pre_cmp;

    /**
     * ME pre pass diamond size & shape.
     * - encoding: set by user.
     * - decoding: unused
     */
    int pre_dia_size;

    /**
     * subpel ME quality.
     * - encoding: set by user.
     * - decoding: unused
     */
    int me_subpel_quality;

    /**
     * callback to negotiate the pixelFormat.
     * @param fmt is the list of formats which are supported by the codec,
     * its terminated by -1 as 0 is a valid format, the formats are ordered by quality
     * the first is allways the native one
     * @return the choosen format
     * - encoding: unused
     * - decoding: set by user, if not set then the native format will always be choosen
     */
    enum PixelFormat (*get_format)(struct AVCodecContext *s, const enum PixelFormat * fmt);

    /**
     * DTG active format information (additionnal aspect ratio
     * information only used in DVB MPEG2 transport streams). 0 if
     * not set.
     *
     * - encoding: unused.
     * - decoding: set by decoder
     */
    int dtg_active_format;
#define FF_DTG_AFD_SAME         8
#define FF_DTG_AFD_4_3          9
#define FF_DTG_AFD_16_9         10
#define FF_DTG_AFD_14_9         11
#define FF_DTG_AFD_4_3_SP_14_9  13
#define FF_DTG_AFD_16_9_SP_14_9 14
#define FF_DTG_AFD_SP_4_3       15

    /**
     * Maximum motion estimation search range in subpel units.
     * if 0 then no limit
     *
     * - encoding: set by user.
     * - decoding: unused.
     */
    int me_range;

    /**
     * intra quantizer bias.
     * - encoding: set by user.
     * - decoding: unused
     */
    int intra_quant_bias;
#define FF_DEFAULT_QUANT_BIAS 999999

    /**
     * inter quantizer bias.
     * - encoding: set by user.
     * - decoding: unused
     */
    int inter_quant_bias;

    /**
     * color table ID.
     * - encoding: unused.
     * - decoding: which clrtable should be used for 8bit RGB images
     *             table have to be stored somewhere FIXME
     */
    int color_table_id;

    /**
     * internal_buffer count.
     * Don't touch, used by lavc default_get_buffer()
     */
    int internal_buffer_count;

    /**
     * internal_buffers.
     * Don't touch, used by lavc default_get_buffer()
     */
    void *internal_buffer;

#define FF_LAMBDA_SHIFT 7
#define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
#define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
#define FF_LAMBDA_MAX (256*128-1)

#define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
    /**
     * global quality for codecs which cannot change it per frame.
     * this should be proportional to MPEG1/2/4 qscale.
     * - encoding: set by user.
     * - decoding: unused
     */
    int global_quality;

#define FF_CODER_TYPE_VLC   0
#define FF_CODER_TYPE_AC    1
    /**
     * coder type
     * - encoding: set by user.
     * - decoding: unused
     */
    int coder_type;

    /**
     * context model
     * - encoding: set by user.
     * - decoding: unused
     */
    int context_model;
#if 0
    /**
     *
     * - encoding: unused
     * - decoding: set by user.
     */
    uint8_t * (*realloc)(struct AVCodecContext *s, uint8_t *buf, int buf_size);
#endif

    /**
     * slice flags
     * - encoding: unused
     * - decoding: set by user.
     */
    int slice_flags;
#define SLICE_FLAG_CODED_ORDER    0x0001 ///< draw_horiz_band() is called in coded order instead of display
#define SLICE_FLAG_ALLOW_FIELD    0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
#define SLICE_FLAG_ALLOW_PLANE    0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)

    /**
     * XVideo Motion Acceleration
     * - encoding: forbidden
     * - decoding: set by decoder
     */
    int xvmc_acceleration;

    /**
     * macroblock decision mode
     * - encoding: set by user.
     * - decoding: unused
     */
    int mb_decision;
#define FF_MB_DECISION_SIMPLE 0        ///< uses mb_cmp
#define FF_MB_DECISION_BITS   1        ///< chooses the one which needs the fewest bits
#define FF_MB_DECISION_RD     2        ///< rate distoration

    /**
     * custom intra quantization matrix
     * - encoding: set by user, can be NULL
     * - decoding: set by lavc
     */
    uint16_t *intra_matrix;

    /**
     * custom inter quantization matrix
     * - encoding: set by user, can be NULL
     * - decoding: set by lavc
     */
    uint16_t *inter_matrix;

    /**
     * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
     * this is used to workaround some encoder bugs
     * - encoding: unused
     * - decoding: set by user, will be converted to upper case by lavc during init
     */
    unsigned int stream_codec_tag;

    /**
     * scene change detection threshold.
     * 0 is default, larger means fewer detected scene changes
     * - encoding: set by user.
     * - decoding: unused
     */
    int scenechange_threshold;

    /**
     * minimum lagrange multipler
     * - encoding: set by user.
     * - decoding: unused
     */
    int lmin;

    /**
     * maximum lagrange multipler
     * - encoding: set by user.
     * - decoding: unused
     */
    int lmax;

    /**
     * Palette control structure
     * - encoding: ??? (no palette-enabled encoder yet)
     * - decoding: set by user.
     */
    struct AVPaletteControl *palctrl;

    /**
     * noise reduction strength
     * - encoding: set by user.
     * - decoding: unused
     */
    int noise_reduction;

    /**
     * called at the beginning of a frame to get cr buffer for it.
     * buffer type (size, hints) must be the same. lavc won't check it.
     * lavc will pass previous buffer in pic, function should return
     * same buffer or new buffer with old frame "painted" into it.
     * if pic.data[0] == NULL must behave like get_buffer().
     * - encoding: unused
     * - decoding: set by lavc, user can override
     */
    int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);

    /**
     * number of bits which should be loaded into the rc buffer before decoding starts
     * - encoding: set by user.
     * - decoding: unused
     */
    int rc_initial_buffer_occupancy;

    /**
     *
     * - encoding: set by user.
     * - decoding: unused
     */
    int inter_threshold;

    /**
     * CODEC_FLAG2_*.
     * - encoding: set by user.
     * - decoding: set by user.
     */
    int flags2;

    /**
     * simulates errors in the bitstream to test error concealment.
     * - encoding: set by user.
     * - decoding: unused.
     */
    int error_rate;

    /**
     * MP3 antialias algorithm, see FF_AA_* below.
     * - encoding: unused
     * - decoding: set by user
     */
    int antialias_algo;
#define FF_AA_AUTO    0
#define FF_AA_FASTINT 1 //not implemented yet
#define FF_AA_INT     2
#define FF_AA_FLOAT   3
    /**
     * Quantizer noise shaping.
     * - encoding: set by user
     * - decoding: unused
     */
    int quantizer_noise_shaping;

    /**
     * Thread count.
     * is used to decide how many independant tasks should be passed to execute()
     * - encoding: set by user
     * - decoding: set by user
     */
    int thread_count;

    /**
     * the codec may call this to execute several independant things. it will return only after
     * finishing all tasks, the user may replace this with some multithreaded implementation, the
     * default implementation will execute the parts serially
     * @param count the number of things to execute
     * - encoding: set by lavc, user can override
     * - decoding: set by lavc, user can override
     */
    int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void **arg2, int *ret, int count);

    /**
     * Thread opaque.
     * can be used by execute() to store some per AVCodecContext stuff.
     * - encoding: set by execute()
     * - decoding: set by execute()
     */
    void *thread_opaque;

    /**
     * Motion estimation threshold. under which no motion estimation is
     * performed, but instead the user specified motion vectors are used
     *
     * - encoding: set by user
     * - decoding: unused
     */
     int me_threshold;

    /**
     * Macroblock threshold. under which the user specified macroblock types will be used
     * - encoding: set by user
     * - decoding: unused
     */
     int mb_threshold;

    /**
     * precision of the intra dc coefficient - 8.
     * - encoding: set by user
     * - decoding: unused
     */
     int intra_dc_precision;

    /**
     * noise vs. sse weight for the nsse comparsion function.
     * - encoding: set by user
     * - decoding: unused
     */
     int nsse_weight;

    /**
     * number of macroblock rows at the top which are skipped.
     * - encoding: unused
     * - decoding: set by user
     */
     int skip_top;

    /**
     * number of macroblock rows at the bottom which are skipped.
     * - encoding: unused
     * - decoding: set by user
     */
     int skip_bottom;

    /**
     * profile
     * - encoding: set by user
     * - decoding: set by lavc
     */
     int profile;
#define FF_PROFILE_UNKNOWN -99

    /**
     * level
     * - encoding: set by user
     * - decoding: set by lavc
     */
     int level;
#define FF_LEVEL_UNKNOWN -99

    /**
     * low resolution decoding. 1-> 1/2 size, 2->1/4 size
     * - encoding: unused
     * - decoding: set by user
     */
     int lowres;

    /**
     * bitsream width / height. may be different from width/height if lowres
     * or other things are used
     * - encoding: unused
     * - decoding: set by user before init if known, codec should override / dynamically change if needed
     */
    int coded_width, coded_height;

    /**
     * frame skip threshold
     * - encoding: set by user
     * - decoding: unused
     */
    int frame_skip_threshold;

    /**
     * frame skip factor
     * - encoding: set by user
     * - decoding: unused
     */
    int frame_skip_factor;

    /**
     * frame skip exponent
     * - encoding: set by user
     * - decoding: unused
     */
    int frame_skip_exp;

    /**
     * frame skip comparission function
     * - encoding: set by user.
     * - decoding: unused
     */
    int frame_skip_cmp;

    /**
     * border processing masking. raises the quantizer for mbs on the borders
     * of the picture.
     * - encoding: set by user
     * - decoding: unused
     */
    float border_masking;

    /**
     * minimum MB lagrange multipler.
     * - encoding: set by user.
     * - decoding: unused
     */
    int mb_lmin;

    /**
     * maximum MB lagrange multipler.
     * - encoding: set by user.
     * - decoding: unused
     */
    int mb_lmax;

    /**
     *
     * - encoding: set by user.
     * - decoding: unused
     */
    int me_penalty_compensation;

    /**
     *
     * - encoding: unused
     * - decoding: set by user.
     */
    enum AVDiscard skip_loop_filter;

    /**
     *
     * - encoding: unused
     * - decoding: set by user.
     */
    enum AVDiscard skip_idct;

    /**
     *
     * - encoding: unused
     * - decoding: set by user.
     */
    enum AVDiscard skip_frame;

    /**
     *
     * - encoding: set by user.
     * - decoding: unused
     */
    int bidir_refine;

    /**
     *
     * - encoding: set by user.
     * - decoding: unused
     */
    int brd_scale;

    /**
     * constant rate factor - quality-based VBR - values ~correspond to qps
     * - encoding: set by user.
     * - decoding: unused
     */
    int crf;

    /**
     * constant quantization parameter rate control method
     * - encoding: set by user.
     * - decoding: unused
     */
    int cqp;

    /**
     * minimum gop size
     * - encoding: set by user.
     * - decoding: unused
     */
    int keyint_min;

    /**
     * number of reference frames
     * - encoding: set by user.
     * - decoding: unused
     */
    int refs;

    /**
     * chroma qp offset from luma
     * - encoding: set by user.
     * - decoding: unused
     */
    int chromaoffset;

    /**
     * influences how often b-frames are used
     * - encoding: set by user.
     * - decoding: unused
     */
    int bframebias;

    /**
     * trellis RD quantization
     * - encoding: set by user.
     * - decoding: unused
     */
    int trellis;

    /**
     * reduce fluctuations in qp (before curve compression)
     * - encoding: set by user.
     * - decoding: unused
     */
    float complexityblur;

    /**
     * in-loop deblocking filter alphac0 parameter
     * alpha is in the range -6...6
     * - encoding: set by user.
     * - decoding: unused
     */
    int deblockalpha;

    /**
     * in-loop deblocking filter beta parameter
     * beta is in the range -6...6
     * - encoding: set by user.
     * - decoding: unused
     */
    int deblockbeta;

    /**
     * macroblock subpartition sizes to consider - p8x8, p4x4, b8x8, i8x8, i4x4
     * - encoding: set by user.
     * - decoding: unused
     */
    int partitions;
#define X264_PART_I4X4 0x001  /* Analyse i4x4 */
#define X264_PART_I8X8 0x002  /* Analyse i8x8 (requires 8x8 transform) */
#define X264_PART_P8X8 0x010  /* Analyse p16x8, p8x16 and p8x8 */
#define X264_PART_P4X4 0x020  /* Analyse p8x4, p4x8, p4x4 */
#define X264_PART_B8X8 0x100  /* Analyse b16x8, b8x16 and b8x8 */

    /**
     * direct mv prediction mode - 0 (none), 1 (spatial), 2 (temporal)
     * - encoding: set by user.
     * - decoding: unused
     */
    int directpred;

    /**
     * audio cutoff bandwidth (0 means "automatic") . Currently used only by FAAC
     * - encoding: set by user.
     * - decoding: unused
     */
    int cutoff;

    /**
     * multiplied by qscale for each frame and added to scene_change_score
     * - encoding: set by user.
     * - decoding: unused
     */
    int scenechange_factor;

    /**
     *
     * note: value depends upon the compare functin used for fullpel ME
     * - encoding: set by user.
     * - decoding: unused
     */
    int mv0_threshold;

    /**