encoder.c

/*****************************************************************************
 * x264: h264 encoder
 *****************************************************************************
 * Copyright (C) 2003 Laurent Aimar
 * $Id: encoder.c,v 1.1 2004/06/03 19:27:08 fenrir Exp $
 *
 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

#include <math.h>

#include "common/common.h"
#include "common/cpu.h"

#include "set.h"
#include "analyse.h"
#include "ratecontrol.h"
#include "macroblock.h"

#if VISUALIZE
#include "common/visualize.h"
#endif

//#define DEBUG_MB_TYPE
//#define DEBUG_DUMP_FRAME
//#define DEBUG_BENCHMARK

#ifdef DEBUG_BENCHMARK
static int64_t i_mtime_encode_frame = 0;
static int64_t i_mtime_analyse = 0;
static int64_t i_mtime_encode = 0;
static int64_t i_mtime_write = 0;
static int64_t i_mtime_filter = 0;
#define TIMER_START( d ) \
    { \
        int64_t d##start = x264_mdate();

#define TIMER_STOP( d ) \
        d += x264_mdate() - d##start;\
    }
#else
#define TIMER_START( d )
#define TIMER_STOP( d )
#endif

#define NALU_OVERHEAD 5 // startcode + NAL type costs 5 bytes per frame

static void x264_encoder_frame_end( x264_t *h, x264_t *thread_current,
                                    x264_nal_t **pp_nal, int *pi_nal,
                                    x264_picture_t *pic_out );

/****************************************************************************
 *
 ******************************* x264 libs **********************************
 *
 ****************************************************************************/
static float x264_psnr( int64_t i_sqe, int64_t i_size )
{
    double f_mse = (double)i_sqe / ((double)65025.0 * (double)i_size);
    if( f_mse <= 0.0000000001 ) /* Max 100dB */
        return 100;

    return (float)(-10.0 * log( f_mse ) / log( 10.0 ));
}

#ifdef DEBUG_DUMP_FRAME
static void x264_frame_dump( x264_t *h, x264_frame_t *fr, char *name )
{
    FILE *f = fopen( name, "r+b" );
    int i, y;
    if( !f )
        return;

    /* Write the frame in display order */
    fseek( f, fr->i_frame * h->param.i_height * h->param.i_width * 3 / 2, SEEK_SET );

    for( i = 0; i < fr->i_plane; i++ )
    {
        for( y = 0; y < h->param.i_height / ( i == 0 ? 1 : 2 ); y++ )
        {
            fwrite( &fr->plane[i][y*fr->i_stride[i]], 1, h->param.i_width / ( i == 0 ? 1 : 2 ), f );
        }
    }
    fclose( f );
}
#endif


/* Fill "default" values */
static void x264_slice_header_init( x264_t *h, x264_slice_header_t *sh,
                                    x264_sps_t *sps, x264_pps_t *pps,
                                    int i_idr_pic_id, int i_frame, int i_qp )
{
    x264_param_t *param = &h->param;
    int i;

    /* First we fill all field */
    sh->sps = sps;
    sh->pps = pps;

    sh->i_first_mb  = 0;
    sh->i_last_mb   = h->sps->i_mb_width * h->sps->i_mb_height;
    sh->i_pps_id    = pps->i_id;

    sh->i_frame_num = i_frame;

    sh->b_mbaff = h->param.b_interlaced;
    sh->b_field_pic = 0;    /* no field support for now */
    sh->b_bottom_field = 0; /* not yet used */

    sh->i_idr_pic_id = i_idr_pic_id;

    /* poc stuff, fixed later */
    sh->i_poc_lsb = 0;
    sh->i_delta_poc_bottom = 0;
    sh->i_delta_poc[0] = 0;
    sh->i_delta_poc[1] = 0;

    sh->i_redundant_pic_cnt = 0;

    if( !h->mb.b_direct_auto_read )
    {
        if( h->mb.b_direct_auto_write )
            sh->b_direct_spatial_mv_pred = ( h->stat.i_direct_score[1] > h->stat.i_direct_score[0] );
        else
            sh->b_direct_spatial_mv_pred = ( param->analyse.i_direct_mv_pred == X264_DIRECT_PRED_SPATIAL );
    }
    /* else b_direct_spatial_mv_pred was read from the 2pass statsfile */

    sh->b_num_ref_idx_override = 0;
    sh->i_num_ref_idx_l0_active = 1;
    sh->i_num_ref_idx_l1_active = 1;

    sh->b_ref_pic_list_reordering_l0 = h->b_ref_reorder[0];
    sh->b_ref_pic_list_reordering_l1 = h->b_ref_reorder[1];

    /* If the ref list isn't in the default order, construct reordering header */
    /* List1 reordering isn't needed yet */
    if( sh->b_ref_pic_list_reordering_l0 )
    {
        int pred_frame_num = i_frame;
        for( i = 0; i < h->i_ref0; i++ )
        {
            int diff = h->fref0[i]->i_frame_num - pred_frame_num;
            if( diff == 0 )
                x264_log( h, X264_LOG_ERROR, "diff frame num == 0\n" );
            sh->ref_pic_list_order[0][i].idc = ( diff > 0 );
            sh->ref_pic_list_order[0][i].arg = abs( diff ) - 1;
            pred_frame_num = h->fref0[i]->i_frame_num;
        }
    }

    sh->i_cabac_init_idc = param->i_cabac_init_idc;

    sh->i_qp = i_qp;
    sh->i_qp_delta = i_qp - pps->i_pic_init_qp;
    sh->b_sp_for_swidth = 0;
    sh->i_qs_delta = 0;

    /* If effective qp <= 15, deblocking would have no effect anyway */
    if( param->b_deblocking_filter
        && ( h->mb.b_variable_qp
        || 15 < i_qp + 2 * X264_MAX(param->i_deblocking_filter_alphac0, param->i_deblocking_filter_beta) ) )
    {
        sh->i_disable_deblocking_filter_idc = 0;
    }
    else
    {
        sh->i_disable_deblocking_filter_idc = 1;
    }
    sh->i_alpha_c0_offset = param->i_deblocking_filter_alphac0 << 1;
    sh->i_beta_offset = param->i_deblocking_filter_beta << 1;
}

static void x264_slice_header_write( bs_t *s, x264_slice_header_t *sh, int i_nal_ref_idc )
{
    int i;

    if( sh->b_mbaff )
    {
        assert( sh->i_first_mb % (2*sh->sps->i_mb_width) == 0 );
        bs_write_ue( s, sh->i_first_mb >> 1 );
    }
    else
        bs_write_ue( s, sh->i_first_mb );

    bs_write_ue( s, sh->i_type + 5 );   /* same type things */
    bs_write_ue( s, sh->i_pps_id );
    bs_write( s, sh->sps->i_log2_max_frame_num, sh->i_frame_num );

    if( !sh->sps->b_frame_mbs_only )
    {
        bs_write1( s, sh->b_field_pic );
        if ( sh->b_field_pic )
            bs_write1( s, sh->b_bottom_field );
    }

    if( sh->i_idr_pic_id >= 0 ) /* NAL IDR */
    {
        bs_write_ue( s, sh->i_idr_pic_id );
    }

    if( sh->sps->i_poc_type == 0 )
    {
        bs_write( s, sh->sps->i_log2_max_poc_lsb, sh->i_poc_lsb );
        if( sh->pps->b_pic_order && !sh->b_field_pic )
        {
            bs_write_se( s, sh->i_delta_poc_bottom );
        }
    }
    else if( sh->sps->i_poc_type == 1 && !sh->sps->b_delta_pic_order_always_zero )
    {
        bs_write_se( s, sh->i_delta_poc[0] );
        if( sh->pps->b_pic_order && !sh->b_field_pic )
        {
            bs_write_se( s, sh->i_delta_poc[1] );
        }
    }

    if( sh->pps->b_redundant_pic_cnt )
    {
        bs_write_ue( s, sh->i_redundant_pic_cnt );
    }

    if( sh->i_type == SLICE_TYPE_B )
    {
        bs_write1( s, sh->b_direct_spatial_mv_pred );
    }
    if( sh->i_type == SLICE_TYPE_P || sh->i_type == SLICE_TYPE_SP || sh->i_type == SLICE_TYPE_B )
    {
        bs_write1( s, sh->b_num_ref_idx_override );
        if( sh->b_num_ref_idx_override )
        {
            bs_write_ue( s, sh->i_num_ref_idx_l0_active - 1 );
            if( sh->i_type == SLICE_TYPE_B )
            {
                bs_write_ue( s, sh->i_num_ref_idx_l1_active - 1 );
            }
        }
    }

    /* ref pic list reordering */
    if( sh->i_type != SLICE_TYPE_I )
    {
        bs_write1( s, sh->b_ref_pic_list_reordering_l0 );
        if( sh->b_ref_pic_list_reordering_l0 )
        {
            for( i = 0; i < sh->i_num_ref_idx_l0_active; i++ )
            {
                bs_write_ue( s, sh->ref_pic_list_order[0][i].idc );
                bs_write_ue( s, sh->ref_pic_list_order[0][i].arg );
                        
            }
            bs_write_ue( s, 3 );
        }
    }
    if( sh->i_type == SLICE_TYPE_B )
    {
        bs_write1( s, sh->b_ref_pic_list_reordering_l1 );
        if( sh->b_ref_pic_list_reordering_l1 )
        {
            for( i = 0; i < sh->i_num_ref_idx_l1_active; i++ )
            {
                bs_write_ue( s, sh->ref_pic_list_order[1][i].idc );
                bs_write_ue( s, sh->ref_pic_list_order[1][i].arg );
            }
            bs_write_ue( s, 3 );
        }
    }

    if( ( sh->pps->b_weighted_pred && ( sh->i_type == SLICE_TYPE_P || sh->i_type == SLICE_TYPE_SP ) ) ||
        ( sh->pps->b_weighted_bipred == 1 && sh->i_type == SLICE_TYPE_B ) )
    {
        /* FIXME */
    }

    if( i_nal_ref_idc != 0 )
    {
        if( sh->i_idr_pic_id >= 0 )
        {
            bs_write1( s, 0 );  /* no output of prior pics flag */
            bs_write1( s, 0 );  /* long term reference flag */
        }
        else
        {
            bs_write1( s, 0 );  /* adaptive_ref_pic_marking_mode_flag */
        }
    }

    if( sh->pps->b_cabac && sh->i_type != SLICE_TYPE_I )
    {
        bs_write_ue( s, sh->i_cabac_init_idc );
    }
    bs_write_se( s, sh->i_qp_delta );      /* slice qp delta */

    if( sh->pps->b_deblocking_filter_control )
    {
        bs_write_ue( s, sh->i_disable_deblocking_filter_idc );
        if( sh->i_disable_deblocking_filter_idc != 1 )
        {
            bs_write_se( s, sh->i_alpha_c0_offset >> 1 );
            bs_write_se( s, sh->i_beta_offset >> 1 );
        }
    }
}

/****************************************************************************
 *
 ****************************************************************************
 ****************************** External API*********************************
 ****************************************************************************
 *
 ****************************************************************************/

static int x264_validate_parameters( x264_t *h )
{
    if( h->param.i_width <= 0 || h->param.i_height <= 0 )
    {
        x264_log( h, X264_LOG_ERROR, "invalid width x height (%dx%d)\n",
                  h->param.i_width, h->param.i_height );
        return -1;
    }

    if( h->param.i_width % 2 || h->param.i_height % 2 )
    {
        x264_log( h, X264_LOG_ERROR, "width or height not divisible by 2 (%dx%d)\n",
                  h->param.i_width, h->param.i_height );
        return -1;
    }
    if( h->param.i_csp != X264_CSP_I420 )
    {
        x264_log( h, X264_LOG_ERROR, "invalid CSP (only I420 supported)\n" );
        return -1;
    }

    if( h->param.i_threads == 0 )
        h->param.i_threads = x264_cpu_num_processors() * 3/2;
    h->param.i_threads = x264_clip3( h->param.i_threads, 1, X264_THREAD_MAX );
    if( h->param.i_threads > 1 )
    {
#ifndef HAVE_PTHREAD
        x264_log( h, X264_LOG_WARNING, "not compiled with pthread support!\n");
        h->param.i_threads = 1;
#else
        if( h->param.i_scenecut_threshold >= 0 )
            h->param.b_pre_scenecut = 1;
#endif
    }

    if( h->param.b_interlaced )
    {
        if( h->param.analyse.i_me_method == X264_ME_ESA )
        {
            x264_log( h, X264_LOG_WARNING, "interlace + me=esa is not implemented\n" );
            h->param.analyse.i_me_method = X264_ME_UMH;
        }
        if( h->param.analyse.i_direct_mv_pred > X264_DIRECT_PRED_SPATIAL )
        {
            x264_log( h, X264_LOG_WARNING, "interlace + direct=temporal is not implemented\n" );
            h->param.analyse.i_direct_mv_pred = X264_DIRECT_PRED_SPATIAL;
        }
    }

    if( h->param.rc.i_rc_method < 0 || h->param.rc.i_rc_method > 2 )
    {
        x264_log( h, X264_LOG_ERROR, "no ratecontrol method specified\n" );
        return -1;
    }
    h->param.rc.f_rf_constant = x264_clip3f( h->param.rc.f_rf_constant, 0, 51 );
    h->param.rc.i_qp_constant = x264_clip3( h->param.rc.i_qp_constant, 0, 51 );
    if( h->param.rc.i_rc_method == X264_RC_CRF )
        h->param.rc.i_qp_constant = h->param.rc.f_rf_constant;
    if( (h->param.rc.i_rc_method == X264_RC_CQP || h->param.rc.i_rc_method == X264_RC_CRF)
        && h->param.rc.i_qp_constant == 0 )
    {
        h->mb.b_lossless = 1;
        h->param.i_cqm_preset = X264_CQM_FLAT;
        h->param.psz_cqm_file = NULL;
        h->param.rc.i_rc_method = X264_RC_CQP;
        h->param.rc.f_ip_factor = 1;
        h->param.rc.f_pb_factor = 1;
        h->param.analyse.b_transform_8x8 = 0;
        h->param.analyse.b_psnr = 0;
        h->param.analyse.b_ssim = 0;
        h->param.analyse.i_chroma_qp_offset = 0;
        h->param.analyse.i_trellis = 0;
        h->param.analyse.b_fast_pskip = 0;
        h->param.analyse.i_noise_reduction = 0;
        h->param.analyse.i_subpel_refine = x264_clip3( h->param.analyse.i_subpel_refine, 1, 6 );
    }
    if( h->param.rc.i_rc_method == X264_RC_CQP )
    {
        float qp_p = h->param.rc.i_qp_constant;
        float qp_i = qp_p - 6*log(h->param.rc.f_ip_factor)/log(2);
        float qp_b = qp_p + 6*log(h->param.rc.f_pb_factor)/log(2);
        h->param.rc.i_qp_min = x264_clip3( (int)(X264_MIN3( qp_p, qp_i, qp_b )), 0, 51 );
        h->param.rc.i_qp_max = x264_clip3( (int)(X264_MAX3( qp_p, qp_i, qp_b ) + .999), 0, 51 );
    }

    if( ( h->param.i_width % 16 || h->param.i_height % 16 )
        && h->param.i_height != 1080 && !h->mb.b_lossless )
    {
        // There's nothing special about 1080 in that the warning still applies to it,
        // but chances are the user can't help it if his content is already 1080p,
        // so there's no point in warning in that case.
        x264_log( h, X264_LOG_WARNING, 
                  "width or height not divisible by 16 (%dx%d), compression will suffer.\n",
                  h->param.i_width, h->param.i_height );
    }

    h->param.i_frame_reference = x264_clip3( h->param.i_frame_reference, 1, 16 );
    if( h->param.i_keyint_max <= 0 )
        h->param.i_keyint_max = 1;
    h->param.i_keyint_min = x264_clip3( h->param.i_keyint_min, 1, h->param.i_keyint_max/2+1 );

    h->param.i_bframe = x264_clip3( h->param.i_bframe, 0, X264_BFRAME_MAX );
    h->param.i_bframe_bias = x264_clip3( h->param.i_bframe_bias, -90, 100 );
    h->param.b_bframe_pyramid = h->param.b_bframe_pyramid && h->param.i_bframe > 1;
    h->param.b_bframe_adaptive = h->param.b_bframe_adaptive && h->param.i_bframe > 0;
    h->param.analyse.b_weighted_bipred = h->param.analyse.b_weighted_bipred && h->param.i_bframe > 0;
    h->mb.b_direct_auto_write = h->param.analyse.i_direct_mv_pred == X264_DIRECT_PRED_AUTO
                                && h->param.i_bframe
                                && ( h->param.rc.b_stat_write || !h->param.rc.b_stat_read );
    if( h->param.i_scenecut_threshold < 0 )
        h->param.b_pre_scenecut = 0;

    h->param.i_deblocking_filter_alphac0 = x264_clip3( h->param.i_deblocking_filter_alphac0, -6, 6 );
    h->param.i_deblocking_filter_beta    = x264_clip3( h->param.i_deblocking_filter_beta, -6, 6 );
    h->param.analyse.i_luma_deadzone[0] = x264_clip3( h->param.analyse.i_luma_deadzone[0], 0, 32 );
    h->param.analyse.i_luma_deadzone[1] = x264_clip3( h->param.analyse.i_luma_deadzone[1], 0, 32 );

    h->param.i_cabac_init_idc = x264_clip3( h->param.i_cabac_init_idc, 0, 2 );

    if( h->param.i_cqm_preset < X264_CQM_FLAT || h->param.i_cqm_preset > X264_CQM_CUSTOM )
        h->param.i_cqm_preset = X264_CQM_FLAT;

    if( h->param.analyse.i_me_method < X264_ME_DIA ||
        h->param.analyse.i_me_method > X264_ME_ESA )
        h->param.analyse.i_me_method = X264_ME_HEX;
    if( h->param.analyse.i_me_range < 4 )
        h->param.analyse.i_me_range = 4;
    if( h->param.analyse.i_me_range > 16 && h->param.analyse.i_me_method <= X264_ME_HEX )
        h->param.analyse.i_me_range = 16;
    h->param.analyse.i_subpel_refine = x264_clip3( h->param.analyse.i_subpel_refine, 1, 7 );
    h->param.analyse.b_bframe_rdo = h->param.analyse.b_bframe_rdo && h->param.analyse.i_subpel_refine >= 6;
    h->param.analyse.b_mixed_references = h->param.analyse.b_mixed_references && h->param.i_frame_reference > 1;
    h->param.analyse.inter &= X264_ANALYSE_PSUB16x16|X264_ANALYSE_PSUB8x8|X264_ANALYSE_BSUB16x16|
                              X264_ANALYSE_I4x4|X264_ANALYSE_I8x8;
    h->param.analyse.intra &= X264_ANALYSE_I4x4|X264_ANALYSE_I8x8;
    if( !(h->param.analyse.inter & X264_ANALYSE_PSUB16x16) )
        h->param.analyse.inter &= ~X264_ANALYSE_PSUB8x8;
    if( !h->param.analyse.b_transform_8x8 )
    {
        h->param.analyse.inter &= ~X264_ANALYSE_I8x8;
        h->param.analyse.intra &= ~X264_ANALYSE_I8x8;
    }
    h->param.analyse.i_chroma_qp_offset = x264_clip3(h->param.analyse.i_chroma_qp_offset, -12, 12);
    if( !h->param.b_cabac )
        h->param.analyse.i_trellis = 0;
    h->param.analyse.i_trellis = x264_clip3( h->param.analyse.i_trellis, 0, 2 );
    h->param.analyse.i_noise_reduction = x264_clip3( h->param.analyse.i_noise_reduction, 0, 1<<16 );

    {
        const x264_level_t *l = x264_levels;
        while( l->level_idc != 0 && l->level_idc != h->param.i_level_idc )
            l++;
        if( l->level_idc == 0 )
        {
            x264_log( h, X264_LOG_ERROR, "invalid level_idc: %d\n", h->param.i_level_idc );
            return -1;
        }
        if( h->param.analyse.i_mv_range <= 0 )
            h->param.analyse.i_mv_range = l->mv_range;
        else
            h->param.analyse.i_mv_range = x264_clip3(h->param.analyse.i_mv_range, 32, 512);
        if( h->param.analyse.i_direct_8x8_inference < 0 )
            h->param.analyse.i_direct_8x8_inference = l->direct8x8;
    }

    if( h->param.i_threads > 1 )
    {
        int r = h->param.analyse.i_mv_range_thread;
        int r2;
        if( r <= 0 )
        {
            // half of the available space is reserved and divided evenly among the threads,
            // the rest is allocated to whichever thread is far enough ahead to use it.
            // reserving more space increases quality for some videos, but costs more time
            // in thread synchronization.
            int max_range = (h->param.i_height + X264_THREAD_HEIGHT) / h->param.i_threads - X264_THREAD_HEIGHT;
            r = max_range / 2;
        }
        r = X264_MAX( r, h->param.analyse.i_me_range );
        r = X264_MIN( r, h->param.analyse.i_mv_range );
        // round up to use the whole mb row
        r2 = (r & ~15) + ((-X264_THREAD_HEIGHT) & 15);
        if( r2 < r )
            r2 += 16;
        x264_log( h, X264_LOG_DEBUG, "using mv_range_thread = %d\n", r2 );
        h->param.analyse.i_mv_range_thread = r2;
    }

    if( h->param.rc.f_qblur < 0 )
        h->param.rc.f_qblur = 0;
    if( h->param.rc.f_complexity_blur < 0 )
        h->param.rc.f_complexity_blur = 0;

    h->param.i_sps_id &= 31;

    if( h->param.i_log_level < X264_LOG_INFO )
    {
        h->param.analyse.b_psnr = 0;
        h->param.analyse.b_ssim = 0;
    }

    /* ensure the booleans are 0 or 1 so they can be used in math */
#define BOOLIFY(x) h->param.x = !!h->param.x
    BOOLIFY( b_cabac );
    BOOLIFY( b_deblocking_filter );
    BOOLIFY( b_interlaced );
    BOOLIFY( analyse.b_transform_8x8 );
    BOOLIFY( analyse.i_direct_8x8_inference );
    BOOLIFY( analyse.b_bidir_me );
    BOOLIFY( analyse.b_chroma_me );
    BOOLIFY( analyse.b_fast_pskip );
    BOOLIFY( rc.b_stat_write );
    BOOLIFY( rc.b_stat_read );
#undef BOOLIFY

    return 0;
}

static void mbcmp_init( x264_t *h )
{
    memcpy( h->pixf.mbcmp,
            ( h->mb.b_lossless || h->param.analyse.i_subpel_refine <= 1 ) ? h->pixf.sad : h->pixf.satd,
            sizeof(h->pixf.mbcmp) );
}

/****************************************************************************
 * x264_encoder_open:
 ****************************************************************************/
x264_t *x264_encoder_open   ( x264_param_t *param )
{
    x264_t *h = x264_malloc( sizeof( x264_t ) );
    int i;

    memset( h, 0, sizeof( x264_t ) );

    /* Create a copy of param */
    memcpy( &h->param, param, sizeof( x264_param_t ) );

    if( x264_validate_parameters( h ) < 0 )
    {
        x264_free( h );
        return NULL;
    }

    if( h->param.psz_cqm_file )
        if( x264_cqm_parse_file( h, h->param.psz_cqm_file ) < 0 )
        {
            x264_free( h );
            return NULL;
        }

    if( h->param.rc.psz_stat_out )
        h->param.rc.psz_stat_out = strdup( h->param.rc.psz_stat_out );
    if( h->param.rc.psz_stat_in )
        h->param.rc.psz_stat_in = strdup( h->param.rc.psz_stat_in );
    if( h->param.rc.psz_rc_eq )
        h->param.rc.psz_rc_eq = strdup( h->param.rc.psz_rc_eq );

    /* VUI */
    if( h->param.vui.i_sar_width > 0 && h->param.vui.i_sar_height > 0 )
    {
        int i_w = param->vui.i_sar_width;
        int i_h = param->vui.i_sar_height;

        x264_reduce_fraction( &i_w, &i_h );

        while( i_w > 65535 || i_h > 65535 )
        {
            i_w /= 2;
            i_h /= 2;
        }

        h->param.vui.i_sar_width = 0;
        h->param.vui.i_sar_height = 0;
        if( i_w == 0 || i_h == 0 )
        {
            x264_log( h, X264_LOG_WARNING, "cannot create valid sample aspect ratio\n" );
        }
        else
        {
            x264_log( h, X264_LOG_INFO, "using SAR=%d/%d\n", i_w, i_h );
            h->param.vui.i_sar_width = i_w;
            h->param.vui.i_sar_height = i_h;
        }
    }

    x264_reduce_fraction( &h->param.i_fps_num, &h->param.i_fps_den );

    /* Init x264_t */
    h->i_frame = 0;
    h->i_frame_num = 0;
    h->i_idr_pic_id = 0;

    h->sps = &h->sps_array[0];
    x264_sps_init( h->sps, h->param.i_sps_id, &h->param );

    h->pps = &h->pps_array[0];
    x264_pps_init( h->pps, h->param.i_sps_id, &h->param, h->sps);

    x264_validate_levels( h );

    if( x264_cqm_init( h ) < 0 )
    {
        x264_free( h );
        return NULL;
    }
    
    h->mb.i_mb_count = h->sps->i_mb_width * h->sps->i_mb_height;

    /* Init frames. */
    h->frames.i_delay = h->param.i_bframe + h->param.i_threads - 1;
    h->frames.i_max_ref0 = h->param.i_frame_reference;
    h->frames.i_max_ref1 = h->sps->vui.i_num_reorder_frames;
    h->frames.i_max_dpb  = h->sps->vui.i_max_dec_frame_buffering;
    h->frames.b_have_lowres = !h->param.rc.b_stat_read
        && ( h->param.rc.i_rc_method == X264_RC_ABR
          || h->param.rc.i_rc_method == X264_RC_CRF
          || h->param.b_bframe_adaptive
          || h->param.b_pre_scenecut );

    h->frames.i_last_idr = - h->param.i_keyint_max;
    h->frames.i_input    = 0;
    h->frames.last_nonb  = NULL;

    h->i_ref0 = 0;
    h->i_ref1 = 0;

    x264_rdo_init( );

    /* init CPU functions */
    x264_predict_16x16_init( h->param.cpu, h->predict_16x16 );
    x264_predict_8x8c_init( h->param.cpu, h->predict_8x8c );
    x264_predict_8x8_init( h->param.cpu, h->predict_8x8 );
    x264_predict_4x4_init( h->param.cpu, h->predict_4x4 );

    x264_pixel_init( h->param.cpu, &h->pixf );
    x264_dct_init( h->param.cpu, &h->dctf );
    x264_zigzag_init( h->param.cpu, &h->zigzagf, h->param.b_interlaced );
    x264_mc_init( h->param.cpu, &h->mc );
    x264_csp_init( h->param.cpu, h->param.i_csp, &h->csp );
    x264_quant_init( h, h->param.cpu, &h->quantf );
    x264_deblock_init( h->param.cpu, &h->loopf );
    x264_dct_init_weights();

    mbcmp_init( h );

    x264_log( h, X264_LOG_INFO, "using cpu capabilities: %s%s%s%s%s%s%s%s\n",
             param->cpu&X264_CPU_MMX ? "MMX " : "",
             param->cpu&X264_CPU_MMXEXT ? "MMXEXT " : "",
             param->cpu&X264_CPU_SSE ? "SSE " : "",
             param->cpu&X264_CPU_SSE2 ? "SSE2 " : "",
             param->cpu&X264_CPU_SSSE3 ? "SSSE3 " : "",
             param->cpu&X264_CPU_3DNOW ? "3DNow! " : "",
             param->cpu&X264_CPU_ALTIVEC ? "Altivec " : "",
             param->cpu ? "" : "none!" );

    h->out.i_nal = 0;
    h->out.i_bitstream = X264_MAX( 1000000, h->param.i_width * h->param.i_height * 4
        * ( h->param.rc.i_rc_method == X264_RC_ABR ? pow( 0.95, h->param.rc.i_qp_min )
          : pow( 0.95, h->param.rc.i_qp_constant ) * X264_MAX( 1, h->param.rc.f_ip_factor )));

    h->thread[0] = h;
    h->i_thread_num = 0;
    for( i = 1; i < h->param.i_threads; i++ )
        h->thread[i] = x264_malloc( sizeof(x264_t) );

    for( i = 0; i < h->param.i_threads; i++ )
    {
        if( i > 0 )
            *h->thread[i] = *h;
        h->thread[i]->fdec = x264_frame_pop_unused( h );
        h->thread[i]->out.p_bitstream = x264_malloc( h->out.i_bitstream );
        if( x264_macroblock_cache_init( h->thread[i] ) < 0 )
            return NULL;
    }

    if( x264_ratecontrol_new( h ) < 0 )
        return NULL;

#ifdef DEBUG_DUMP_FRAME
    {
        /* create or truncate the reconstructed video file */
        FILE *f = fopen( "fdec.yuv", "w" );
        if( f )
            fclose( f );
        else
        {
            x264_log( h, X264_LOG_ERROR, "can't write to fdec.yuv\n" );
            x264_free( h );
            return NULL;
        }
    }
#endif

    return h;
}

/****************************************************************************
 * x264_encoder_reconfig:
 ****************************************************************************/
int x264_encoder_reconfig( x264_t *h, x264_param_t *param )
{
#define COPY(var) h->param.var = param->var
    COPY( i_frame_reference ); // but never uses more refs than initially specified
    COPY( i_bframe_bias );
    if( h->param.i_scenecut_threshold >= 0 && param->i_scenecut_threshold >= 0 )
        COPY( i_scenecut_threshold ); // can't turn it on or off, only vary the threshold
    COPY( b_deblocking_filter );
    COPY( i_deblocking_filter_alphac0 );
    COPY( i_deblocking_filter_beta );
    COPY( analyse.intra );
    COPY( analyse.inter );
    COPY( analyse.i_direct_mv_pred );
    COPY( analyse.i_me_method );
    COPY( analyse.i_me_range );
    COPY( analyse.i_noise_reduction );
    COPY( analyse.i_subpel_refine );
    COPY( analyse.i_trellis );
    COPY( analyse.b_bidir_me );
    COPY( analyse.b_bframe_rdo );
    COPY( analyse.b_chroma_me );
    COPY( analyse.b_dct_decimate );
    COPY( analyse.b_fast_pskip );
    COPY( analyse.b_mixed_references );
    // can only twiddle these if they were enabled to begin with:
    if( h->pps->b_transform_8x8_mode )
        COPY( analyse.b_transform_8x8 );
    if( h->frames.i_max_ref1 > 1 )
        COPY( b_bframe_pyramid );
#undef COPY

    mbcmp_init( h );

    return x264_validate_parameters( h );
}

/* internal usage */
static void x264_nal_start( x264_t *h, int i_type, int i_ref_idc )
{
    x264_nal_t *nal = &h->out.nal[h->out.i_nal];

    nal->i_ref_idc = i_ref_idc;
    nal->i_type    = i_type;

    nal->i_payload= 0;
    nal->p_payload= &h->out.p_bitstream[bs_pos( &h->out.bs ) / 8];
}
static void x264_nal_end( x264_t *h )
{
    x264_nal_t *nal = &h->out.nal[h->out.i_nal];
    nal->i_payload = &h->out.p_bitstream[bs_pos( &h->out.bs ) / 8] - nal->p_payload;
    h->out.i_nal++;
}

/****************************************************************************
 * x264_encoder_headers:
 ****************************************************************************/
int x264_encoder_headers( x264_t *h, x264_nal_t **pp_nal, int *pi_nal )
{
    /* init bitstream context */
    h->out.i_nal = 0;
    bs_init( &h->out.bs, h->out.p_bitstream, h->out.i_bitstream );

    /* Put SPS and PPS */
    if( h->i_frame == 0 )
    {
        /* identify ourself */
        x264_nal_start( h, NAL_SEI, NAL_PRIORITY_DISPOSABLE );
        x264_sei_version_write( h, &h->out.bs );
        x264_nal_end( h );

        /* generate sequence parameters */
        x264_nal_start( h, NAL_SPS, NAL_PRIORITY_HIGHEST );
        x264_sps_write( &h->out.bs, h->sps );
        x264_nal_end( h );

        /* generate picture parameters */
        x264_nal_start( h, NAL_PPS, NAL_PRIORITY_HIGHEST );
        x264_pps_write( &h->out.bs, h->pps );
        x264_nal_end( h );
    }
    /* now set output*/
    *pi_nal = h->out.i_nal;
    *pp_nal = &h->out.nal[0];
    h->out.i_nal = 0;

    return 0;
}

static inline void x264_reference_build_list( x264_t *h, int i_poc )
{
    int i;
    int b_ok;

    /* build ref list 0/1 */
    h->i_ref0 = 0;
    h->i_ref1 = 0;
    for( i = 0; h->frames.reference[i]; i++ )
    {
        if( h->frames.reference[i]->i_poc < i_poc )
        {
            h->fref0[h->i_ref0++] = h->frames.reference[i];
        }
        else if( h->frames.reference[i]->i_poc > i_poc )
        {
            h->fref1[h->i_ref1++] = h->frames.reference[i];
        }
    }

    /* Order ref0 from higher to lower poc */
    do
    {
        b_ok = 1;
        for( i = 0; i < h->i_ref0 - 1; i++ )
        {
            if( h->fref0[i]->i_poc < h->fref0[i+1]->i_poc )
            {
                XCHG( x264_frame_t*, h->fref0[i], h->fref0[i+1] );
                b_ok = 0;
                break;
            }
        }
    } while( !b_ok );
    /* Order ref1 from lower to higher poc (bubble sort) for B-frame */
    do
    {
        b_ok = 1;
        for( i = 0; i < h->i_ref1 - 1; i++ )
        {
            if( h->fref1[i]->i_poc > h->fref1[i+1]->i_poc )
            {
                XCHG( x264_frame_t*, h->fref1[i], h->fref1[i+1] );
                b_ok = 0;
                break;
            }
        }
    } while( !b_ok );

    /* In the standard, a P-frame's ref list is sorted by frame_num.
     * We use POC, but check whether explicit reordering is needed */
    h->b_ref_reorder[0] =
    h->b_ref_reorder[1] = 0;
    if( h->sh.i_type == SLICE_TYPE_P )
    {
        for( i = 0; i < h->i_ref0 - 1; i++ )
            if( h->fref0[i]->i_frame_num < h->fref0[i+1]->i_frame_num )
            {
                h->b_ref_reorder[0] = 1;
                break;
            }
    }

    h->i_ref1 = X264_MIN( h->i_ref1, h->frames.i_max_ref1 );
    h->i_ref0 = X264_MIN( h->i_ref0, h->frames.i_max_ref0 );
    h->i_ref0 = X264_MIN( h->i_ref0, h->param.i_frame_reference ); // if reconfig() has lowered the limit
    h->i_ref0 = X264_MIN( h->i_ref0, 16 - h->i_ref1 );
    h->mb.pic.i_fref[0] = h->i_ref0;
    h->mb.pic.i_fref[1] = h->i_ref1;
}

static void x264_fdec_filter_row( x264_t *h, int mb_y )
{
    /* mb_y is the mb to be encoded next, not the mb to be filtered here */
    int b_hpel = h->fdec->b_kept_as_ref;
    int b_deblock = !h->sh.i_disable_deblocking_filter_idc;
    int b_end = mb_y == h->sps->i_mb_height;
    int min_y = mb_y - (1 << h->sh.b_mbaff);
#ifndef DEBUG_DUMP_FRAME
    b_deblock &= b_hpel;
#endif
    if( mb_y & h->sh.b_mbaff )
        return;
    if( min_y < 0 )
        return;

    if( !b_end )
    {
        int i, j;
        for( j=0; j<=h->sh.b_mbaff; j++ )
            for( i=0; i<3; i++ )
            {
                memcpy( h->mb.intra_border_backup[j][i],
                        h->fdec->plane[i] + ((mb_y*16 >> !!i) + j - 1 - h->sh.b_mbaff) * h->fdec->i_stride[i],
                        h->sps->i_mb_width*16 >> !!i );
            }
    }

    if( b_deblock )
    {
        int max_y = b_end ? h->sps->i_mb_height : mb_y;
        int y;
        for( y = min_y; y < max_y; y += (1 << h->sh.b_mbaff) )
            x264_frame_deblock_row( h, y );
    }

    if( b_hpel )
    {
        x264_frame_expand_border( h, h->fdec, min_y, b_end );
        x264_frame_filter( h->param.cpu, h->fdec, h->sh.b_mbaff, min_y, b_end );
        x264_frame_expand_border_filtered( h, h->fdec, min_y, b_end );
    }

    if( h->param.i_threads > 1 && h->fdec->b_kept_as_ref )
    {
        x264_frame_cond_broadcast( h->fdec, mb_y*16 + (b_end ? 10000 : -(X264_THREAD_HEIGHT << h->sh.b_mbaff)) );
    }
}

static inline void x264_reference_update( x264_t *h )
{
    int i;

    if( h->fdec->i_frame >= 0 )
        h->i_frame++;

    if( !h->fdec->b_kept_as_ref )
    {
        if( h->param.i_threads > 1 )
        {
            x264_frame_push_unused( h, h->fdec );
            h->fdec = x264_frame_pop_unused( h );
        }
        return;
    }

    /* move lowres copy of the image to the ref frame */
    for( i = 0; i < 4; i++)
    {
        XCHG( uint8_t*, h->fdec->lowres[i], h->fenc->lowres[i] );
        XCHG( uint8_t*, h->fdec->buffer_lowres[i], h->fenc->buffer_lowres[i] );
    }

    /* adaptive B decision needs a pointer, since it can't use the ref lists */
    if( h->sh.i_type != SLICE_TYPE_B )
        h->frames.last_nonb = h->fdec;

    /* move frame in the buffer */
    x264_frame_push( h->frames.reference, h->fdec );
    if( h->frames.reference[h->frames.i_max_dpb] )
        x264_frame_push_unused( h, x264_frame_shift( h->frames.reference ) );
    h->fdec = x264_frame_pop_unused( h );
}

static inline void x264_reference_reset( x264_t *h )
{
    while( h->frames.reference[0] )
        x264_frame_push_unused( h, x264_frame_pop( h->frames.reference ) );
    h->fdec->i_poc =
    h->fenc->i_poc = 0;
}

static inline void x264_slice_init( x264_t *h, int i_nal_type, int i_global_qp )
{
    /* ------------------------ Create slice header  ----------------------- */
    if( i_nal_type == NAL_SLICE_IDR )
    {
        x264_slice_header_init( h, &h->sh, h->sps, h->pps, h->i_idr_pic_id, h->i_frame_num, i_global_qp );

        /* increment id */
        h->i_idr_pic_id = ( h->i_idr_pic_id + 1 ) % 65536;
    }
    else
    {
        x264_slice_header_init( h, &h->sh, h->sps, h->pps, -1, h->i_frame_num, i_global_qp );

        /* always set the real higher num of ref frame used */
        h->sh.b_num_ref_idx_override = 1;
        h->sh.i_num_ref_idx_l0_active = h->i_ref0 <= 0 ? 1 : h->i_ref0;
        h->sh.i_num_ref_idx_l1_active = h->i_ref1 <= 0 ? 1 : h->i_ref1;
    }

    h->fdec->i_frame_num = h->sh.i_frame_num;

    if( h->sps->i_poc_type == 0 )
    {
        h->sh.i_poc_lsb = h->fdec->i_poc & ( (1 << h->sps->i_log2_max_poc_lsb) - 1 );
        h->sh.i_delta_poc_bottom = 0;   /* XXX won't work for field */
    }
    else if( h->sps->i_poc_type == 1 )
    {
        /* FIXME TODO FIXME */
    }
    else
    {
        /* Nothing to do ? */
    }

    x264_macroblock_slice_init( h );
}

static void x264_slice_write( x264_t *h )
{
    int i_skip;
    int mb_xy;
    int i;

    /* init stats */
    memset( &h->stat.frame, 0, sizeof(h->stat.frame) );

    /* Slice */
    x264_nal_start( h, h->i_nal_type, h->i_nal_ref_idc );

    /* Slice header */
    x264_slice_header_write( &h->out.bs, &h->sh, h->i_nal_ref_idc );
    if( h->param.b_cabac )
    {
        /* alignment needed */
        bs_align_1( &h->out.bs );

        /* init cabac */
        x264_cabac_context_init( &h->cabac, h->sh.i_type, h->sh.i_qp, h->sh.i_cabac_init_idc );
        x264_cabac_encode_init ( &h->cabac, h->out.bs.p, h->out.bs.p_end );
    }
    h->mb.i_last_qp = h->sh.i_qp;
    h->mb.i_last_dqp = 0;

    for( mb_xy = h->sh.i_first_mb, i_skip = 0; mb_xy < h->sh.i_last_mb; )
    {
        const int i_mb_y = mb_xy / h->sps->i_mb_width;
        const int i_mb_x = mb_xy % h->sps->i_mb_width;
        int mb_spos = bs_pos(&h->out.bs) + x264_cabac_pos(&h->cabac);

        if( i_mb_x == 0 )
            x264_fdec_filter_row( h, i_mb_y );

        /* load cache */
        x264_macroblock_cache_load( h, i_mb_x, i_mb_y );

        /* analyse parameters
         * Slice I: choose I_4x4 or I_16x16 mode
         * Slice P: choose between using P mode or intra (4x4 or 16x16)
         * */
        TIMER_START( i_mtime_analyse );
        x264_macroblock_analyse( h );
        TIMER_STOP( i_mtime_analyse );

        /* encode this macroblock -> be careful it can change the mb type to P_SKIP if needed */
        TIMER_START( i_mtime_encode );
        x264_macroblock_encode( h );
        TIMER_STOP( i_mtime_encode );

        TIMER_START( i_mtime_write );
        if( h->param.b_cabac )
        {
            if( mb_xy > h->sh.i_first_mb && !(h->sh.b_mbaff && (i_mb_y&1)) )
                x264_cabac_encode_terminal( &h->cabac, 0 );

            if( IS_SKIP( h->mb.i_type ) )
                x264_cabac_mb_skip( h, 1 );
            else
            {
                if( h->sh.i_type != SLICE_TYPE_I )
                    x264_cabac_mb_skip( h, 0 );
                x264_macroblock_write_cabac( h, &h->cabac );
            }
        }
        else
        {
            if( IS_SKIP( h->mb.i_type ) )
                i_skip++;
            else
            {
                if( h->sh.i_type != SLICE_TYPE_I )
                {
                    bs_write_ue( &h->out.bs, i_skip );  /* skip run */
                    i_skip = 0;
                }
                x264_macroblock_write_cavlc( h, &h->out.bs );
            }
        }
        TIMER_STOP( i_mtime_write );

#if VISUALIZE
        if( h->param.b_visualize )
            x264_visualize_mb( h );
#endif

        /* save cache */
        x264_macroblock_cache_save( h );

        /* accumulate mb stats */
        h->stat.frame.i_mb_count[h->mb.i_type]++;
        if( !IS_SKIP(h->mb.i_type) && !IS_INTRA(h->mb.i_type) && !IS_DIRECT(h->mb.i_type) )
        {
            if( h->mb.i_partition != D_8x8 )
                h->stat.frame.i_mb_count_size[ x264_mb_partition_pixel_table[ h->mb.i_partition ] ] += 4;
            else
                for( i = 0; i < 4; i++ )
                    h->stat.frame.i_mb_count_size[ x264_mb_partition_pixel_table[ h->mb.i_sub_partition[i] ] ] ++;
            if( h->param.i_frame_reference > 1 )
            {
                for( i = 0; i < 4; i++ )
                {
                    int i_ref = h->mb.cache.ref[0][ x264_scan8[4*i] ];
                    if( i_ref >= 0 )
                        h->stat.frame.i_mb_count_ref[i_ref] ++;
                }
            }
        }
        if( h->mb.i_cbp_luma && !IS_INTRA(h->mb.i_type) )
        {
            h->stat.frame.i_mb_count_8x8dct[0] ++;
            h->stat.frame.i_mb_count_8x8dct[1] += h->mb.b_transform_8x8;
        }

        if( h->mb.b_variable_qp )
            x264_ratecontrol_mb(h, bs_pos(&h->out.bs) + x264_cabac_pos(&h->cabac) - mb_spos);

        if( h->sh.b_mbaff )
        {
            if( (i_mb_y&1) && i_mb_x == h->sps->i_mb_width - 1 )
                mb_xy++;
            else if( i_mb_y&1 )
                mb_xy += 1 - h->sps->i_mb_width;
            else
                mb_xy += h->sps->i_mb_width;
        }
        else
            mb_xy++;
    }

    if( h->param.b_cabac )
    {
        /* end of slice */
        x264_cabac_encode_terminal( &h->cabac, 1 );
    }
    else if( i_skip > 0 )
    {
        bs_write_ue( &h->out.bs, i_skip );  /* last skip run */
    }

    if( h->param.b_cabac )
    {
        x264_cabac_encode_flush( &h->cabac );
        h->out.bs.p = h->cabac.p;
    }
    else
    {
        /* rbsp_slice_trailing_bits */
        bs_rbsp_trailing( &h->out.bs );
    }

    x264_nal_end( h );

    /* Compute misc bits */
    h->stat.frame.i_misc_bits = bs_pos( &h->out.bs )
                              + NALU_OVERHEAD * 8