Biegral Blog

// 本函数的主要功能是对参数进行修改（赋值/重新赋值）
 x264_t *x264_encoder_open   ( x264_param_t *param )
{
    x264_t *h = x264_malloc( sizeof( x264_t ) );
    int i;

	// 初始置0
    memset( h, 0, sizeof( x264_t ) );

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

    // x264_validate_parameters对参数进行判断并赋值
	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->out.i_nal = 0;
    h->out.i_bitstream = X264_MAX( 1000000, h->param.i_width * h->param.i_height * 1.7
        * ( h->param.rc.i_rc_method == X264_RC_ABR ? pow( 0.5, h->param.rc.i_qp_min )
          : pow( 0.5, h->param.rc.i_qp_constant ) * X264_MAX( 1, h->param.rc.f_ip_factor )));
    h->out.p_bitstream = x264_malloc( h->out.i_bitstream );

    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 );

    x264_cqm_init( h );
    
    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->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 + 1;
    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 );

    for( i = 0; i < X264_BFRAME_MAX + 3; i++ )
    {
        h->frames.current[i] = NULL;
        h->frames.next[i]    = NULL;
        h->frames.unused[i]  = NULL;
    }
    for( i = 0; i < 1 + h->frames.i_delay; i++ )
    {
        h->frames.unused[i] =  x264_frame_new( h );
        if( !h->frames.unused[i] )
            return NULL;
    }
    for( i = 0; i < h->frames.i_max_dpb; i++ )
    {
        h->frames.reference[i] = x264_frame_new( h );
        if( !h->frames.reference[i] )
            return NULL;
    }
    h->frames.reference[h->frames.i_max_dpb] = NULL;
    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;

    h->fdec = h->frames.reference[0];

    if( x264_macroblock_cache_init( h ) < 0 )
        return NULL;
    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_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 );

    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) );

    /* rate control */
    if( x264_ratecontrol_new( h ) < 0 )
        return NULL;

    x264_log( h, X264_LOG_INFO, "using cpu capabilities %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_3DNOW ? "3DNow! " : "",
             param->cpu&X264_CPU_ALTIVEC ? "Altivec " : "" );

    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) );

#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;
}

       从上面可以看到，x264_encoder_open调用了很多其他的函数，如果需要看，再看.