encoder.c

X264的纯C语言的的原码

///    {
        /* 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 );

    }
    else
    {*/
        /* rbsp_slice_trailing_bits */
        bs_rbsp_trailing( &h->out.bs );
 ///   }

    x264_nal_end( h );//NAL单元编码结束

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

    return 0;
}

static inline int x264_slices_write( x264_t *h )
{
    int i_frame_size;

	fprintf(stderr,"x264_slices_write:h->param.b_visualize=%d\n",h->param.b_visualize);//add
    fprintf(stderr,"x264_slices_write:h->param.i_threads=%d\n",h->param.i_threads);//add
	fprintf(stderr,"x264_slices_write:h->out.nal[h->out.i_nal-1].i_payload=%d\n",h->out.nal[h->out.i_nal-1].i_payload);//add
//	fprintf(stderr,"x264_slices_write:hout=%d\n",hout);//add
//	fprintf(stderr,"x264_slices_write:hout=%d\n",hout);//add
//	fprintf(stderr,"x264_slices_write:hout=%d\n",hout);//add
//	fprintf(stderr,"x264_slices_write:hout=%d\n",hout);//add

#if VISUALIZE
    if( h->param.b_visualize )
        x264_visualize_init( h );
#endif

    if( h->param.i_threads == 1 )
    {
        x264_ratecontrol_threads_start( h );
        x264_slice_write( h );
        i_frame_size = h->out.nal[h->out.i_nal-1].i_payload;
    }
    else
    {
        int i_nal = h->out.i_nal;
        int i_bs_size = h->out.i_bitstream / h->param.i_threads;
        int i;
        /* duplicate contexts */
        for( i = 0; i < h->param.i_threads; i++ )
        {
            x264_t *t = h->thread[i];
            if( i > 0 )
            {
                memcpy( t, h, sizeof(x264_t) );
                t->out.p_bitstream += i*i_bs_size;
                bs_init( &t->out.bs, t->out.p_bitstream, i_bs_size );
                t->i_thread_num = i;
            }
            t->sh.i_first_mb = (i    * h->sps->i_mb_height / h->param.i_threads) * h->sps->i_mb_width;
            t->sh.i_last_mb = ((i+1) * h->sps->i_mb_height / h->param.i_threads) * h->sps->i_mb_width;
            t->out.i_nal = i_nal + i;
        }
        x264_ratecontrol_threads_start( h );

        /* dispatch */
#ifdef HAVE_PTHREAD
        {
            pthread_t handles[X264_SLICE_MAX];
            for( i = 0; i < h->param.i_threads; i++ )
                pthread_create( &handles[i], NULL, (void*)x264_slice_write, (void*)h->thread[i] );
            for( i = 0; i < h->param.i_threads; i++ )
                pthread_join( handles[i], NULL );
        }
#else
        for( i = 0; i < h->param.i_threads; i++ )
            x264_slice_write( h->thread[i] );
#endif

        /* merge contexts */
        i_frame_size = h->out.nal[i_nal].i_payload;
        for( i = 1; i < h->param.i_threads; i++ )
        {
            int j;
            x264_t *t = h->thread[i];
            h->out.nal[i_nal+i] = t->out.nal[i_nal+i];
            i_frame_size += t->out.nal[i_nal+i].i_payload;
            // all entries in stat.frame are ints
            for( j = 0; j < sizeof(h->stat.frame) / sizeof(int); j++ )
                ((int*)&h->stat.frame)[j] += ((int*)&t->stat.frame)[j];
        }
        h->out.i_nal = i_nal + h->param.i_threads;
    }

#if VISUALIZE
    if( h->param.b_visualize )
    {
        x264_visualize_show( h );
        x264_visualize_close( h );
    }
#endif

    return i_frame_size;
}

/****************************************************************************
 * x264_encoder_encode:
 *  XXX: i_poc   : is the poc of the current given picture
 *       i_frame : is the number of the frame being coded
 *  ex:  type frame poc
 *       I      0   2*0
 *       P      1   2*3
 *       B      2   2*1
 *       B      3   2*2
 *       P      4   2*6
 *       B      5   2*4
 *       B      6   2*5
 ****************************************************************************/
int     x264_encoder_encode( x264_t *h,
                             x264_nal_t **pp_nal, int *pi_nal,
                             x264_picture_t *pic_in,
                             x264_picture_t *pic_out )
{
    x264_frame_t   *frame_psnr = h->fdec; /* just to keep the current decoded frame for psnr calculation */
    int     i_nal_type;
    int     i_nal_ref_idc;
    int     i_slice_type;
    int     i_frame_size;
int a;//add
    int i;

    int   i_global_qp;

    char psz_message[80];

    /* no data out */
    *pi_nal = 0;
    *pp_nal = NULL;

    fprintf(stderr,"x264_encoder_encode:h->i_frame=%d\n",h->i_frame);//add
	fprintf(stderr,"x264_encoder_encode:h->i_frame_num=%d\n",h->i_frame_num);//add
	fprintf(stderr,"x264_encoder_encode:h->i_frame_offset=%d\n",h->i_frame_offset);//add
	fprintf(stderr,"x264_encoder_encode:h->i_idr_pic_id=%d\n",h->i_idr_pic_id);//add
	fprintf(stderr,"x264_encoder_encode:h->i_nal_ref_idc=%d\n",h->i_nal_ref_idc);//add
	fprintf(stderr,"x264_encoder_encode:h->i_nal_type=%d\n",h->i_nal_type);//add
	fprintf(stderr,"x264_encoder_encode:h->i_poc=%d\n",h->i_poc);//add
	fprintf(stderr,"x264_encoder_encode:h->i_poc_lsb=%d\n",h->i_poc_lsb);//add
	fprintf(stderr,"x264_encoder_encode:h->i_poc_msb=%d\n",h->i_poc_msb);//add
	fprintf(stderr,"x264_encoder_encode:h->i_ref0=%d\n",h->i_ref0);//add
	fprintf(stderr,"x264_encoder_encode:h->i_ref1=%d\n",h->i_ref1);//add
	fprintf(stderr,"x264_encoder_encode:h->i_thread_num=%d\n",h->i_thread_num);//add
//	fprintf(stderr,"x264_encoder_encode:h->i_nal_type=%d\n",h->i_nal_type);//add


    /* ------------------- Setup new frame from picture -------------------- */
///    TIMER_START( i_mtime_encode_frame );
    if( pic_in != NULL )
    {
        /* 1: Copy the picture to a frame and move it to a buffer *///将图片复制到一帧中去并且移动到一个缓冲器中
        x264_frame_t *fenc = x264_frame_get( h->frames.unused );//(1)
		fprintf(stderr,"x264_encoder_encode:fenc=%d\n",*fenc);//add

        x264_frame_copy_picture( h, fenc, pic_in );//(2)

        if( h->param.i_width % 16 || h->param.i_height % 16 )
            x264_frame_expand_border_mod16( h, fenc );

        fenc->i_frame = h->frames.i_input++;//(3)

        x264_frame_put( h->frames.next, fenc );//(4)

        if( h->frames.b_have_lowres )
            x264_frame_init_lowres( h->param.cpu, fenc );//(1)(2)(3)(4)里面包含低象素的扩展，很多for循环，应该是抽头计算和半精度象素的扩展，要认真看！

        if( h->frames.i_input <= h->frames.i_delay )
        {
            /* Nothing yet to encode */
            /* waiting for filling bframe buffer */
            pic_out->i_type = X264_TYPE_AUTO;
            return 0;
        }
    }

    if( h->frames.current[0] == NULL )
    {
        int bframes = 0;
        /* 2: Select frame types *///选择帧类型
        if( h->frames.next[0] == NULL )
            return 0;

        x264_slicetype_decide( h );//对slice类型的判定，里面也要看一下！

        /* 3: move some B-frames and 1 non-B to encode queue *///移动一些B帧和一个非B帧到编码队列中
        while( IS_X264_TYPE_B( h->frames.next[bframes]->i_type ) )
            bframes++;
        x264_frame_put( h->frames.current, x264_frame_get( &h->frames.next[bframes] ) );//这主要是因为B帧必须等后面的非B帧编码结束后才能编码，所以把暂时不编的一系列B帧存入队列中，一直到非B帧取出进行编码之后再进行前面的B帧编码
        /* FIXME: when max B-frames > 3, BREF may no longer be centered after GOP closing */
        if( h->param.b_bframe_pyramid && bframes > 1 )
        {
            x264_frame_t *mid = x264_frame_get( &h->frames.next[bframes/2] );
            mid->i_type = X264_TYPE_BREF;
            x264_frame_put( h->frames.current, mid );
            bframes--;
        }
        while( bframes-- )
            x264_frame_put( h->frames.current, x264_frame_get( h->frames.next ) );
    }
///    TIMER_STOP( i_mtime_encode_frame );

    /* ------------------- Get frame to be encoded ------------------------- *///获得要被编码的帧
    /* 4: get picture to encode */
    h->fenc = x264_frame_get( h->frames.current );
    if( h->fenc == NULL )
    {
        /* Nothing yet to encode (ex: waiting for I/P with B frames) */
        /* waiting for filling bframe buffer */
        pic_out->i_type = X264_TYPE_AUTO;
        return 0;
    }

do_encode://编码

    if( h->fenc->i_type == X264_TYPE_IDR )
    {
        h->frames.i_last_idr = h->fenc->i_frame;
    }

    /* ------------------- Setup frame context ----------------------------- *///设置帧上下文
    /* 5: Init data dependant of frame type *///初始化帧类型
///    TIMER_START( i_mtime_encode_frame );
    if( h->fenc->i_type == X264_TYPE_IDR )
    {
        /* reset ref pictures */
        x264_reference_reset( h );

        i_nal_type    = NAL_SLICE_IDR;
        i_nal_ref_idc = NAL_PRIORITY_HIGHEST;
        i_slice_type = SLICE_TYPE_I;
    }
    else if( h->fenc->i_type == X264_TYPE_I )
    {
        i_nal_type    = NAL_SLICE;
        i_nal_ref_idc = NAL_PRIORITY_HIGH; /* Not completely true but for now it is (as all I/P are kept as ref)*/
        i_slice_type = SLICE_TYPE_I;
    }
    else if( h->fenc->i_type == X264_TYPE_P )
    {
        i_nal_type    = NAL_SLICE;
        i_nal_ref_idc = NAL_PRIORITY_HIGH; /* Not completely true but for now it is (as all I/P are kept as ref)*/
        i_slice_type = SLICE_TYPE_P;
    }
    else if( h->fenc->i_type == X264_TYPE_BREF )
    {
        i_nal_type    = NAL_SLICE;
        i_nal_ref_idc = NAL_PRIORITY_HIGH; /* maybe add MMCO to forget it? -> low */
        i_slice_type = SLICE_TYPE_B;
    }
    else    /* B frame */
    {
        i_nal_type    = NAL_SLICE;
        i_nal_ref_idc = NAL_PRIORITY_DISPOSABLE;
        i_slice_type = SLICE_TYPE_B;
    }

    h->fdec->i_poc =
    h->fenc->i_poc = 2 * (h->fenc->i_frame - h->frames.i_last_idr);
    h->fdec->i_type = h->fenc->i_type;
    h->fdec->i_frame = h->fenc->i_frame;
    h->fenc->b_kept_as_ref =
    h->fdec->b_kept_as_ref = i_nal_ref_idc != NAL_PRIORITY_DISPOSABLE;



    /* ------------------- Init                ----------------------------- */
    /* build ref list 0/1 */
    x264_reference_build_list( h, h->fdec->i_poc, i_slice_type );//建立list0和list1参考列表

    /* Init the rate control */
    x264_ratecontrol_start( h, i_slice_type, h->fenc->i_qpplus1 );//比特（bit）率控制初始化
    i_global_qp = x264_ratecontrol_qp( h );

    pic_out->i_qpplus1 =
    h->fdec->i_qpplus1 = i_global_qp + 1;

    if( i_slice_type == SLICE_TYPE_B )
        x264_macroblock_bipred_init( h );

    /* ------------------------ Create slice header  ----------------------- */
    x264_slice_init( h, i_nal_type, i_slice_type, i_global_qp );//创建slice的头部数据

    if( h->fenc->b_kept_as_ref )
        h->i_frame_num++;

    /* ---------------------- Write the bitstream -------------------------- *///写入bit流
    /* Init bitstream context *///初始化bit流上下文
    h->out.i_nal = 0;
    bs_init( &h->out.bs, h->out.p_bitstream, h->out.i_bitstream );

    if(h->param.b_aud){
        int pic_type;

        if(i_slice_type == SLICE_TYPE_I)
            pic_type = 0;
        else if(i_slice_type == SLICE_TYPE_P)
            pic_type = 1;
        else if(i_slice_type == SLICE_TYPE_B)
            pic_type = 2;
        else
            pic_type = 7;

        x264_nal_start(h, NAL_AUD, NAL_PRIORITY_DISPOSABLE);
        bs_write(&h->out.bs, 3, pic_type);
        bs_rbsp_trailing(&h->out.bs);
        x264_nal_end(h);
    }

    h->i_nal_type = i_nal_type;
    h->i_nal_ref_idc = i_nal_ref_idc;

    /* Write SPS and PPS *///写入序列参数信号和图片参数信号
    if( i_nal_type == NAL_SLICE_IDR && h->param.b_repeat_headers )
    {
        if( h->fenc->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 );
    }

    /* Write frame */