h264.c

VLC Player Source Code

    /* Append the block */
    if( p_frag )
        block_ChainAppend( &p_sys->p_frame, p_frag );

    *pb_used_ts = false;
    if( p_sys->i_frame_dts < 0 && p_sys->i_frame_pts < 0 )
    {
        p_sys->i_frame_dts = i_frag_dts;
        p_sys->i_frame_pts = i_frag_pts;
        *pb_used_ts = true;
    }
    return p_pic;
}

static block_t *OutputPicture( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_pic;

    if( !p_sys->b_header && p_sys->slice.i_frame_type != BLOCK_FLAG_TYPE_I)
        return NULL;

    if( p_sys->slice.i_frame_type == BLOCK_FLAG_TYPE_I && p_sys->b_sps && p_sys->b_pps )
    {
        block_t *p_list = NULL;
        int i;

        for( i = 0; i < SPS_MAX; i++ )
        {
            if( p_sys->pp_sps[i] )
                block_ChainAppend( &p_list, block_Duplicate( p_sys->pp_sps[i] ) );
        }
        for( i = 0; i < PPS_MAX; i++ )
        {
            if( p_sys->pp_pps[i] )
                block_ChainAppend( &p_list, block_Duplicate( p_sys->pp_pps[i] ) );
        }
        if( p_list )
            p_sys->b_header = true;

        block_ChainAppend( &p_list, p_sys->p_frame );
        p_pic = block_ChainGather( p_list );
    }
    else
    {
        p_pic = block_ChainGather( p_sys->p_frame );
    }
    p_pic->i_dts = p_sys->i_frame_dts;
    p_pic->i_pts = p_sys->i_frame_pts;
    p_pic->i_length = 0;    /* FIXME */
    p_pic->i_flags |= p_sys->slice.i_frame_type;

    p_sys->slice.i_frame_type = 0;
    p_sys->p_frame = NULL;
    p_sys->i_frame_dts = -1;
    p_sys->i_frame_pts = -1;
    p_sys->b_slice = false;

    return p_pic;
}

static void PutSPS( decoder_t *p_dec, block_t *p_frag )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    uint8_t *pb_dec = NULL;
    int     i_dec = 0;
    bs_t s;
    int i_tmp;
    int i_sps_id;

    CreateDecodedNAL( &pb_dec, &i_dec, &p_frag->p_buffer[5],
                     p_frag->i_buffer - 5 );

    bs_init( &s, pb_dec, i_dec );
    /* Skip profile(8), constraint_set012, reserver(5), level(8) */
    bs_skip( &s, 8 + 1+1+1 + 5 + 8 );
    /* sps id */
    i_sps_id = bs_read_ue( &s );
    if( i_sps_id >= SPS_MAX )
    {
        msg_Warn( p_dec, "invalid SPS (sps_id=%d)", i_sps_id );
        free( pb_dec );
        block_Release( p_frag );
        return;
    }

    /* Skip i_log2_max_frame_num */
    p_sys->i_log2_max_frame_num = bs_read_ue( &s );
    if( p_sys->i_log2_max_frame_num > 12)
        p_sys->i_log2_max_frame_num = 12;
    /* Read poc_type */
    p_sys->i_pic_order_cnt_type = bs_read_ue( &s );
    if( p_sys->i_pic_order_cnt_type == 0 )
    {
        /* skip i_log2_max_poc_lsb */
        p_sys->i_log2_max_pic_order_cnt_lsb = bs_read_ue( &s );
        if( p_sys->i_log2_max_pic_order_cnt_lsb > 12 )
            p_sys->i_log2_max_pic_order_cnt_lsb = 12;
    }
    else if( p_sys->i_pic_order_cnt_type == 1 )
    {
        int i_cycle;
        /* skip b_delta_pic_order_always_zero */
        p_sys->i_delta_pic_order_always_zero_flag = bs_read( &s, 1 );
        /* skip i_offset_for_non_ref_pic */
        bs_read_se( &s );
        /* skip i_offset_for_top_to_bottom_field */
        bs_read_se( &s );
        /* read i_num_ref_frames_in_poc_cycle */
        i_cycle = bs_read_ue( &s );
        if( i_cycle > 256 ) i_cycle = 256;
        while( i_cycle > 0 )
        {
            /* skip i_offset_for_ref_frame */
            bs_read_se(&s );
            i_cycle--;
        }
    }
    /* i_num_ref_frames */
    bs_read_ue( &s );
    /* b_gaps_in_frame_num_value_allowed */
    bs_skip( &s, 1 );

    /* Read size */
    p_dec->fmt_out.video.i_width  = 16 * ( bs_read_ue( &s ) + 1 );
    p_dec->fmt_out.video.i_height = 16 * ( bs_read_ue( &s ) + 1 );

    /* b_frame_mbs_only */
    p_sys->b_frame_mbs_only = bs_read( &s, 1 );
    if( p_sys->b_frame_mbs_only == 0 )
    {
        bs_skip( &s, 1 );
    }
    /* b_direct8x8_inference */
    bs_skip( &s, 1 );

    /* crop */
    i_tmp = bs_read( &s, 1 );
    if( i_tmp )
    {
        /* left */
        bs_read_ue( &s );
        /* right */
        bs_read_ue( &s );
        /* top */
        bs_read_ue( &s );
        /* bottom */
        bs_read_ue( &s );
    }

    /* vui */
    i_tmp = bs_read( &s, 1 );
    if( i_tmp )
    {
        /* read the aspect ratio part if any FIXME check it */
        i_tmp = bs_read( &s, 1 );
        if( i_tmp )
        {
            static const struct { int w, h; } sar[17] =
            {
                { 0,   0 }, { 1,   1 }, { 12, 11 }, { 10, 11 },
                { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 },
                { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 },
                { 64, 33 }, { 160,99 }, {  4,  3 }, {  3,  2 },
                {  2,  1 },
            };
            int i_sar = bs_read( &s, 8 );
            int w, h;

            if( i_sar < 17 )
            {
                w = sar[i_sar].w;
                h = sar[i_sar].h;
            }
            else if( i_sar == 255 )
            {
                w = bs_read( &s, 16 );
                h = bs_read( &s, 16 );
            }
            else
            {
                w = 0;
                h = 0;
            }

            if( h != 0 )
                p_dec->fmt_out.video.i_aspect = (int64_t)VOUT_ASPECT_FACTOR *
                        ( w * p_dec->fmt_out.video.i_width ) /
                        ( h * p_dec->fmt_out.video.i_height);
            else
                p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR;
        }
    }

    free( pb_dec );

    /* We have a new SPS */
    if( !p_sys->b_sps )
        msg_Dbg( p_dec, "found NAL_SPS (sps_id=%d)", i_sps_id );
    p_sys->b_sps = true;

    if( p_sys->pp_sps[i_sps_id] )
        block_Release( p_sys->pp_sps[i_sps_id] );
    p_sys->pp_sps[i_sps_id] = p_frag;
}

static void PutPPS( decoder_t *p_dec, block_t *p_frag )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    bs_t s;
    int i_pps_id;
    int i_sps_id;

    bs_init( &s, &p_frag->p_buffer[5], p_frag->i_buffer - 5 );
    i_pps_id = bs_read_ue( &s ); // pps id
    i_sps_id = bs_read_ue( &s ); // sps id
    if( i_pps_id >= PPS_MAX || i_sps_id >= SPS_MAX )
    {
        msg_Warn( p_dec, "invalid PPS (pps_id=%d sps_id=%d)", i_pps_id, i_sps_id );
        block_Release( p_frag );
        return;
    }
    bs_skip( &s, 1 ); // entropy coding mode flag
    p_sys->i_pic_order_present_flag = bs_read( &s, 1 );
    /* TODO */

    /* We have a new PPS */
    if( !p_sys->b_pps )
        msg_Dbg( p_dec, "found NAL_PPS (pps_id=%d sps_id=%d)", i_pps_id, i_sps_id );
    p_sys->b_pps = true;

    if( p_sys->pp_pps[i_pps_id] )
        block_Release( p_sys->pp_pps[i_pps_id] );
    p_sys->pp_pps[i_pps_id] = p_frag;
}

static void ParseSlice( decoder_t *p_dec, bool *pb_new_picture, slice_t *p_slice,
                        int i_nal_ref_idc, int i_nal_type, const block_t *p_frag )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    uint8_t *pb_dec;
    int i_dec;
    int i_first_mb, i_slice_type;
    slice_t slice;
    bs_t s;

    /* do not convert the whole frame */
    CreateDecodedNAL( &pb_dec, &i_dec, &p_frag->p_buffer[5],
                     __MIN( p_frag->i_buffer - 5, 60 ) );
    bs_init( &s, pb_dec, i_dec );

    /* first_mb_in_slice */
    i_first_mb = bs_read_ue( &s );

    /* slice_type */
    switch( (i_slice_type = bs_read_ue( &s )) )
    {
    case 0: case 5:
        slice.i_frame_type = BLOCK_FLAG_TYPE_P;
        break;
    case 1: case 6:
        slice.i_frame_type = BLOCK_FLAG_TYPE_B;
        break;
    case 2: case 7:
        slice.i_frame_type = BLOCK_FLAG_TYPE_I;
        break;
    case 3: case 8: /* SP */
        slice.i_frame_type = BLOCK_FLAG_TYPE_P;
        break;
    case 4: case 9:
        slice.i_frame_type = BLOCK_FLAG_TYPE_I;
        break;
    default:
        slice.i_frame_type = 0;
        break;
    }

    /* */
    slice.i_nal_type = i_nal_type;
    slice.i_nal_ref_idc = i_nal_ref_idc;

    slice.i_pic_parameter_set_id = bs_read_ue( &s );
    slice.i_frame_num = bs_read( &s, p_sys->i_log2_max_frame_num + 4 );

    slice.i_field_pic_flag = 0;
    slice.i_bottom_field_flag = -1;
    if( !p_sys->b_frame_mbs_only )
    {
        /* field_pic_flag */
        slice.i_field_pic_flag = bs_read( &s, 1 );
        if( slice.i_field_pic_flag )
            slice.i_bottom_field_flag = bs_read( &s, 1 );
    }

    slice.i_idr_pic_id = p_sys->slice.i_idr_pic_id;
    if( slice.i_nal_type == NAL_SLICE_IDR )
        slice.i_idr_pic_id = bs_read_ue( &s );

    slice.i_pic_order_cnt_lsb = -1;
    slice.i_delta_pic_order_cnt_bottom = -1;
    slice.i_delta_pic_order_cnt0 = 0;
    slice.i_delta_pic_order_cnt1 = 0;
    if( p_sys->i_pic_order_cnt_type == 0 )
    {
        slice.i_pic_order_cnt_lsb = bs_read( &s, p_sys->i_log2_max_pic_order_cnt_lsb + 4 );
        if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
            slice.i_delta_pic_order_cnt_bottom = bs_read_se( &s );
    }
    else if( (p_sys->i_pic_order_cnt_type == 1) &&
             (!p_sys->i_delta_pic_order_always_zero_flag) )
    {
        slice.i_delta_pic_order_cnt0 = bs_read_se( &s );
        if( p_sys->i_pic_order_present_flag && !slice.i_field_pic_flag )
            slice.i_delta_pic_order_cnt1 = bs_read_se( &s );
    }
    free( pb_dec );

    /* Detection of the first VCL NAL unit of a primary coded picture
     * (cf. 7.4.1.2.4) */
    bool b_pic = false;
    if( slice.i_frame_num != p_sys->slice.i_frame_num ||
        slice.i_pic_parameter_set_id != p_sys->slice.i_pic_parameter_set_id ||
        slice.i_field_pic_flag != p_sys->slice.i_field_pic_flag ||
        slice.i_nal_ref_idc != p_sys->slice.i_nal_ref_idc )
        b_pic = true;
    if( (slice.i_bottom_field_flag != -1) &&
        (p_sys->slice.i_bottom_field_flag != -1) &&
        (slice.i_bottom_field_flag != p_sys->slice.i_bottom_field_flag) )
        b_pic = true;
    if( p_sys->i_pic_order_cnt_type == 0 &&
        ( slice.i_pic_order_cnt_lsb != p_sys->slice.i_pic_order_cnt_lsb ||
          slice.i_delta_pic_order_cnt_bottom != p_sys->slice.i_delta_pic_order_cnt_bottom ) )
        b_pic = true;
    else if( p_sys->i_pic_order_cnt_type == 1 &&
             ( slice.i_delta_pic_order_cnt0 != p_sys->slice.i_delta_pic_order_cnt0 ||
               slice.i_delta_pic_order_cnt1 != p_sys->slice.i_delta_pic_order_cnt1 ) )
        b_pic = true;
    if( ( slice.i_nal_type == NAL_SLICE_IDR || p_sys->slice.i_nal_type == NAL_SLICE_IDR ) &&
        ( slice.i_nal_type != p_sys->slice.i_nal_type || slice.i_idr_pic_id != p_sys->slice.i_idr_pic_id ) )
            b_pic = true;

    /* */
    *pb_new_picture = b_pic;
    *p_slice = slice;
}