mp4dutil.c

Intel提供的在Sitsang等嵌入式开发平台上使用Linux操作系统

/******************************************************************************
//               INTEL CORPORATION PROPRIETARY INFORMATION
//  This software is supplied under the terms of a license agreement or
//  nondisclosure agreement with Intel Corporation and may not be copied
//  or disclosed except in accordance with the terms of that agreement.
//        Copyright (c) 2003 Intel Corporation. All Rights Reserved.
//
//  Description:    Utility functions of MPEG-4 video decoder sample code for
//                  Intel(R) Integrated Performance Primitives.
//  Functions List:
//		copy_mb_from_ref_plane()
//		lookup_uvmv_mpeg4()
//		expand_frame_dec_mpeg4()
//      set_ref_frame_dec_mpeg4()
//      search_next_sc_mpeg4()
//      insert_sc_mpeg4()
******************************************************************************/

#include "sampmp4.h"

/******************************************************************************
// Name:        copy_mb_from_ref_plane
// Desicription:
//              Copy macroblock pixels from referrence plane to current plane
//  Input Arguments:
//      src_y       - Pointer to the luminance block in referrence plane
//      src_cb      - Pointer to the chrominance (Cb) block in referrence plane
//      src_cr      - Pointer to the chrominance (Cr) block in referrence plane
//      src_y_step  - step of referrence luminance plane
//      src_cb_step - step of referrence chrominance (Cb) plane
//      src_cr_step - step of referrence chrominance (Cr) plane
//      dst_y_step  - step of current luminance plane
//      dst_cb_step - step of current chrominance (Cb) plane
//      dst_cr_step - step of current chrominance (Cr) plane
//
//  Output Arguments:
//      dst_y       - Pointer to the luminance block in current plane
//      dst_cb      - Pointer to the chrominance (Cb) block in current plane
//      dst_cr      - Pointer to the chrominance (Cr) block in current plane
//      SAMPLE_STATUS_NOERR     If succeeds
// Note:  
******************************************************************************/
sample_status copy_mb_from_ref_plane
(const Ipp8u *src_y,  int src_y_step, const Ipp8u *src_cb, int src_cb_step,
 const Ipp8u *src_cr, int src_cr_step,      Ipp8u *dst_y,  int dst_y_step,
       Ipp8u *dst_cb, int dst_cb_step,      Ipp8u *dst_cr, int dst_cr_step) 
{
    int i, j;

    /* Copy Y MB from fwd_ref_mb */
    for (i = 0; i < SAMPLE_VIDEO_MB_SIZE; i++) {
        for (j=0; j < SAMPLE_VIDEO_MB_SIZE; j++) {
            dst_y[j] = src_y[j];
        }
        src_y += src_y_step;
        dst_y += dst_y_step;                     
    }

    /* Copy UV MB from fwd_ref_mb */
    for (i = 0; i < SAMPLE_VIDEO_BLOCK_SIZE; i ++) {
        for (j = 0; j < SAMPLE_VIDEO_BLOCK_SIZE; j++) {
            dst_cb[j] = src_cb[j];
            dst_cr[j] = src_cr[j];
        }

        src_cb += src_cb_step;
        dst_cb += dst_cb_step;

        src_cr += src_cr_step;
        dst_cr += dst_cr_step;
    }
    
    return SAMPLE_STATUS_NOERR;
}

/*****************************************************************************
// Name:            lookup_uvmv_mpeg4()
// Description:     Look up the motion vector of chrominace block based on the
//                  motion vector of luminance block.
// Input Arguments: 
//      mv_lum      Pointer to the Motion Vector of Luminance block.
//                  (1st lumianance block in macroblock)
//      mb_type     macroblock type
// Output Arguments:
//      mv_chr      Pointer to the Motion Vector of Luminance block.
// Returns:
//      SAMPLE_STATUS_NOERR     If succeeds
// Notes:
******************************************************************************/
sample_status lookup_uvmv_mpeg4
(IppMotionVector *mv_lum, IppMotionVector *mv_chr, int mb_type)
{
    int     k ;
    int     dx, dy;

    if ((IPP_VIDEO_INTER4V == mb_type) || (IPP_VIDEO_DIRECT == mb_type)) {
        dx = mv_lum[0].dx + mv_lum[1].dx + mv_lum[2].dx + mv_lum[3].dx;
        dy = mv_lum[0].dy + mv_lum[1].dy + mv_lum[2].dy + mv_lum[3].dy;

        if (0 == dx) {                                         
            mv_chr->dx = 0;                                             
        } else if (0 < dx) {                                     
            k = dx & 0x0f;                                  
            mv_chr->dx = (Ipp16s)((dx >> 4) << 1);
            if(13 < k) {                                        
                mv_chr->dx += 2;                                            
            } else if(2 < k) {                                  
                mv_chr->dx += 1;                                            
            }                                                       
        } else {                                                    
            k = (-dx) & 0x0f;                                   
            mv_chr->dx = (Ipp16s)(((-dx) >> 4) << 1);
            if(13 < k) {                                        
                mv_chr->dx += 2;                                            
            } else if(2 < k) {                                  
                mv_chr->dx += 1;                                            
            }                                                       
            mv_chr->dx = (Ipp16s)(-(mv_chr->dx));
        }                                                           

        if (0 == dy) {                                         
            mv_chr->dy = 0;                                             
        } else if(0 < dy) {                                     
            k = dy & 0x0f;                                  
            mv_chr->dy = (Ipp16s)((dy >> 4) << 1);
            if(13 < k) {
                mv_chr->dy += 2;
            } else if(2 < k) {
                mv_chr->dy += 1;
            }                                                       
        } else {                                                    
            k = (-dy) & 0x0f;                                   
            mv_chr->dy = (Ipp16s)(((-dy) >> 4) << 1);                     
            if(13 < k) {                                        
                mv_chr->dy += 2;                                            
            } else if(2 < k) {                                  
                mv_chr->dy += 1;                                            
            }                                                       
            mv_chr->dy = (Ipp16s)(-(mv_chr->dy));
        }                                                                       
    }   else {
        if (0 == mv_lum[0].dx) {                                           
            mv_chr->dx = 0;                                             
        } else if(0 < mv_lum[0].dx) {                                       
            mv_chr->dx = (Ipp16s)((mv_lum[0].dx >> 2) << 1);
            if(mv_lum[0].dx & 0x3) {                                        
                mv_chr->dx += 1;                                            
            }                                                       
        } else {                                                    
            mv_chr->dx = (Ipp16s)(((-mv_lum[0].dx) >> 2) << 1);
            if(mv_lum[0].dx & 0x3) {                                        
                mv_chr->dx += 1;                                            
            }                                                       
            mv_chr->dx = (Ipp16s)(-(mv_chr->dx));
        }                                                           

        if (0 == mv_lum[0].dy) {                                           
            mv_chr->dy = 0;                                             
        } else if(0 < mv_lum[0].dy) {                                       
            mv_chr->dy = (Ipp16s)((mv_lum[0].dy >> 2) << 1);
            if(mv_lum[0].dy & 0x3) {                                        
                mv_chr->dy += 1;                                            
            }                                                       
        } else {                                                    
            mv_chr->dy = (Ipp16s)(((-mv_lum[0].dy) >> 2) << 1);
            if(mv_lum[0].dy & 0x3) {                                        
                mv_chr->dy += 1;                                            
            }                                                       
            mv_chr->dy = (Ipp16s)(-(mv_chr->dy));
        }           
    }
    
    return SAMPLE_STATUS_NOERR;
}

/******************************************************************************
// Name:                expand_frame_dec_mpeg4
// Description:         expand reference rectangular VOP with one MacroBlock in
//                      size to handle unrestricted motion compensated
//                      prediction over the picture boundaries 
//
// Input Arguments: 
//          dec_state   Pointer to the general state struct of MPEG-4 decoder
// Output Arguments:    
//          dec_state   Pointer to the updated general state struct of MPEG-4
//                      decoder
// Returns:  
//      SAMPLE_STATUS_NOERR     If succeeds
******************************************************************************/
sample_status expand_frame_dec_mpeg4 (mp4_dec_state *dec_state)
{

    int y_step  = dec_state->frame_step_set.y_step;
    int cb_step = dec_state->frame_step_set.cb_step;
    int cr_step = dec_state->frame_step_set.cr_step;

    int width  = dec_state->frame_dimension.width;
    int height = dec_state->frame_dimension.height;

    Ipp8u *y_ptr  = dec_state->fwd_ref_frame.y_ptr  - SAMPLE_VIDEO_MB_SIZE
        * y_step  - SAMPLE_VIDEO_MB_SIZE;

    Ipp8u *cb_ptr = dec_state->fwd_ref_frame.cb_ptr - SAMPLE_VIDEO_BLOCK_SIZE
        * cb_step - SAMPLE_VIDEO_BLOCK_SIZE;
        
    Ipp8u *cr_ptr = dec_state->fwd_ref_frame.cr_ptr - SAMPLE_VIDEO_BLOCK_SIZE
        * cr_step - SAMPLE_VIDEO_BLOCK_SIZE;
    
    /* Padding expandY */
    /* y_ptr must be 8 byte aligned */
    ippiExpandFrame_H263_8u(y_ptr, width,height, SAMPLE_VIDEO_MB_SIZE, y_step);
    
    /* Padding expandU */
    /* cb_ptr must be 8 byte aligned */
    ippiExpandFrame_H263_8u(cb_ptr, width/2, height/2, SAMPLE_VIDEO_BLOCK_SIZE,
        cb_step);
    
    /* Padding expandV */
    /* cr_ptr must be 8 byte aligned */
    ippiExpandFrame_H263_8u(cr_ptr, width/2, height/2, SAMPLE_VIDEO_BLOCK_SIZE,
        cr_step);

    return SAMPLE_STATUS_NOERR;
}


/******************************************************************************
// Name:            set_ref_frame_dec_mpeg4
// Description:     set reference plane, namely switch between current frame
//                  and forward reference frame
//
// Input Arguments: 
//          dec_state   Pointer to the general state struct of MPEG-4 decoder
//
// Output Arguments:    
//          dec_state   Pointer to the updated state struct of MPEG-4 decoder
//
// Returns:  
//      SAMPLE_STATUS_NOERR         If succeeds
******************************************************************************/
sample_status set_ref_frame_dec_mpeg4 (mp4_dec_state *dec_state)
{
    
    sample_spacial_ptrset   tmp_frame;
    
    /* switch current and previous ref frame */
    tmp_frame = dec_state->fwd_ref_frame;
    dec_state->fwd_ref_frame = dec_state->cur_frame;
    dec_state->cur_frame = tmp_frame;
    
    return SAMPLE_STATUS_NOERR;
}


/******************************************************************************
// Name:                    search_next_sc_mpeg4
// Description:             search for next_start_code to delimit the whole 
//                          unit of the object (vop, gov, user data) and
//                          guarantee its complete residence in the buffer 
//
// Input Arguments: 
//      stream_buf          Pointer to the source video bitstream
//
//  Output Arguments:
//      result_pos          Pointer to the position of next_start_code if 
//                          it's found
//
//  Returns:    
//      SAMPLE_STATUS_NOERR             If succeeds
//      SAMPLE_STATUS_SYNCNOTFOUND_ERR  If cannot find next sync code
******************************************************************************/
sample_status search_next_sc_mpeg4
(const sample_bitstream *stream_buf, Ipp8u **result_pos)
{
    sample_bitstream stream;
    Ipp32u       code;
    int          data_len;
    
    stream.bs_cur_byte      = stream_buf->bs_cur_byte;
    stream.bs_cur_bitoffset = 0;
    data_len = stream_buf->bs_bytelen - (stream_buf->bs_cur_byte
        - stream_buf->bs_buffer);
    
    /* search for the prefix 24 bits of next_start_code */
    if (3 > data_len) {
        return SAMPLE_STATUS_SYNCNOTFOUND_ERR;
    } else {
        code = get_bits_mpeg4(&stream, 24);
        data_len -= 3;
    }

    while ((MPEG4_PREFIX_SC != code) && (0 < data_len)) {
        code = ((code << 8) | get_bits_mpeg4(&stream, 8)) & 0xFFFFFF;
        data_len -= 1;
    }
    
    if (MPEG4_PREFIX_SC != code) {
        return SAMPLE_STATUS_SYNCNOTFOUND_ERR;
    } else {
        *result_pos = stream.bs_cur_byte;
        return SAMPLE_STATUS_NOERR;
    }   
}

/***************************************************************************
// Name:                insert_sc_mpeg4
// Description:         insert sync code at the end of stream
//
// Input Arguments:
//      stream_buf  Pointer to video bitstream buffer
//
// Output Arguments:
//      stream_buf  Pointer to updated video bitstream buffer
//
// Returns:
//      None
//
*****************************************************************************/
void insert_sc_mpeg4 (sample_bitstream *stream_buf)
{
    /* video buffer was allocated extra 3 bytes to ensure it will not
    // overflow */
    stream_buf->bs_buffer[stream_buf->bs_bytelen + 0] = 0x00;
    stream_buf->bs_buffer[stream_buf->bs_bytelen + 1] = 0x00;
    stream_buf->bs_buffer[stream_buf->bs_bytelen + 2] = 0x01;

    stream_buf->bs_bytelen += 3;
}