mpegvideo.c

手机端的H264源码

/*
 * The simplest mpeg encoder (well, it was the simplest!)
 * Copyright (c) 2000,2001 Fabrice Bellard.
 * Copyright (c) 2002-2004 Michael Niedermayer <[e-mail]>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * 4MV & hq & b-frame encoding stuff by Michael Niedermayer <[e-mail]>
 */
 
/**
 * @file mpegvideo.c
 * The simplest mpeg encoder (well, it was the simplest!).
 */ 
 
#include <limits.h>
#include <math.h> //for PI
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"


#ifdef USE_FASTMEMCPY
#include "fastmemcpy.h"
#endif

#include <assert.h>

static void draw_edges_c(uint8_t *buf, int wrap, int width, int height, int w);

void (*draw_edges)(uint8_t *buf, int wrap, int width, int height, int w)= draw_edges_c;

/* enable all paranoid tests for rounding, overflows, etc... */
//#define PARANOID

//#define DEBUG


/* for jpeg fast DCT */
#define CONST_BITS 14

static const uint16_t aanscales[64] = {
    /* precomputed values scaled up by 14 bits */
    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
    22725, 31521, 29692, 26722, 22725, 17855, 12299,  6270,
    21407, 29692, 27969, 25172, 21407, 16819, 11585,  5906,
    19266, 26722, 25172, 22654, 19266, 15137, 10426,  5315,
    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
    12873, 17855, 16819, 15137, 12873, 10114,  6967,  3552,
    8867 , 12299, 11585, 10426,  8867,  6967,  4799,  2446,
    4520 ,  6270,  5906,  5315,  4520,  3552,  2446,  1247
};

static const uint8_t h263_chroma_roundtab[16] = {
//  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
    0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2,
};

static const uint8_t ff_default_chroma_qscale_table[32]={
//  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
};


void ff_init_scantable(uint8_t *permutation, ScanTable *st, const uint8_t *src_scantable){
    int i;
    int end;
    
    st->scantable= src_scantable;

    for(i=0; i<64; i++){
        int j;
        j = src_scantable[i];
        st->permutated[i] = permutation[j];
#ifdef ARCH_POWERPC
        st->inverse[j] = i;
#endif
    }
    
    end=-1;
    for(i=0; i<64; i++){
        int j;
        j = st->permutated[i];
        if(j>end) end=j;
        st->raster_end[i]= end;
    }
}

/* init common dct for both encoder and decoder */
int DCT_common_init(MpegEncContext *s)
{    

#ifdef CONFIG_ENCODERS
    s->dct_quantize= dct_quantize_c;
    s->denoise_dct= denoise_dct_c;
#endif
        
#ifdef HAVE_MMX
    MPV_common_init_mmx(s);
#endif
#ifdef ARCH_ALPHA
    MPV_common_init_axp(s);
#endif
#ifdef HAVE_MLIB
    MPV_common_init_mlib(s);
#endif
#ifdef HAVE_MMI
    MPV_common_init_mmi(s);
#endif
#ifdef ARCH_ARMV4L
    MPV_common_init_armv4l(s);
#endif
#ifdef ARCH_POWERPC
    MPV_common_init_ppc(s);
#endif

#ifdef CONFIG_ENCODERS
    s->fast_dct_quantize= s->dct_quantize;

    if(s->flags&CODEC_FLAG_TRELLIS_QUANT){
        s->dct_quantize= dct_quantize_trellis_c; //move before MPV_common_init_*
    }

#endif //CONFIG_ENCODERS

    /* load & permutate scantables
       note: only wmv uses differnt ones 
    */
    if(s->alternate_scan){
        ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
        ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
    }else{
        ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
        ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
    }
    ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
    ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);

    return 0;
}

static void copy_picture(Picture *dst, Picture *src){
    *dst = *src;
    dst->type= FF_BUFFER_TYPE_COPY;
}

/**
 * allocates a Picture
 * The pixels are allocated/set by calling get_buffer() if shared=0
 */
static int alloc_picture(MpegEncContext *s, Picture *pic, int shared){
    const int big_mb_num= s->mb_stride*(s->mb_height+1) + 1; //the +1 is needed so memset(,,stride*height) doesnt sig11
    const int mb_array_size= s->mb_stride*s->mb_height;
    const int b8_array_size= s->b8_stride*s->mb_height*2;
    const int b4_array_size= s->b4_stride*s->mb_height*4;
    int i;
    
    if(shared){
#ifndef WINCE //assert
        assert(pic->data[0]);
        assert(pic->type == 0 || pic->type == FF_BUFFER_TYPE_SHARED);
#endif
        pic->type= FF_BUFFER_TYPE_SHARED;
    }else{
        int r;
#ifndef WINCE //assert
        assert(!pic->data[0]);
#endif
        r= s->avctx->get_buffer(s->avctx, (AVFrame*)pic);
        
        if(r<0 || !pic->age || !pic->type || !pic->data[0]){
	    //av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed (%d %d %d %p)\n", r, pic->age, pic->type, pic->data[0]);
            return -1;
        }

        if(s->linesize && (s->linesize != pic->linesize[0] || s->uvlinesize != pic->linesize[1])){
            //av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed (stride changed)\n");
            return -1;
        }

        if(pic->linesize[1] != pic->linesize[2]){
            //av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed (uv stride missmatch)\n");
            return -1;
        }

        s->linesize  = pic->linesize[0];
        s->uvlinesize= pic->linesize[1];
    }
    
    if(pic->qscale_table==NULL){
        
        CHECKED_ALLOCZ(pic->mbskip_table , mb_array_size * sizeof(uint8_t)+2) //the +2 is for the slice end check
        CHECKED_ALLOCZ(pic->qscale_table , mb_array_size * sizeof(uint8_t))
        CHECKED_ALLOCZ(pic->mb_type_base , big_mb_num    * sizeof(uint32_t))
        pic->mb_type= pic->mb_type_base + s->mb_stride+1;
        if(s->out_format == FMT_H264){
            for(i=0; i<2; i++){
                CHECKED_ALLOCZ(pic->motion_val_base[i], 2 * (b4_array_size+2)  * sizeof(int16_t))
                pic->motion_val[i]= pic->motion_val_base[i]+2;
                CHECKED_ALLOCZ(pic->ref_index[i] , b8_array_size * sizeof(uint8_t))
            }
            pic->motion_subsample_log2= 2;
        }
        
        pic->qstride= s->mb_stride;
        //CHECKED_ALLOCZ(pic->pan_scan , 1 * sizeof(AVPanScan))
    }

    //it might be nicer if the application would keep track of these but it would require a API change
    memmove(s->prev_pict_types+1, s->prev_pict_types, PREV_PICT_TYPES_BUFFER_SIZE-1);
    s->prev_pict_types[0]= s->pict_type;
    if(pic->age < PREV_PICT_TYPES_BUFFER_SIZE && s->prev_pict_types[pic->age] == B_TYPE)
        pic->age= INT_MAX; // skiped MBs in b frames are quite rare in mpeg1/2 and its a bit tricky to skip them anyway
    
    return 0;
fail: //for the CHECKED_ALLOCZ macro
    return -1;
}

/**
 * deallocates a picture
 */
static void free_picture(MpegEncContext *s, Picture *pic)
{	
    int i;

	//DEBUGMSG(1,(L"free_picture\n"));

    if(pic->data[0] && pic->type!=FF_BUFFER_TYPE_SHARED)
	{
        s->avctx->release_buffer(s->avctx, (AVFrame*)pic);
    }
    
    av_freep(&pic->mbskip_table);
    av_freep(&pic->qscale_table);
    av_freep(&pic->mb_type_base);
    //av_freep(&pic->pan_scan);
    pic->mb_type= NULL;
    for(i=0; i<2; i++)
	{
        av_freep(&pic->motion_val_base[i]);
        av_freep(&pic->ref_index[i]);
    }
    
    if(pic->type == FF_BUFFER_TYPE_SHARED)
	{
        for(i=0; i<4; i++)
		{
            pic->base[i]=
            pic->data[i]= NULL;
        }
        pic->type= 0;        
    }
}

static int init_duplicate_context(MpegEncContext *s, MpegEncContext *base){
    int i;

    // edge emu needs blocksize + filter length - 1 (=17x17 for halfpel / 21x21 for h264) 
    CHECKED_ALLOCZ(s->allocated_edge_emu_buffer, (s->width+64)*2*17*2); //(width + edge + align)*interlaced*MBsize*tolerance
    s->edge_emu_buffer= s->allocated_edge_emu_buffer + (s->width+64)*2*17;

    CHECKED_ALLOCZ(s->blocks, 64*12*2 * sizeof(DCTELEM))
    s->block= s->blocks[0];

    for(i=0;i<12;i++){
        s->pblocks[i] = (short *)(&s->block[i]);
    }
    return 0;
fail:
    return -1; //free() through MPV_common_end()
}

static void free_duplicate_context(MpegEncContext *s){
    if(s==NULL) return;

    av_freep(&s->allocated_edge_emu_buffer); s->edge_emu_buffer= NULL;
        
    //av_freep(&s->dct_error_sum);
    av_freep(&s->blocks);
    s->block= NULL;
}



/**
 * sets the given MpegEncContext to common defaults (same for encoding and decoding).
 * the changed fields will not depend upon the prior state of the MpegEncContext.
 */
static void MPV_common_defaults(MpegEncContext *s){
    //s->y_dc_scale_table=
    //s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
    s->progressive_frame= 1;
    s->progressive_sequence= 1;
    s->picture_structure= PICT_FRAME;

    s->coded_picture_number = 0;
    s->picture_number = 0;
    s->input_picture_number = 0;

    s->picture_in_gop_number = 0;

}

/**
 * sets the given MpegEncContext to defaults for decoding.
 * the changed fields will not depend upon the prior state of the MpegEncContext.
 */
void MPV_decode_defaults(MpegEncContext *s){
    MPV_common_defaults(s);
}

void MPV_common_end(MpegEncContext *s)
{
	int i, j, k;

	free_duplicate_context(s);
	
	av_freep(&s->parse_context.buffer);
	s->parse_context.buffer_size=0;	
	
	av_freep(&s->mbintra_table);
	av_freep(&s->cbp_table);

	av_freep(&s->mbskip_table);
	av_freep(&s->prev_pict_types);
	av_freep(&s->mb_index2xy);
	//av_freep(&s->dct_offset);

	if(s->picture)
	{
		for(i=0; i<MAX_PICTURE_COUNT; i++)
		{
			free_picture(s, &s->picture[i]);
		}
	}

	av_freep(&s->picture);

	avcodec_default_free_buffers(s->avctx);
	s->context_initialized = 0;
	s->last_picture_ptr= NULL;
	s->next_picture_ptr= NULL;
	s->current_picture_ptr= NULL;

}

/** 
 * init common structure for both encoder and decoder.
 * this assumes that some variables like width/height are already set
 */
int MPV_common_init(MpegEncContext *s)
{
    int y_size, c_size, yc_size, i, mb_array_size, mv_table_size, x, y;

    dsputil_init(&s->dsp, s->avctx);
    DCT_common_init(s);

    s->flags= s->avctx->flags;
    s->flags2= s->avctx->flags2;

    s->mb_width  = (s->width  + 15) / 16;
    s->mb_height = (s->height + 15) / 16;
    s->mb_stride = s->mb_width + 1;
    s->b8_stride = s->mb_width*2 + 1;
    s->b4_stride = s->mb_width*4 + 1;
    mb_array_size= s->mb_height * s->mb_stride;
    mv_table_size= (s->mb_height+2) * s->mb_stride + 1;

    /* set default edge pos, will be overriden in decode_header if needed */
    s->h_edge_pos= s->mb_width*16;
    s->v_edge_pos= s->mb_height*16;

    s->mb_num = s->mb_width * s->mb_height;
    
    s->block_wrap[0]=
    s->block_wrap[1]=
    s->block_wrap[2]=
    s->block_wrap[3]= s->b8_stride;
    s->block_wrap[4]=
    s->block_wrap[5]= s->mb_stride;
 
    y_size = s->b8_stride * (2 * s->mb_height + 1);
    c_size = s->mb_stride * (s->mb_height + 1);
    yc_size = y_size + 2 * c_size;