v4l.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

#include "i386/mmx.h"

#define LINE_WITH_UV \
                    movq_m2r(ptr[0],mm0); \
                    movq_m2r(ptr[8],mm1);  \
                    movq_r2r(mm0, mm4); \
                    punpcklbw_r2r(mm1,mm0); \
                    punpckhbw_r2r(mm1,mm4); \
                    movq_r2r(mm0,mm5); \
                    punpcklbw_r2r(mm4,mm0); \
                    punpckhbw_r2r(mm4,mm5); \
                    movq_r2r(mm0,mm1); \
                    punpcklbw_r2r(mm5,mm1); \
                    movq_r2m(mm1,lum[0]); \
                    movq_m2r(ptr[16],mm2); \
                    movq_m2r(ptr[24],mm1); \
                    movq_r2r(mm2,mm4); \
                    punpcklbw_r2r(mm1,mm2); \
                    punpckhbw_r2r(mm1,mm4); \
                    movq_r2r(mm2,mm3); \
                    punpcklbw_r2r(mm4,mm2); \
                    punpckhbw_r2r(mm4,mm3); \
                    movq_r2r(mm2,mm1); \
                    punpcklbw_r2r(mm3,mm1); \
                    movq_r2m(mm1,lum[8]); \
                    punpckhdq_r2r(mm2,mm0); \
                    punpckhdq_r2r(mm3,mm5); \
                    movq_r2m(mm0,cb[0]); \
                    movq_r2m(mm5,cr[0]);

#define LINE_NO_UV \
                    movq_m2r(ptr[0],mm0);\
                    movq_m2r(ptr[8],mm1);\
                    movq_r2r(mm0, mm4);\
                    punpcklbw_r2r(mm1,mm0); \
                    punpckhbw_r2r(mm1,mm4);\
                    movq_r2r(mm0,mm5);\
                    punpcklbw_r2r(mm4,mm0);\
                    punpckhbw_r2r(mm4,mm5);\
                    movq_r2r(mm0,mm1);\
                    punpcklbw_r2r(mm5,mm1);\
                    movq_r2m(mm1,lum[0]);\
                    movq_m2r(ptr[16],mm2);\
                    movq_m2r(ptr[24],mm1);\
                    movq_r2r(mm2,mm4);\
                    punpcklbw_r2r(mm1,mm2);\
                    punpckhbw_r2r(mm1,mm4);\
                    movq_r2r(mm2,mm3);\
                    punpcklbw_r2r(mm4,mm2);\
                    punpckhbw_r2r(mm4,mm3);\
                    movq_r2r(mm2,mm1);\
                    punpcklbw_r2r(mm3,mm1);\
                    movq_r2m(mm1,lum[8]);

#define LINE_WITHUV_AVG \
                    movq_m2r(ptr[0], mm0);\
                    movq_m2r(ptr[8], mm1);\
                    movq_r2r(mm0, mm4);\
                    punpcklbw_r2r(mm1,mm0);\
                    punpckhbw_r2r(mm1,mm4);\
                    movq_r2r(mm0,mm5);\
                    punpcklbw_r2r(mm4,mm0);\
                    punpckhbw_r2r(mm4,mm5);\
                    movq_r2r(mm0,mm1);\
                    movq_r2r(mm5,mm2);\
                    punpcklbw_r2r(mm7,mm1);\
                    punpcklbw_r2r(mm7,mm2);\
                    paddw_r2r(mm6,mm1);\
                    paddw_r2r(mm2,mm1);\
                    psraw_i2r(1,mm1);\
                    packuswb_r2r(mm7,mm1);\
                    movd_r2m(mm1,lum[0]);\
                    movq_m2r(ptr[16],mm2);\
                    movq_m2r(ptr[24],mm1);\
                    movq_r2r(mm2,mm4);\
                    punpcklbw_r2r(mm1,mm2);\
                    punpckhbw_r2r(mm1,mm4);\
                    movq_r2r(mm2,mm3);\
                    punpcklbw_r2r(mm4,mm2);\
                    punpckhbw_r2r(mm4,mm3);\
                    movq_r2r(mm2,mm1);\
                    movq_r2r(mm3,mm4);\
                    punpcklbw_r2r(mm7,mm1);\
                    punpcklbw_r2r(mm7,mm4);\
                    paddw_r2r(mm6,mm1);\
                    paddw_r2r(mm4,mm1);\
                    psraw_i2r(1,mm1);\
                    packuswb_r2r(mm7,mm1);\
                    movd_r2m(mm1,lum[4]);\
                    punpckhbw_r2r(mm7,mm0);\
                    punpckhbw_r2r(mm7,mm2);\
                    paddw_r2r(mm6,mm0);\
                    paddw_r2r(mm2,mm0);\
                    psraw_i2r(1,mm0);\
                    packuswb_r2r(mm7,mm0);\
                    punpckhbw_r2r(mm7,mm5);\
                    punpckhbw_r2r(mm7,mm3);\
                    paddw_r2r(mm6,mm5);\
                    paddw_r2r(mm3,mm5);\
                    psraw_i2r(1,mm5);\
                    packuswb_r2r(mm7,mm5);\
                    movd_r2m(mm0,cb[0]);\
                    movd_r2m(mm5,cr[0]);

#define LINE_NOUV_AVG \
                    movq_m2r(ptr[0],mm0);\
                    movq_m2r(ptr[8],mm1);\
                    pand_r2r(mm5,mm0);\
                    pand_r2r(mm5,mm1);\
                    pmaddwd_r2r(mm6,mm0);\
                    pmaddwd_r2r(mm6,mm1);\
                    packssdw_r2r(mm1,mm0);\
                    paddw_r2r(mm6,mm0);\
                    psraw_i2r(1,mm0);\
                    movq_m2r(ptr[16],mm2);\
                    movq_m2r(ptr[24],mm3);\
                    pand_r2r(mm5,mm2);\
                    pand_r2r(mm5,mm3);\
                    pmaddwd_r2r(mm6,mm2);\
                    pmaddwd_r2r(mm6,mm3);\
                    packssdw_r2r(mm3,mm2);\
                    paddw_r2r(mm6,mm2);\
                    psraw_i2r(1,mm2);\
                    packuswb_r2r(mm2,mm0);\
                    movq_r2m(mm0,lum[0]);

#define DEINT_LINE_LUM(ptroff) \
                    movd_m2r(lum_m4[(ptroff)],mm0);\
                    movd_m2r(lum_m3[(ptroff)],mm1);\
                    movd_m2r(lum_m2[(ptroff)],mm2);\
                    movd_m2r(lum_m1[(ptroff)],mm3);\
                    movd_m2r(lum[(ptroff)],mm4);\
                    punpcklbw_r2r(mm7,mm0);\
                    movd_r2m(mm2,lum_m4[(ptroff)]);\
                    punpcklbw_r2r(mm7,mm1);\
                    punpcklbw_r2r(mm7,mm2);\
                    punpcklbw_r2r(mm7,mm3);\
                    punpcklbw_r2r(mm7,mm4);\
                    psllw_i2r(2,mm1);\
                    psllw_i2r(1,mm2);\
                    paddw_r2r(mm6,mm1);\
                    psllw_i2r(2,mm3);\
                    paddw_r2r(mm2,mm1);\
                    paddw_r2r(mm4,mm0);\
                    paddw_r2r(mm3,mm1);\
                    psubusw_r2r(mm0,mm1);\
                    psrlw_i2r(3,mm1);\
                    packuswb_r2r(mm7,mm1);\
                    movd_r2m(mm1,lum_m2[(ptroff)]);

#else
#include "dsputil.h"

#define LINE_WITH_UV \
                    lum[0]=ptr[0];lum[1]=ptr[2];lum[2]=ptr[4];lum[3]=ptr[6];\
                    cb[0]=ptr[1];cb[1]=ptr[5];\
                    cr[0]=ptr[3];cr[1]=ptr[7];\
                    lum[4]=ptr[8];lum[5]=ptr[10];lum[6]=ptr[12];lum[7]=ptr[14];\
                    cb[2]=ptr[9];cb[3]=ptr[13];\
                    cr[2]=ptr[11];cr[3]=ptr[15];\
                    lum[8]=ptr[16];lum[9]=ptr[18];lum[10]=ptr[20];lum[11]=ptr[22];\
                    cb[4]=ptr[17];cb[5]=ptr[21];\
                    cr[4]=ptr[19];cr[5]=ptr[23];\
                    lum[12]=ptr[24];lum[13]=ptr[26];lum[14]=ptr[28];lum[15]=ptr[30];\
                    cb[6]=ptr[25];cb[7]=ptr[29];\
                    cr[6]=ptr[27];cr[7]=ptr[31];

#define LINE_NO_UV \
                    lum[0]=ptr[0];lum[1]=ptr[2];lum[2]=ptr[4];lum[3]=ptr[6];\
                    lum[4]=ptr[8];lum[5]=ptr[10];lum[6]=ptr[12];lum[7]=ptr[14];\
                    lum[8]=ptr[16];lum[9]=ptr[18];lum[10]=ptr[20];lum[11]=ptr[22];\
                    lum[12]=ptr[24];lum[13]=ptr[26];lum[14]=ptr[28];lum[15]=ptr[30];

#define LINE_WITHUV_AVG \
                    sum=(ptr[0]+ptr[2]+1) >> 1;lum[0]=sum; \
                    sum=(ptr[4]+ptr[6]+1) >> 1;lum[1]=sum; \
                    sum=(ptr[1]+ptr[5]+1) >> 1;cb[0]=sum; \
                    sum=(ptr[3]+ptr[7]+1) >> 1;cr[0]=sum; \
                    sum=(ptr[8]+ptr[10]+1) >> 1;lum[2]=sum; \
                    sum=(ptr[12]+ptr[14]+1) >> 1;lum[3]=sum; \
                    sum=(ptr[9]+ptr[13]+1) >> 1;cb[1]=sum; \
                    sum=(ptr[11]+ptr[15]+1) >> 1;cr[1]=sum; \
                    sum=(ptr[16]+ptr[18]+1) >> 1;lum[4]=sum; \
                    sum=(ptr[20]+ptr[22]+1) >> 1;lum[5]=sum; \
                    sum=(ptr[17]+ptr[21]+1) >> 1;cb[2]=sum; \
                    sum=(ptr[19]+ptr[23]+1) >> 1;cr[2]=sum; \
                    sum=(ptr[24]+ptr[26]+1) >> 1;lum[6]=sum; \
                    sum=(ptr[28]+ptr[30]+1) >> 1;lum[7]=sum; \
                    sum=(ptr[25]+ptr[29]+1) >> 1;cb[3]=sum; \
                    sum=(ptr[27]+ptr[31]+1) >> 1;cr[3]=sum;

#define LINE_NOUV_AVG \
                    sum=(ptr[0]+ptr[2]+1) >> 1;lum[0]=sum; \
                    sum=(ptr[4]+ptr[6]+1) >> 1;lum[1]=sum; \
                    sum=(ptr[8]+ptr[10]+1) >> 1;lum[2]=sum; \
                    sum=(ptr[12]+ptr[14]+1) >> 1;lum[3]=sum; \
                    sum=(ptr[16]+ptr[18]+1) >> 1;lum[4]=sum; \
                    sum=(ptr[20]+ptr[22]+1) >> 1;lum[5]=sum; \
                    sum=(ptr[24]+ptr[26]+1) >> 1;lum[6]=sum; \
                    sum=(ptr[28]+ptr[30]+1) >> 1;lum[7]=sum;

#define DEINT_LINE_LUM(ptroff) \
                    sum=(-lum_m4[(ptroff)]+(lum_m3[(ptroff)]<<2)+(lum_m2[(ptroff)]<<1)+(lum_m1[(ptroff)]<<2)-lum[(ptroff)]); \
                    lum_m4[(ptroff)]=lum_m2[(ptroff)];\
                    lum_m2[(ptroff)]=cm[(sum+4)>>3];\
                    sum=(-lum_m4[(ptroff)+1]+(lum_m3[(ptroff)+1]<<2)+(lum_m2[(ptroff)+1]<<1)+(lum_m1[(ptroff)+1]<<2)-lum[(ptroff)+1]); \
                    lum_m4[(ptroff)+1]=lum_m2[(ptroff)+1];\
                    lum_m2[(ptroff)+1]=cm[(sum+4)>>3];\
                    sum=(-lum_m4[(ptroff)+2]+(lum_m3[(ptroff)+2]<<2)+(lum_m2[(ptroff)+2]<<1)+(lum_m1[(ptroff)+2]<<2)-lum[(ptroff)+2]); \
                    lum_m4[(ptroff)+2]=lum_m2[(ptroff)+2];\
                    lum_m2[(ptroff)+2]=cm[(sum+4)>>3];\
                    sum=(-lum_m4[(ptroff)+3]+(lum_m3[(ptroff)+3]<<2)+(lum_m2[(ptroff)+3]<<1)+(lum_m1[(ptroff)+3]<<2)-lum[(ptroff)+3]); \
                    lum_m4[(ptroff)+3]=lum_m2[(ptroff)+3];\
                    lum_m2[(ptroff)+3]=cm[(sum+4)>>3];

#endif


/* Read two fields separately. */
static int aiw_read_picture(VideoData *s, uint8_t *data)
{
    uint8_t *ptr, *lum, *cb, *cr;
    int h;
#ifndef HAVE_MMX
    int sum;
#endif
    uint8_t* src = s->src_mem;
    uint8_t *ptrend = &src[s->width*2];
    lum=data;
    cb=&lum[s->width*s->height];
    cr=&cb[(s->width*s->height)/4];
    if (s->deint == 0 && s->halfw == 0) {
        while (read(s->fd,src,s->width*2) < 0) {
            usleep(100);
        }
        for (h = 0; h < s->height-2; h+=2) {
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16, cb+=8, cr+=8) {
                LINE_WITH_UV
                    }
            read(s->fd,src,s->width*2);
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16) {
                LINE_NO_UV
                    }
            read(s->fd,src,s->width*2);
        }
        /*
         * Do last two lines
         */
        for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16, cb+=8, cr+=8) {
            LINE_WITH_UV
                }
        read(s->fd,src,s->width*2);
        for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16) {
            LINE_NO_UV
                }
        /* drop second field */
        while (read(s->fd,src,s->width*2) < 0) {
            usleep(100);
        }
        for (h = 0; h < s->height - 1; h++) {
            read(s->fd,src,s->width*2);
        }
    } else if (s->halfw == 1) {
#ifdef HAVE_MMX
        mmx_t rounder;
        mmx_t masker;
        rounder.uw[0]=1;
        rounder.uw[1]=1;
        rounder.uw[2]=1;
        rounder.uw[3]=1;
        masker.ub[0]=0xff;
        masker.ub[1]=0;
        masker.ub[2]=0xff;
        masker.ub[3]=0;
        masker.ub[4]=0xff;
        masker.ub[5]=0;
        masker.ub[6]=0xff;
        masker.ub[7]=0;
        pxor_r2r(mm7,mm7);
        movq_m2r(rounder,mm6);
#endif
        while (read(s->fd,src,s->width*4) < 0) {
            usleep(100);
        }
        ptrend = &src[s->width*4];
        for (h = 0; h < s->height-2; h+=2) {
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=8, cb+=4, cr+=4) {
                LINE_WITHUV_AVG
                    }
            read(s->fd,src,s->width*4);
#ifdef HAVE_MMX
            movq_m2r(masker,mm5);
#endif
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=8) {
                LINE_NOUV_AVG
                    }
            read(s->fd,src,s->width*4);
        }
        /*
 * Do last two lines
 */
        for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=8, cb+=4, cr+=4) {
            LINE_WITHUV_AVG
                }
        read(s->fd,src,s->width*4);
#ifdef HAVE_MMX
        movq_m2r(masker,mm5);
#endif
        for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=8) {
            LINE_NOUV_AVG
                }
        /* drop second field */
        while (read(s->fd,src,s->width*4) < 0) {
            usleep(100);
        }
        for (h = 0; h < s->height - 1; h++) {
            read(s->fd,src,s->width*4);
        }
    } else {
        uint8_t *lum_m1, *lum_m2, *lum_m3, *lum_m4;
#ifdef HAVE_MMX
        mmx_t rounder;
        rounder.uw[0]=4;
        rounder.uw[1]=4;
        rounder.uw[2]=4;
        rounder.uw[3]=4;
        movq_m2r(rounder,mm6);
        pxor_r2r(mm7,mm7);
#else
        uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
#endif

        /* read two fields and deinterlace them */
        while (read(s->fd,src,s->width*2) < 0) {
            usleep(100);
        }
        for (h = 0; h < (s->height/2)-2; h+=2) {
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16, cb+=8, cr+=8) {
                LINE_WITH_UV
                    }
            read(s->fd,src,s->width*2);
            /* skip a luminance line - will be filled in later */
            lum += s->width;
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16, cb+=8, cr+=8) {
                LINE_WITH_UV
                    }
            /* skip a luminance line - will be filled in later */
            lum += s->width;
            read(s->fd,src,s->width*2);
        }
        /*
 * Do last two lines
 */
        for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16, cb+=8, cr+=8) {
            LINE_WITH_UV
                }
        /* skip a luminance line - will be filled in later */
        lum += s->width;
        read(s->fd,src,s->width*2);
        for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16, cb+=8, cr+=8) {
            LINE_WITH_UV
                }
        /*
 *
 * SECOND FIELD
 *
 */
        lum=&data[s->width];
        while (read(s->fd,src,s->width*2) < 0) {
            usleep(10);
        }
        /* First (and last) two lines not interlaced */
        for (h = 0; h < 2; h++) {
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16) {
                LINE_NO_UV
                    }
            read(s->fd,src,s->width*2);
            /* skip a luminance line */
            lum += s->width;
        }
        lum_m1=&lum[-s->width];
        lum_m2=&lum_m1[-s->width];
        lum_m3=&lum_m2[-s->width];
        memmove(s->lum_m4_mem,&lum_m3[-s->width],s->width);
        for (; h < (s->height/2)-1; h++) {
            lum_m4=s->lum_m4_mem;
            for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16,lum_m1+=16,lum_m2+=16,lum_m3+=16,lum_m4+=16) {
                LINE_NO_UV

                    DEINT_LINE_LUM(0)
                    DEINT_LINE_LUM(4)
                    DEINT_LINE_LUM(8)
                    DEINT_LINE_LUM(12)
                    }
            read(s->fd,src,s->width*2);
            /* skip a luminance line */
            lum += s->width;
            lum_m1 += s->width;
            lum_m2 += s->width;
            lum_m3 += s->width;
            //                lum_m4 += s->width;
        }
        /*
 * Do last line
 */
        lum_m4=s->lum_m4_mem;
        for (ptr = &src[0]; ptr < ptrend; ptr+=32, lum+=16, lum_m1+=16, lum_m2+=16, lum_m3+=16, lum_m4+=16) {
            LINE_NO_UV

                DEINT_LINE_LUM(0)
                DEINT_LINE_LUM(4)
                DEINT_LINE_LUM(8)
                DEINT_LINE_LUM(12)
                }
    }
    emms_c();
    return s->frame_size;
}

static int aiw_close(VideoData *s)
{
    av_freep(&s->lum_m4_mem);
    av_freep(&s->src_mem);
    return 0;
}