int align= (-(int)(buf))&3;
int align= (-(size_t)(buf))&3;
static void escape_FF(MpegEncContext *s, int start){    int size= get_bit_count(&s->pb) - start*8;    int i, ff_count;    uint8_t *buf= s->pb.buf + start;    int align= (-(int)(buf))&3;        assert((size&7) == 0);    size >>= 3;        ff_count=0;    for(i=0; i<size && i<align; i++){        if(buf[i]==0xFF) ff_count++;    }    for(; i<size-15; i+=16){        int acc, v;        v= *(uint32_t*)(&buf[i]);        acc= (((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;        v= *(uint32_t*)(&buf[i+4]);        acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;        v= *(uint32_t*)(&buf[i+8]);        acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;        v= *(uint32_t*)(&buf[i+12]);        acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;        acc>>=4;        acc+= (acc>>16);        acc+= (acc>>8);        ff_count+= acc&0xFF;    }    for(; i<size; i++){        if(buf[i]==0xFF) ff_count++;    }    if(ff_count==0) return;        /* skip put bits */    for(i=0; i<ff_count-3; i+=4)        put_bits(&s->pb, 32, 0);    put_bits(&s->pb, (ff_count-i)*8, 0);    flush_put_bits(&s->pb);     for(i=size-1; ff_count; i--){        int v= buf[i];        if(v==0xFF){//printf("%d %d\n", i, ff_count);            buf[i+ff_count]= 0;            ff_count--;        }        buf[i+ff_count]= v;    }}