utils.c

float av_int2flt(int32_t v){
    if(v+v > 0xFF000000U)
        return 0.0/0.0;
    return ldexp(((v&0x7FFFFF) + (1<<23)) * (v>>31|1), (v>>23&0xFF)-150);
}

int64_t av_dbl2int(double d){
    int e;
    if     ( !d) return 0;
    else if(d-d) return 0x7FF0000000000000LL + ((int64_t)(d<0)<<63) + (d!=d);
    d= frexp(d, &e);
    return (int64_t)(d<0)<<63 | (e+1022LL)<<52 | (int64_t)((fabs(d)-0.5)*(1LL<<53));
}

int32_t av_flt2int(float d){
    int e;
    if     ( !d) return 0;
    else if(d-d) return 0x7F800000 + ((d<0)<<31) + (d!=d);
    d= frexp(d, &e);
    return (d<0)<<31 | (e+126)<<23 | (int64_t)((fabs(d)-0.5)*(1<<24));
}

/* av_log API */

static int av_log_level = AV_LOG_INFO;

static void av_log_default_callback(void* ptr, int level, const char* fmt, va_list vl)
{
    static int print_prefix=1;
    AVClass* avc= ptr ? *(AVClass**)ptr : NULL;
    if(level>av_log_level)
	return;
#undef fprintf
    if(print_prefix && avc) {
	    fprintf(stderr, "[%s @ %p]", avc->item_name(ptr), avc);
    }
#define fprintf please_use_av_log
        
    print_prefix= strstr(fmt, "\n") != NULL;
        
    vfprintf(stderr, fmt, vl);
}

static void (*av_log_callback)(void*, int, const char*, va_list) = av_log_default_callback;

void av_log(void* avcl, int level, const char *fmt, ...)
{
    va_list vl;
    va_start(vl, fmt);
    av_vlog(avcl, level, fmt, vl);
    va_end(vl);
}

void av_vlog(void* avcl, int level, const char *fmt, va_list vl)
{
    av_log_callback(avcl, level, fmt, vl);
}

int av_log_get_level(void)
{
    return av_log_level;
}

void av_log_set_level(int level)
{
    av_log_level = level;
}

void av_log_set_callback(void (*callback)(void*, int, const char*, va_list))
{
    av_log_callback = callback;
}

#if !defined(HAVE_THREADS)
int avcodec_thread_init(AVCodecContext *s, int thread_count){
    return -1;
}
#endif

unsigned int av_xiphlacing(unsigned char *s, unsigned int v)
{
    unsigned int n = 0;

    while(v >= 0xff) {
        *s++ = 0xff;
        v -= 0xff;
        n++;
    }
    *s = v;
    n++;
    return n;
}