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sampler.go
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/
sampler.go
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package mediadevices
import (
"math"
"time"
)
type samplerFunc func() uint32
// newVideoSampler creates a video sampler that uses the actual video frame rate and
// the codec's clock rate to come up with a duration for each sample.
func newVideoSampler(clockRate uint32) samplerFunc {
clockRateFloat := float64(clockRate)
lastTimestamp := time.Now()
return samplerFunc(func() uint32 {
now := time.Now()
duration := now.Sub(lastTimestamp).Seconds()
samples := uint32(math.Round(clockRateFloat * duration))
lastTimestamp = now
return samples
})
}
// newAudioSampler creates a audio sampler that uses a fixed latency and
// the codec's clock rate to come up with a duration for each sample.
func newAudioSampler(clockRate uint32, latency time.Duration) samplerFunc {
samples := uint32(math.Round(float64(clockRate) * latency.Seconds()))
return samplerFunc(func() uint32 {
return samples
})
}