refactor(oto): reuse temp buffers for repeated calls to convert buffer

This commit is contained in:
vsariola 2020-12-31 16:24:34 +02:00
parent 1d91603e36
commit c68d9d3bf5
3 changed files with 21 additions and 27 deletions

View File

@ -1,29 +1,25 @@
package oto
import (
"bytes"
"encoding/binary"
"fmt"
"math"
)
// FloatBufferTo16BitLE is a naive helper method to convert []float32 buffers to
// 16-bit little-endian integer buffers.
// TODO: optimize/refactor this, current is far from the best solution
func FloatBufferTo16BitLE(buff []float32) ([]byte, error) {
var buf bytes.Buffer
for i, v := range buff {
// 16-bit little-endian, but encoded in byte buffer
//
// Appends the encoded bytes into "to" slice, allowing you to preallocate the
// capacity or just use nil
func FloatBufferTo16BitLE(from []float32, to []byte) []byte {
for _, v := range from {
var uv int16
if v < -1.0 {
uv = -math.MaxInt16
uv = -math.MaxInt16 // we are a bit lazy: -1.0 is encoded as -32767, as this makes math easier, and -32768 is unused
} else if v > 1.0 {
uv = math.MaxInt16
} else {
uv = int16(v * math.MaxInt16)
}
if err := binary.Write(&buf, binary.LittleEndian, uv); err != nil {
return nil, fmt.Errorf("error converting buffer (@ %v, value %v) to bytes: %w", i, v, err)
}
to = append(to, byte(uv&255), byte(uv>>8))
}
return buf.Bytes(), nil
return to
}

View File

@ -10,10 +10,7 @@ import (
func TestFloatBufferToBytes(t *testing.T) {
floats := []float32{0, 0.000489128, 0, 0.0019555532, 0, 0.0043964, 0, 0.007806882, 0, 0.012180306, 0, 0.017508084, 0, 0.023779746, 0, 0.030982954, 0, 0.039103523, 0, 0.04812544, 0, 0.05803088, 0, 0.068800256, 0, 0.08041221, 0, 0.09284368, 0, 0.10606992, 0, 0.120064534, 0, 0.13479951, 0, 0.1502453, 0, 0.16637078, 0, 0.18314338, 0, 0.20052913, 0, 0.21849263, 0, 0.23699719, 0, 0.2560048, 0, 0.27547634, 0, 0.29537144, 0, 0.31564865, 0, 0.33626547, 0, 0.35717854, 0, 0.37834346, 0, 0.39971504, 0, 0.4212474, 0, 0.4428938, 0, 0.46460703, 0, 0.48633927, 0, 0.50804216, 0, 0.52966696, 0, 0.5511646, 0, 0.57248586, 0, 0.5935812, 0, 0.6144009, 0, 0.63489544, 0, 0.6550152, 0, 0.67471063, 0, 0.6939326, 0, 0.712632, 0, 0.7307603, 0, 0.7482692, 0, 0.7651111, 0, 0.7812389}
bytes := []byte{0x0, 0x0, 0x10, 0x0, 0x0, 0x0, 0x40, 0x0, 0x0, 0x0, 0x90, 0x0, 0x0, 0x0, 0xff, 0x0, 0x0, 0x0, 0x8f, 0x1, 0x0, 0x0, 0x3d, 0x2, 0x0, 0x0, 0xb, 0x3, 0x0, 0x0, 0xf7, 0x3, 0x0, 0x0, 0x1, 0x5, 0x0, 0x0, 0x28, 0x6, 0x0, 0x0, 0x6d, 0x7, 0x0, 0x0, 0xce, 0x8, 0x0, 0x0, 0x4a, 0xa, 0x0, 0x0, 0xe2, 0xb, 0x0, 0x0, 0x93, 0xd, 0x0, 0x0, 0x5e, 0xf, 0x0, 0x0, 0x40, 0x11, 0x0, 0x0, 0x3b, 0x13, 0x0, 0x0, 0x4b, 0x15, 0x0, 0x0, 0x71, 0x17, 0x0, 0x0, 0xaa, 0x19, 0x0, 0x0, 0xf7, 0x1b, 0x0, 0x0, 0x55, 0x1e, 0x0, 0x0, 0xc4, 0x20, 0x0, 0x0, 0x42, 0x23, 0x0, 0x0, 0xce, 0x25, 0x0, 0x0, 0x66, 0x28, 0x0, 0x0, 0xa, 0x2b, 0x0, 0x0, 0xb7, 0x2d, 0x0, 0x0, 0x6d, 0x30, 0x0, 0x0, 0x29, 0x33, 0x0, 0x0, 0xeb, 0x35, 0x0, 0x0, 0xb0, 0x38, 0x0, 0x0, 0x77, 0x3b, 0x0, 0x0, 0x3f, 0x3e, 0x0, 0x0, 0x7, 0x41, 0x0, 0x0, 0xcb, 0x43, 0x0, 0x0, 0x8c, 0x46, 0x0, 0x0, 0x46, 0x49, 0x0, 0x0, 0xf9, 0x4b, 0x0, 0x0, 0xa4, 0x4e, 0x0, 0x0, 0x43, 0x51, 0x0, 0x0, 0xd6, 0x53, 0x0, 0x0, 0x5c, 0x56, 0x0, 0x0, 0xd2, 0x58, 0x0, 0x0, 0x36, 0x5b, 0x0, 0x0, 0x88, 0x5d, 0x0, 0x0, 0xc6, 0x5f, 0x0, 0x0, 0xee, 0x61, 0x0, 0x0, 0xfe, 0x63}
converted, err := oto.FloatBufferTo16BitLE(floats)
if err != nil {
t.Fatalf("FloatBufferTo16BitLE threw an error")
}
converted := oto.FloatBufferTo16BitLE(floats, nil)
for i, v := range converted {
if bytes[i] != v {
t.Fail()
@ -34,10 +31,7 @@ func TestFloatBufferToBytesLimits(t *testing.T) {
0xDE, 0x7F, // float 0.999 = 0x7FDE = 0111111111011110
0x22, 0x80, // float -0.999 = 0x8022 = 1000000000100010
}
converted, err := oto.FloatBufferTo16BitLE(floats)
if err != nil {
t.Fatalf("FloatBufferTo16BitLE threw an error")
}
converted := oto.FloatBufferTo16BitLE(floats, nil)
for i, v := range converted {
if bytes[i] != v {
t.Fail()

View File

@ -8,10 +8,13 @@ import (
)
type OtoContext oto.Context
type OtoOutput oto.Player
type OtoOutput struct {
player *oto.Player
tmpBuffer []byte
}
func (c *OtoContext) Output() sointu.AudioSink {
return (*OtoOutput)((*oto.Context)(c).NewPlayer())
return &OtoOutput{player: (*oto.Context)(c).NewPlayer(), tmpBuffer: make([]byte, 0)}
}
const otoBufferSize = 8192
@ -34,9 +37,10 @@ func (c *OtoContext) Close() error {
// Play implements the audio.Player interface for OtoPlayer
func (o *OtoOutput) WriteAudio(floatBuffer []float32) (err error) {
if byteBuffer, err := FloatBufferTo16BitLE(floatBuffer); err != nil {
return fmt.Errorf("cannot convert buffer to bytes: %w", err)
} else if _, err := (*oto.Player)(o).Write(byteBuffer); err != nil {
// we reuse the old capacity tmpBuffer by setting its length to zero. then,
// we save the tmpBuffer so we can reuse it next time
o.tmpBuffer = FloatBufferTo16BitLE(floatBuffer, o.tmpBuffer[:0])
if _, err := o.player.Write(o.tmpBuffer); err != nil {
return fmt.Errorf("cannot write to player: %w", err)
}
return nil
@ -44,7 +48,7 @@ func (o *OtoOutput) WriteAudio(floatBuffer []float32) (err error) {
// Close disposes of resources
func (o *OtoOutput) Close() error {
if err := (*oto.Player)(o).Close(); err != nil {
if err := o.player.Close(); err != nil {
return fmt.Errorf("cannot close oto player: %w", err)
}
return nil