Files
gortsplib/pkg/format/g711.go
2024-01-26 17:21:27 +01:00

135 lines
2.3 KiB
Go

package format
import (
"strconv"
"strings"
"github.com/pion/rtp"
"github.com/bluenviron/gortsplib/v4/pkg/format/rtplpcm"
)
// G711 is the RTP format for the G711 codec, encoded with mu-law or A-law.
// Specification: https://datatracker.ietf.org/doc/html/rfc3551
type G711 struct {
PayloadTyp uint8
MULaw bool
SampleRate int
ChannelCount int
}
func (f *G711) unmarshal(ctx *unmarshalContext) error {
f.PayloadTyp = ctx.payloadType
if ctx.payloadType == 0 {
f.MULaw = true
f.SampleRate = 8000
f.ChannelCount = 1
return nil
}
if ctx.payloadType == 8 {
f.MULaw = false
f.SampleRate = 8000
f.ChannelCount = 1
return nil
}
f.MULaw = (ctx.codec == "pcmu")
tmp := strings.SplitN(ctx.clock, "/", 2)
tmp1, err := strconv.ParseUint(tmp[0], 10, 31)
if err != nil {
return err
}
f.SampleRate = int(tmp1)
if len(tmp) >= 2 {
tmp1, err := strconv.ParseUint(tmp[1], 10, 31)
if err != nil {
return err
}
f.ChannelCount = int(tmp1)
} else {
f.ChannelCount = 1
}
return nil
}
// Codec implements Format.
func (f *G711) Codec() string {
return "G711"
}
// ClockRate implements Format.
func (f *G711) ClockRate() int {
return f.SampleRate
}
// PayloadType implements Format.
func (f *G711) PayloadType() uint8 {
return f.PayloadTyp
}
// RTPMap implements Format.
func (f *G711) RTPMap() string {
ret := ""
if f.MULaw {
ret += "PCMU"
} else {
ret += "PCMA"
}
ret += "/" + strconv.FormatInt(int64(f.SampleRate), 10)
if f.ChannelCount != 1 {
ret += "/" + strconv.FormatInt(int64(f.ChannelCount), 10)
}
return ret
}
// FMTP implements Format.
func (f *G711) FMTP() map[string]string {
return nil
}
// PTSEqualsDTS implements Format.
func (f *G711) PTSEqualsDTS(*rtp.Packet) bool {
return true
}
// CreateDecoder creates a decoder able to decode the content of the format.
func (f *G711) CreateDecoder() (*rtplpcm.Decoder, error) {
d := &rtplpcm.Decoder{
BitDepth: 8,
ChannelCount: f.ChannelCount,
}
err := d.Init()
if err != nil {
return nil, err
}
return d, nil
}
// CreateEncoder creates an encoder able to encode the content of the format.
func (f *G711) CreateEncoder() (*rtplpcm.Encoder, error) {
e := &rtplpcm.Encoder{
PayloadType: f.PayloadType(),
BitDepth: 8,
ChannelCount: f.ChannelCount,
}
err := e.Init()
if err != nil {
return nil, err
}
return e, nil
}