petere
10fa72b228
Stream a synthetic test pattern and silent PCM audio over the OBS Teleport protocol: - protocol: wire format (Header/ImageHeader/WaveHeader), BT.709 full range colour matrix, JPEG encode via turbojpeg cgo, WAVE packet builder - output: TCP sender with per-connection buffered channels and drop-on-overflow - discovery: multicast announce via peerdiscovery - cmd: teleportfling CLI with flags, test-pattern frame generator Verified end-to-end: OBS discovers and renders the stream with correct colours and motion.
81 lines
2.0 KiB
Go
81 lines
2.0 KiB
Go
// Package protocol implements the obs-teleport wire format.
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//
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// This file builds the audio ("WAVE") side of the protocol: Header +
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// WaveHeader + raw interleaved PCM, byte-for-byte compatible with the
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// reference implementation (GPL-2.0).
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package protocol
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// BuildWavePacket assembles a complete ""WAVE"" wire packet:
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// Header + WaveHeader + interleaved PCM payload.
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//
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// pcm is already interleaved (L,R,L,R,… for stereo). format must be one of
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// the AudioFormat* constants. frames is the PCM frame count (samples per
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// channel). The returned slice is a freshly allocated buffer safe to hand to
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// the network.
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func BuildWavePacket(timestamp uint64, format int32, sampleRate, speakers, frames int32, pcm []byte) ([]byte, error) {
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expected := int64(speakers) * int64(frames) * int64(bytesPerSample(format))
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if int64(len(pcm)) != expected {
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return nil, errBadPCMLength{got: len(pcm), want: int(expected)}
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}
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h := Header{
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Type: AudioType,
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Timestamp: timestamp,
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Size: int32(len(pcm)),
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}
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wave := WaveHeader{
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Format: format,
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SampleRate: sampleRate,
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Speakers: speakers,
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Frames: frames,
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}
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return WritePacket(h, nil, &wave, pcm)
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}
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// bytesPerSample maps an AudioFormat* value to its size in bytes.
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func bytesPerSample(format int32) int {
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switch format {
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case AudioFormatU8:
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return 1
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case AudioFormatS16:
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return 2
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case AudioFormatS32, AudioFormatF32:
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return 4
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default:
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return 0
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}
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}
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// errBadPCMLength is returned when pcm length does not match the declared
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// format/speakers/frames.
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type errBadPCMLength struct{ got, want int }
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func (e errBadPCMLength) Error() string {
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return "protocol: pcm length mismatch" +
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": got " + itoa(e.got) + " bytes, want " + itoa(e.want)
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}
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// itoa is a tiny local int→string helper to avoid importing strconv in the
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// hot path callers.
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func itoa(v int) string {
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if v == 0 {
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return "0"
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}
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neg := v < 0
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if neg {
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v = -v
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}
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var buf [20]byte
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i := len(buf)
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for v > 0 {
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i--
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buf[i] = byte('0' + v%10)
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v /= 10
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}
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if neg {
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i--
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buf[i] = '-'
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}
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return string(buf[i:])
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}
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