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da47189fc3
Squash integration of the reviewed Go core, frontend audit fixes, release tooling, and deployment hygiene. CI passed all Server/Client jobs.
71 lines
1.9 KiB
Go
71 lines
1.9 KiB
Go
package nativecapture
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import (
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"encoding/binary"
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"errors"
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"io"
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"time"
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)
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const (
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envelopeHeaderBytes = 28
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maxMediaBytes = 1024 * 1024
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maxStatusBytes = 4 * 1024
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)
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type FrameKind uint8
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const (
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FramePCM FrameKind = 1
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FrameH264 FrameKind = 2
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FrameStatus FrameKind = 3
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FrameVP8 FrameKind = 4
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)
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type Frame struct {
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Kind FrameKind
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KeyFrame bool
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Timestamp time.Duration
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Duration time.Duration
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Data []byte
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}
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func readFrame(input io.Reader) (Frame, error) {
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header := make([]byte, envelopeHeaderBytes)
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if _, err := io.ReadFull(input, header); err != nil {
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return Frame{}, err
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}
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kind := FrameKind(header[5])
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size := binary.BigEndian.Uint32(header[24:])
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maximum := uint32(maxMediaBytes)
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if kind == FrameStatus {
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maximum = maxStatusBytes
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}
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if string(header[:4]) != "SMED" || header[4] != 1 || header[7] != 0 ||
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(kind != FramePCM && kind != FrameH264 && kind != FrameVP8 && kind != FrameStatus) ||
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size == 0 || size > maximum {
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return Frame{}, errors.New("native capture frame header is invalid")
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}
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timestamp100ns := binary.BigEndian.Uint64(header[8:16])
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duration100ns := binary.BigEndian.Uint64(header[16:24])
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if kind == FrameStatus {
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if header[6] != 0 || timestamp100ns != 0 || duration100ns != 0 {
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return Frame{}, errors.New("native capture status frame is invalid")
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}
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} else if duration100ns == 0 || (kind == FramePCM && header[6] != 0) ||
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((kind == FrameH264 || kind == FrameVP8) && header[6] > 1) {
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return Frame{}, errors.New("native capture media frame is invalid")
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}
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data := make([]byte, size)
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if _, err := io.ReadFull(input, data); err != nil {
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return Frame{}, err
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}
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return Frame{
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Kind: kind,
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KeyFrame: (kind == FrameH264 || kind == FrameVP8) && header[6] == 1,
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Timestamp: time.Duration(timestamp100ns) * 100 * time.Nanosecond,
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Duration: time.Duration(duration100ns) * 100 * time.Nanosecond,
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Data: data,
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}, nil
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}
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