av/rtmp/rtmp.go

269 lines
6.5 KiB
Go

/*
NAME
rtmp.go
DESCRIPTION
See Readme.md
AUTHOR
Saxon Nelson-Milton <saxon@ausocean.org>
Dan Kortschak <dan@ausocean.org>
LICENSE
rtmp.go is Copyright (C) 2017 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
*/
package rtmp
/*
#cgo CFLAGS: -I/usr/local/include/librtmp
#cgo LDFLAGS: -lrtmp -Wl,-rpath=/usr/local/lib
#include <stdlib.h>
#include <string.h>
#include <rtmp.h>
RTMP* start_session(RTMP* rtmp, char* url, uint connect_timeout);
int write_frame(RTMP* rtmp, char* data, uint data_length);
int end_session(RTMP* rtmp);
*/
import "C"
import (
"errors"
"log"
"strconv"
"unsafe"
_"fmt"
"math"
)
const (
minDataSize = 11
)
// Session provides an interface for sending flv tags over rtmp.
type Session interface {
Open() error
Write([]byte) (int, error)
Close() error
}
// session provides parameters required for an rtmp communication session.
type session struct {
rtmp *C.RTMP
url string
timeout uint
}
var _ Session = (*session)(nil)
// NewSession returns a new session.
func NewSession(url string, connectTimeout uint) Session {
return &session{
url: url,
timeout: connectTimeout,
}
}
// C.AVal is in amf.h
// See #define AVC(str) {str, sizeof(str)-1} in amf.h
func AVC(str string) C.AVal {
var aval C.AVal
aval.av_val = C.CString(str)
aval.av_len = C.int(len(str))
return aval
}
// av_setDataFrame is a static const global in rtmp.c
var setDataFrame = AVC("@setDataFrame")
// Open establishes an rtmp connection with the url passed into the
// constructor
func (s *session) Open() error {
if s.rtmp != nil {
return errors.New("rtmp: attempt to start already running session")
}
var err error
s.rtmp, err = C.start_session(s.rtmp, C.CString(s.url), C.uint(s.timeout))
if s.rtmp == nil {
return err
}
return nil
}
// Write writes a frame (flv tag) to the rtmp connection
func (s *session) Write(data []byte) (int, error) {
if s.rtmp == nil {
return 0, Err(3)
}
if C.RTMP_IsConnected(s.rtmp) <= 0 {
return 0, Err(1)
}
if C.RTMP_Write(s.rtmp,(*C.char)(unsafe.Pointer(&data[0])),C.int(len(data))) <= 0 {
//if rtmpWrite(s.rtmp, data) <= 0 {
return 0, Err(2)
}
return len(data), nil
}
const (
RTMP_PACKET_SIZE_LARGE = 0
RTMP_PACKET_SIZE_MEDIUM = 1
RTMP_PACKET_SIZE_SMALL = 2
RTMP_PACKET_TYPE_INFO = 0x12
RTMP_PACKET_TYPE_AUDIO = 0x08
RTMP_PACKET_TYPE_VIDEO = 0x09
)
func rtmpWrite(r *C.RTMP, data []byte) int {
buf := (*C.char)(unsafe.Pointer(&data[0]))
var pkt = &r.m_write
var pend, enc *C.char
size := len(data)
s2 := size
var ret, num int
pkt.m_nChannel = 0x04
pkt.m_nInfoField2 = r.m_stream_id
for s2 > 0 || s2 < 0{
if pkt.m_nBytesRead == 0 {
if size < minDataSize {
log.Printf("size: %d\n", size)
log.Printf("too small \n")
return 0
}
buf0 := *(*byte)(unsafe.Pointer(buf))
buf1 := *(*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(1)))
buf2 := *(*byte)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(2)))
if buf0 == 'F' && buf1 == 'L' && buf2 == 'V' {
buf = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(13)))
s2 -= 13
}
pkt.m_packetType = C.uchar(*(*byte)(unsafe.Pointer(buf)))
buf = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(1)))
pkt.m_nBodySize = C.AMF_DecodeInt24(buf)
buf = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(3)))
pkt.m_nTimeStamp = C.AMF_DecodeInt24(buf)
buf = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(3)))
pkt.m_nTimeStamp |= C.uint(*((*byte)(unsafe.Pointer(buf)))) << 24
buf = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(4)))
s2 -= 11
if ((pkt.m_packetType == RTMP_PACKET_TYPE_AUDIO ||
pkt.m_packetType == RTMP_PACKET_TYPE_VIDEO) &&
pkt.m_nTimeStamp == 0) || pkt.m_packetType == RTMP_PACKET_TYPE_INFO {
pkt.m_headerType = RTMP_PACKET_SIZE_LARGE
if pkt.m_packetType == RTMP_PACKET_TYPE_INFO {
pkt.m_nBodySize += 16
}
} else {
pkt.m_headerType = RTMP_PACKET_SIZE_MEDIUM
}
if int(C.RTMPPacket_Alloc(pkt, pkt.m_nBodySize)) == 0 {
log.Println("Failed to allocate packet")
return 0
}
enc = pkt.m_body
pend = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(enc)) +
uintptr(pkt.m_nBodySize)))
if pkt.m_packetType == RTMP_PACKET_TYPE_INFO {
enc = C.AMF_EncodeString(enc, pend, &setDataFrame)
pkt.m_nBytesRead = C.uint(math.Abs(float64(uintptr(unsafe.Pointer(enc)) -
uintptr(unsafe.Pointer(pkt.m_body)))))
}
} else {
enc = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(pkt.m_body)) +
uintptr(pkt.m_nBytesRead)))
}
num = int(pkt.m_nBodySize - pkt.m_nBytesRead)
if num > s2 {
num = s2
}
for i := 0; i < num; i++ {
*(*byte)(unsafe.Pointer(enc)) = *(*byte)(unsafe.Pointer(buf))
}
//C.memcpy(unsafe.Pointer(enc),unsafe.Pointer(buf),C.ulong(num))
pkt.m_nBytesRead += C.uint(num)
s2 -= num
buf = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(num)))
if pkt.m_nBytesRead == pkt.m_nBodySize {
ret = int(C.RTMP_SendPacket(r, pkt, 0))
C.RTMPPacket_Free(pkt)
pkt.m_nBytesRead = 0
if ret == 0 {
return -1
}
buf = (*C.char)(unsafe.Pointer(uintptr(unsafe.Pointer(buf)) + uintptr(4)))
s2 -= 4
if s2 < 0 {
break
}
}
}
return size + s2
}
/*
func sendPacket(r *C.RTMP, pkt *C.RTMPPacket, queue int) int {
const prevPacket *C.RTMPPacket
last := 0
var nSize, hSize, cSize int
var
}
*/
// Close terminates the rtmp connection
func (s *session) Close() error {
if s.rtmp == nil {
return Err(3)
}
ret := C.end_session(s.rtmp)
s.rtmp = nil
if ret != 0 {
return Err(ret)
}
return nil
}
var rtmpErrs = [...]string{
1: "rtmp: not connected",
2: "rtmp: write error",
3: "rtmp: not started",
}
type Err uint
func (e Err) Error() string {
if 0 <= int(e) && int(e) < len(rtmpErrs) {
s := rtmpErrs[e]
if s != "" {
return s
}
}
return "rtmp: " + strconv.Itoa(int(e))
}
func byteSliceToCArr(buf []byte) *C.char {
return (*C.char)(unsafe.Pointer(&buf[0]))
}