Files
engine/avformat/flv.go
2021-01-11 23:08:15 +08:00

114 lines
2.6 KiB
Go

package avformat
import (
"io"
"github.com/Monibuca/engine/v3/pool"
"github.com/Monibuca/engine/v3/util"
)
const (
// FLV Tag Type
FLV_TAG_TYPE_AUDIO = 0x08
FLV_TAG_TYPE_VIDEO = 0x09
FLV_TAG_TYPE_SCRIPT = 0x12
)
var (
// 音频格式. 4 bit
SoundFormat = map[byte]string{
0: "Linear PCM, platform endian",
1: "ADPCM",
2: "MP3",
3: "Linear PCM, little endian",
4: "Nellymoser 16kHz mono",
5: "Nellymoser 8kHz mono",
6: "Nellymoser",
7: "G.711 A-law logarithmic PCM",
8: "G.711 mu-law logarithmic PCM",
9: "reserved",
10: "AAC",
11: "Speex",
14: "MP3 8Khz",
15: "Device-specific sound"}
// 采样频率. 2 bit
SoundRate = map[byte]int{
0: 5500,
1: 11000,
2: 22000,
3: 44000}
// 量化精度. 1 bit
SoundSize = map[byte]string{
0: "8Bit",
1: "16Bit"}
// 音频类型. 1bit
SoundType = map[byte]string{
0: "Mono",
1: "Stereo"}
// 视频帧类型. 4bit
FrameType = map[byte]string{
1: "keyframe (for AVC, a seekable frame)",
2: "inter frame (for AVC, a non-seekable frame)",
3: "disposable inter frame (H.263 only)",
4: "generated keyframe (reserved for server use only)",
5: "video info/command frame"}
// 视频编码类型. 4bit
CodecID = map[byte]string{
1: "JPEG (currently unused)",
2: "Sorenson H.263",
3: "Screen video",
4: "On2 VP6",
5: "On2 VP6 with alpha channel",
6: "Screen video version 2",
7: "AVC",
12: "H265"}
)
var FLVHeader = []byte{0x46, 0x4c, 0x56, 0x01, 0x05, 0, 0, 0, 9, 0, 0, 0, 0}
func WriteFLVTag(w io.Writer, tag *SendPacket) (err error) {
head := pool.GetSlice(11)
defer pool.RecycleSlice(head)
tail := pool.GetSlice(4)
defer pool.RecycleSlice(tail)
head[0] = tag.Type
dataSize := uint32(len(tag.Payload))
util.BigEndian.PutUint32(tail, dataSize+11)
util.BigEndian.PutUint24(head[1:], dataSize)
util.BigEndian.PutUint24(head[4:], tag.Timestamp)
util.BigEndian.PutUint32(head[7:], 0)
if _, err = w.Write(head); err != nil {
return
}
// Tag Data
if _, err = w.Write(tag.Payload); err != nil {
return
}
if _, err = w.Write(tail); err != nil { // PreviousTagSizeN(4)
return
}
return
}
func ReadFLVTag(r io.Reader) (t byte, timestamp uint32, payload []byte, err error) {
head := pool.GetSlice(11)
defer pool.RecycleSlice(head)
if _, err = io.ReadFull(r, head); err != nil {
return
}
t = head[0]
dataSize := util.BigEndian.Uint24(head[1:])
timestamp = util.BigEndian.Uint24(head[4:])
payload = make([]byte, int(dataSize))
if _, err = io.ReadFull(r, payload); err == nil {
t := pool.GetSlice(4)
_, err = io.ReadFull(r, t)
pool.RecycleSlice(t)
}
return
}