From af5022af6257334bfaeb724752732b8083bb4449 Mon Sep 17 00:00:00 2001
From: zyxar <chou.marcus@gmail.com>
Date: Wed, 19 Aug 2015 11:51:00 +0800
Subject: [PATCH] seperate fifo with tta header

---
 decoder.go | 23 +++++++++++++++++++-
 encoder.go | 40 ++++++++++++++++++++++++++++++++++-
 fifo.go    | 61 ------------------------------------------------------
 3 files changed, 61 insertions(+), 63 deletions(-)

diff --git a/decoder.go b/decoder.go
index 9ca6f16..55d80fd 100644
--- a/decoder.go
+++ b/decoder.go
@@ -290,6 +290,27 @@ func (this *Decoder) SetInfo(info *tta_info) error {
 	return nil
 }
 
+func (this *Decoder) ReadHeader(info *tta_info) (uint32, error) {
+	size := this.fifo.skip_id3v2()
+	this.fifo.reset()
+	if 'T' != this.fifo.read_byte() ||
+		'T' != this.fifo.read_byte() ||
+		'A' != this.fifo.read_byte() ||
+		'1' != this.fifo.read_byte() {
+		return 0, TTA_FORMAT_ERROR
+	}
+	info.format = uint32(this.fifo.read_uint16())
+	info.nch = uint32(this.fifo.read_uint16())
+	info.bps = uint32(this.fifo.read_uint16())
+	info.sps = this.fifo.read_uint32()
+	info.samples = this.fifo.read_uint32()
+	if !this.fifo.read_crc32() {
+		return 0, TTA_FILE_ERROR
+	}
+	size += 22
+	return size, nil
+}
+
 func (this *Decoder) GetInfo(info *tta_info, pos int64) (err error) {
 	if pos != 0 {
 		if _, err = this.fifo.io.Seek(pos, os.SEEK_SET); err != nil {
@@ -299,7 +320,7 @@ func (this *Decoder) GetInfo(info *tta_info, pos int64) (err error) {
 	}
 	this.fifo.read_start()
 	var p uint32
-	if p, err = this.fifo.read_tta_header(info); err != nil {
+	if p, err = this.ReadHeader(info); err != nil {
 		return
 	}
 	if info.format > 2 ||
diff --git a/encoder.go b/encoder.go
index d19f7fc..d5dff7b 100644
--- a/encoder.go
+++ b/encoder.go
@@ -250,6 +250,44 @@ func (this *Encoder) frame_reset(frame uint32, iocb io.ReadWriteSeeker) {
 	this.frame_init(frame)
 }
 
+func (this *Encoder) WriteHeader(info *tta_info) (size uint32, err error) {
+	this.fifo.reset()
+	// write TTA1 signature
+	if err = this.fifo.write_byte('T'); err != nil {
+		return
+	}
+	if err = this.fifo.write_byte('T'); err != nil {
+		return
+	}
+	if err = this.fifo.write_byte('A'); err != nil {
+		return
+	}
+	if err = this.fifo.write_byte('1'); err != nil {
+		return
+	}
+	if err = this.fifo.write_uint16(uint16(info.format)); err != nil {
+		return
+	}
+	if err = this.fifo.write_uint16(uint16(info.nch)); err != nil {
+		return
+	}
+	if err = this.fifo.write_uint16(uint16(info.bps)); err != nil {
+		return
+	}
+	if err = this.fifo.write_uint32(info.sps); err != nil {
+		return
+	}
+	if err = this.fifo.write_uint32(info.samples); err != nil {
+		return
+	}
+	if err = this.fifo.write_crc32(); err != nil {
+		return
+	}
+	size = 22
+	return
+
+}
+
 func (this *Encoder) SetInfo(info *tta_info, pos int64) (err error) {
 	if info.format > 2 ||
 		info.bps < MIN_BPS ||
@@ -266,7 +304,7 @@ func (this *Encoder) SetInfo(info *tta_info, pos int64) (err error) {
 	}
 	this.fifo.write_start()
 	var p uint32
-	if p, err = this.fifo.write_tta_header(info); err != nil {
+	if p, err = this.WriteHeader(info); err != nil {
 		return
 	}
 	this.offset = uint64(pos) + uint64(p)
diff --git a/fifo.go b/fifo.go
index a6a886d..5ac7951 100644
--- a/fifo.go
+++ b/fifo.go
@@ -71,27 +71,6 @@ func (s *tta_fifo) skip_id3v2() (size uint32) {
 	return
 }
 
-func (s *tta_fifo) read_tta_header(info *tta_info) (uint32, error) {
-	size := s.skip_id3v2()
-	s.reset()
-	if 'T' != s.read_byte() ||
-		'T' != s.read_byte() ||
-		'A' != s.read_byte() ||
-		'1' != s.read_byte() {
-		return 0, TTA_FORMAT_ERROR
-	}
-	info.format = uint32(s.read_uint16())
-	info.nch = uint32(s.read_uint16())
-	info.bps = uint32(s.read_uint16())
-	info.sps = s.read_uint32()
-	info.samples = s.read_uint32()
-	if !s.read_crc32() {
-		return 0, TTA_FILE_ERROR
-	}
-	size += 22
-	return size, nil
-}
-
 func (s *tta_fifo) get_value(rice *tta_adapt) (value int32) {
 	if s.bcache^bit_mask[s.bcount] == 0 {
 		value += int32(s.bcount)
@@ -221,46 +200,6 @@ func (s *tta_fifo) write_skip_bytes(size uint32) error {
 	return nil
 }
 
-func (s *tta_fifo) write_tta_header(info *tta_info) (size uint32, err error) {
-	s.reset()
-
-	// write TTA1 signature
-	if err = s.write_byte('T'); err != nil {
-		return
-	}
-	if err = s.write_byte('T'); err != nil {
-		return
-	}
-	if err = s.write_byte('A'); err != nil {
-		return
-	}
-	if err = s.write_byte('1'); err != nil {
-		return
-	}
-
-	if err = s.write_uint16(uint16(info.format)); err != nil {
-		return
-	}
-	if err = s.write_uint16(uint16(info.nch)); err != nil {
-		return
-	}
-	if err = s.write_uint16(uint16(info.bps)); err != nil {
-		return
-	}
-	if err = s.write_uint32(info.sps); err != nil {
-		return
-	}
-	if err = s.write_uint32(info.samples); err != nil {
-		return
-	}
-
-	if err = s.write_crc32(); err != nil {
-		return
-	}
-	size = 22
-	return
-}
-
 func (s *tta_fifo) put_value(rice *tta_adapt, value int32) {
 	var k, unary, outval uint32
 	if value > 0 {