fix comment

av/av.go

@@ -1,5 +1,5 @@
 
-// Package av defines import interfaces and data structures includes container demux/mux and audio encode/decode.
+// Package av defines basic interfaces and data structures of container demux/mux and audio encode/decode.
 package av
 
 import (

av/pktque/filters.go

@@ -1,4 +1,5 @@
 
+// Package pktque provides packet Filter interface and structures used by other components.
 package pktque
 
 import (
@@ -7,9 +8,11 @@ import (
 )
 
 type Filter interface {
+	// Change packet time or drop packet
 	ModifyPacket(pkt *av.Packet, streams []av.CodecData, videoidx int, audioidx int) (drop bool, err error)
 }
 
+// Combine multiple Filters into one, ModifyPacket will be called in order.
 type Filters []Filter
 
 func (self Filters) ModifyPacket(pkt *av.Packet, streams []av.CodecData, videoidx int, audioidx int) (drop bool, err error) {
@@ -24,6 +27,7 @@ func (self Filters) ModifyPacket(pkt *av.Packet, streams []av.CodecData, videoid
 	return
 }
 
+// Wrap origin Demuxer and Filter into a new Demuxer, when read this Demuxer filters will be called.
 type FilterDemuxer struct {
 	av.Demuxer
 	Filter Filter
@@ -62,6 +66,7 @@ func (self FilterDemuxer) ReadPacket() (pkt av.Packet, err error) {
 	return
 }
 
+// Drop packets until first video key frame arrived.
 type WaitKeyFrame struct {
 	ok bool
 }
@@ -74,12 +79,13 @@ func (self *WaitKeyFrame) ModifyPacket(pkt *av.Packet, streams []av.CodecData, v
 	return
 }
 
+// Fix incorrect packet timestamps.
 type FixTime struct {
 	zerobase time.Duration
 	incrbase time.Duration
 	lasttime time.Duration
-	StartFromZero bool
-	MakeIncrement bool
+	StartFromZero bool // make timestamp start from zero
+	MakeIncrement bool // force timestamp increment
 }
 
 func (self *FixTime) ModifyPacket(pkt *av.Packet, streams []av.CodecData, videoidx int, audioidx int) (drop bool, err error) {
@@ -105,6 +111,7 @@ func (self *FixTime) ModifyPacket(pkt *av.Packet, streams []av.CodecData, videoi
 	return
 }
 
+// Drop incorrect packets to make A/V sync.
 type AVSync struct {
 	MaxTimeDiff time.Duration
 	time []time.Duration
@@ -163,6 +170,7 @@ func (self *AVSync) check(i int) (start time.Duration, end time.Duration, correc
 	return
 }
 
+// Make packets reading speed as same as walltime, effect like ffmpeg -re option.
 type Walltime struct {
 	firsttime time.Time
 }

av/pubsub/queue.go

@@ -1,3 +1,5 @@
+
+// Packege pubsub implements publisher-subscribers model used in multi-channel streaming.
 package pubsub
 
 import (
@@ -17,6 +19,7 @@ import (
 // oldest          latest
 // 
 
+// One publisher and multiple subscribers thread-safe packet queue buffer.
 type Queue struct {
 	pkts []av.Packet
 	head, tail int
@@ -43,6 +46,7 @@ func NewQueue(streams []av.CodecData) *Queue {
 	return q
 }
 
+// Set max buffered total packets duration.
 func (self *Queue) SetMaxDuration(dur time.Duration) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -55,6 +59,7 @@ func (self *Queue) SetMaxDuration(dur time.Duration) {
 	return
 }
 
+// Currently buffered packets total duration.
 func (self *Queue) Duration() (dur time.Duration) {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
@@ -65,6 +70,7 @@ func (self *Queue) Duration() (dur time.Duration) {
 	return
 }
 
+// After Close() called, all QueueCursor's ReadPacket will return io.EOF.
 func (self *Queue) Close() (err error) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -74,6 +80,7 @@ func (self *Queue) Close() (err error) {
 	return
 }
 
+// Put packet into buffer, old packets will be discared.
 func (self *Queue) WritePacket(pkt av.Packet) (err error) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -101,6 +108,7 @@ func (self *Queue) newCursor() *QueueCursor {
 	}
 }
 
+// Create cursor position at latest packet.
 func (self *Queue) Latest() *QueueCursor {
 	cursor := self.newCursor()
 	cursor.init = func(pkts []av.Packet, videoidx int) int {
@@ -109,6 +117,7 @@ func (self *Queue) Latest() *QueueCursor {
 	return cursor
 }
 
+// Create cursor position at oldest buffered packet.
 func (self *Queue) Oldest() *QueueCursor {
 	cursor := self.newCursor()
 	cursor.init = func(pkts []av.Packet, videoidx int) int {
@@ -117,6 +126,7 @@ func (self *Queue) Oldest() *QueueCursor {
 	return cursor
 }
 
+// Create cursor position at specific time in buffered packets.
 func (self *Queue) DelayedTime(dur time.Duration) *QueueCursor {
 	cursor := self.newCursor()
 	cursor.init = func(pkts []av.Packet, videoidx int) int {
@@ -134,6 +144,7 @@ func (self *Queue) DelayedTime(dur time.Duration) *QueueCursor {
 	return cursor
 }
 
+// Create cursor position at specific delayed GOP count in buffered packets.
 func (self *Queue) DelayedGopCount(n int) *QueueCursor {
 	cursor := self.newCursor()
 	cursor.init = func(pkts []av.Packet, videoidx int) int {
@@ -159,6 +170,7 @@ func (self *QueueCursor) Streams() (streams []av.CodecData, err error) {
 	return
 }
 
+// ReadPacket will not consume packets in Queue, it's just a cursor.
 func (self *QueueCursor) ReadPacket() (pkt av.Packet, err error) {
 	self.que.cond.L.Lock()
 	if self.pos == -1 {

av/transcode/transcode.go

@@ -1,3 +1,5 @@
+
+// Package transcoder implements Transcoder based on Muxer/Demuxer and AudioEncoder/AudioDecoder interface.
 package transcode
 
 import (