本文來源于網頁設計愛好者web開發社區http://www.html.org.cn收集整理，歡迎訪問。關鍵字: vb.net directx 9 directsound 錄音 riff文件格式 作者:董含君
下午看了微軟提供的例子,居然把錄音定位成beginner級別
暈哦,雖說我認為這個例子是微軟提供的最”直接”的例子,但是步驟超多.而且還牽扯到多線程開辟緩沖區回調riff文件格式 io 輸出等等.由于錄音的復雜性,以及微軟這個例子的直接性,堅持原創的我最終還是復制了大量的代碼.(希望不要罵我....)
ok,先來說錄音的步驟,里面牽扯到riff或者使用技巧的地方,有注釋.我僅僅說步驟.附帶截圖一張
首先需要說明與往常不同的概念
1 聲卡(或者windows)把音頻設備分成2個部分,一個是錄音設備(capture),另一個是回放設備(playback)
2 前面我們用的是device創建回放設備,這次需要使用capture創建錄音設備,錄音設備不像回放,設備的能力往往很關鍵(回放雖說也很關鍵,但是設備能力基本上差別不大),所以不能單單使用一個默認就行,需要用戶指定,甚至用枚舉的辦法逐個測試性能(看看是否支持這種格式)
3 利用 dim caplist as new capturedevicescollection
得到list之后
dim info as deviceinformation
'''先得到可以使用的信息
''' 設備信息由這個集合提供
for each info in caplist
listbox1.items.add(info.description)
next
枚舉出所有設備
4 創建capture的時候,需要指定使用那個設備了,(回放的時候也可以指定,但是我們用的是默認的)
'利用選擇的設備
cap = new capture(caplist(listbox1.selectedindex).driverguid)
5 嘗試所有支持的類型
就是一個for 循環里面嵌套下面的try語句
try
cap=new capture(....)
catch
'''''失敗的時候繼續嘗試下一個
end try
6 完成設備的準備工作之后,directsound初始化完成
7 錄音,
第一步創建riff(理解成riff即可)
第二步創建錄音用的緩沖區(包括文件緩沖區以及capturebuffer)
第三步創建新的線程用于捕獲數據
8 停止
停止capture
講緩沖區內容寫入磁盤
修改riff的文件信息
釋放資源
9 播放,利用最簡單的辦法播放文件
大體步驟就這些,錄音的時候函數之間的關系比較復雜.但是沒有更簡單的辦法.
注釋比較詳細,關于riff的文件操作方法內部也有注釋.或者直接復制到你的程序直接用也行.
以下是源代碼
imports microsoft.directx.directsound
imports system.io
imports system.threading
public class form1
inherits system.windows.forms.form
private structure formatinfo
public format as waveformat
public overrides function tostring() as string
return convertwaveformattostring(format)
end function 'tostring
end structure 'formatinfo
dim devplay as new device
dim bufplay as secondarybuffer
dim formats as new arraylist
dim cap as capture
dim caplist as new capturedevicescollection
private inputformatsupported(19) as boolean
public inputformat as waveformat
private wavefile as filestream = nothing
private writer as binarywriter = nothing
public applicationnotify as notify = nothing
public applicationbuffer as capturebuffer = nothing
public notifysize as integer = 0
private notifythread as thread = nothing
public notificationevent as autoresetevent = nothing
public positionnotify(numberrecordnotifications) as bufferpositionnotify
public const numberrecordnotifications as integer = 16
public capturebuffersize as integer = 0
public nextcaptureoffset as integer = 0
private samplecount as integer = 0
#region " windows 窗體設計器生成的代碼 "
public sub new()
mybase.new()
'該調用是 windows 窗體設計器所必需的。
initializecomponent()
'在 initializecomponent() 調用之后添加任何初始化
end sub
'窗體重寫 dispose 以清理組件列表。
protected overloads overrides sub dispose(byval disposing as boolean)
if disposing then
if not (components is nothing) then
components.dispose()
end if
end if
mybase.dispose(disposing)
end sub
'windows 窗體設計器所必需的
private components as system.componentmodel.icontainer
'注意: 以下過程是 windows 窗體設計器所必需的
'可以使用 windows 窗體設計器修改此過程。
'不要使用代碼編輯器修改它。
friend withevents listbox1 as system.windows.forms.listbox
friend withevents listbox2 as system.windows.forms.listbox
friend withevents textbox1 as system.windows.forms.textbox
friend withevents button1 as system.windows.forms.button
friend withevents button2 as system.windows.forms.button
friend withevents button3 as system.windows.forms.button
friend withevents button4 as system.windows.forms.button
friend withevents label1 as system.windows.forms.label
<system.diagnostics.debuggerstepthrough()> private sub initializecomponent()
me.listbox1 = new system.windows.forms.listbox
me.listbox2 = new system.windows.forms.listbox
me.textbox1 = new system.windows.forms.textbox
me.button1 = new system.windows.forms.button
me.button2 = new system.windows.forms.button
me.button3 = new system.windows.forms.button
me.button4 = new system.windows.forms.button
me.label1 = new system.windows.forms.label
me.suspendlayout()
'
'listbox1
'
me.listbox1.itemheight = 12
me.listbox1.location = new system.drawing.point(16, 16)
me.listbox1.name = "listbox1"
me.listbox1.size = new system.drawing.size(216, 64)
me.listbox1.tabindex = 1
'
'listbox2
'
me.listbox2.itemheight = 12
me.listbox2.location = new system.drawing.point(16, 88)
me.listbox2.name = "listbox2"
me.listbox2.size = new system.drawing.size(216, 100)
me.listbox2.tabindex = 2
'
'textbox1
'
me.textbox1.location = new system.drawing.point(24, 208)
me.textbox1.name = "textbox1"
me.textbox1.size = new system.drawing.size(208, 21)
me.textbox1.tabindex = 3
me.textbox1.text = "c:/0001.wav"
'
'button1
'
me.button1.location = new system.drawing.point(24, 240)
me.button1.name = "button1"
me.button1.size = new system.drawing.size(64, 24)
me.button1.tabindex = 4
me.button1.text = "recode"
'
'button2
'
me.button2.location = new system.drawing.point(96, 240)
me.button2.name = "button2"
me.button2.size = new system.drawing.size(72, 24)
me.button2.tabindex = 5
me.button2.text = "stop"
'
'button3
'
me.button3.location = new system.drawing.point(176, 240)
me.button3.name = "button3"
me.button3.size = new system.drawing.size(80, 24)
me.button3.tabindex = 6
me.button3.text = "play"
'
'button4
'
me.button4.location = new system.drawing.point(272, 240)
me.button4.name = "button4"
me.button4.size = new system.drawing.size(96, 24)
me.button4.tabindex = 7
me.button4.text = "disposebuff"
'
'label1
'
me.label1.location = new system.drawing.point(248, 16)
me.label1.name = "label1"
me.label1.size = new system.drawing.size(264, 160)
me.label1.tabindex = 8
me.label1.text = "聲音格式"
'
'form1
'
me.autoscalebasesize = new system.drawing.size(6, 14)
me.clientsize = new system.drawing.size(536, 277)
me.controls.add(me.label1)
me.controls.add(me.button4)
me.controls.add(me.button3)
me.controls.add(me.button2)
me.controls.add(me.button1)
me.controls.add(me.textbox1)
me.controls.add(me.listbox2)
me.controls.add(me.listbox1)
me.name = "form1"
me.text = "form1"
me.resumelayout(false)
end sub
#end region
private sub form1_load(byval sender as system.object, byval e as system.eventargs) handles mybase.load
dim info as deviceinformation
'''先得到可以使用的信息
''' 設備信息由這個集合提供
for each info in caplist
listbox1.items.add(info.description)
next
end sub
private sub listbox1_selectedindexchanged(byval sender as system.object, byval e as system.eventargs) handles listbox1.selectedindexchanged
'利用選擇的設備
cap = new capture(caplist(listbox1.selectedindex).driverguid)
'''枚舉支持的格式
'''嘗試各種格式,只能用try catch 了
dim fmt as waveformat
dim testcapture as capturebuffer
dim capturedesc as new capturebufferdescription
'listbox2.items.clear()
scanavailableinputformats(cap)
fillformatlistbox()
end sub
sub scanavailableinputformats(byval cap as capture)
'-----------------------------------------------------------------------------
' name: scanavailableinputformats()
' desc: tests to see if 20 different standard wave formats are supported by
' the capture device
'-----------------------------------------------------------------------------
dim format as new waveformat
dim dscheckboxd as new capturebufferdescription
dim pdscapturebuffer as capturebuffer = nothing
' this might take a second or two, so throw up the hourglass
cursor = cursors.waitcursor
format.formattag = waveformattag.pcm
' try 20 different standard formats to see if they are supported
dim iindex as integer
for iindex = 0 to 19
getwaveformatfromindex(iindex, format)
' to test if a capture format is supported, try to create a
' new capture buffer using a specific format. if it works
' then the format is supported, otherwise not.
dscheckboxd.bufferbytes = format.averagebytespersecond
dscheckboxd.format = format
try
pdscapturebuffer = new capturebuffer(dscheckboxd, cap)
inputformatsupported(iindex) = true
catch
inputformatsupported(iindex) = false
end try
pdscapturebuffer.dispose()
next iindex
cursor = cursors.default
end sub 'scanavailableinputformats
private sub getwaveformatfromindex(byval index as integer, byref format as waveformat)
'-----------------------------------------------------------------------------
' name: getwaveformatfromindex()
' desc: returns 20 different wave formats based on index
'-----------------------------------------------------------------------------
dim samplerate as integer = index / 4
dim itype as integer = index mod 4
select case samplerate
case 0
format.samplespersecond = 48000
case 1
format.samplespersecond = 44100
case 2
format.samplespersecond = 22050
case 3
format.samplespersecond = 11025
case 4
format.samplespersecond = 8000
end select
select case itype
case 0
format.bitspersample = 8
format.channels = 1
case 1
format.bitspersample = 16
format.channels = 1
case 2
format.bitspersample = 8
format.channels = 2
case 3
format.bitspersample = 16
format.channels = 2
end select
format.blockalign = cshort(format.channels * (format.bitspersample / 8))
format.averagebytespersecond = format.blockalign * format.samplespersecond
end sub 'getwaveformatfromindex
private shared function convertwaveformattostring(byval format as waveformat) as string
'-----------------------------------------------------------------------------
' name: convertwaveformattostring()
' desc: converts a wave format to a text string
'-----------------------------------------------------------------------------
return format.samplespersecond.tostring() + " hz, " + format.bitspersample.tostring() + "-bit " + iif(format.channels = 1, "mono", "stereo")
end function 'convertwaveformattostring
sub fillformatlistbox()
'-----------------------------------------------------------------------------
' name: fillformatlistbox()
' desc: fills the format list box based on the availible formats
'-----------------------------------------------------------------------------
dim info as new formatinfo
dim strformatname as string = string.empty
dim format as new waveformat
dim iindex as integer
for iindex = 0 to inputformatsupported.length - 1
if true = inputformatsupported(iindex) then
' turn the index into a waveformat then turn that into a
' string and put the string in the listbox
getwaveformatfromindex(iindex, format)
info.format = format
formats.add(info)
end if
next iindex
listbox2.datasource = formats
end sub 'fillformatlistbox
sub createriff()
'*************************************************************************
'
'
' here is where the file will be created. a
'
' wave file is a riff file, which has chunks
'
' of data that describe what the file contains.
'
' a wave riff file is put together like this:
'
'
'
' the 12 byte riff chunk is constructed like this:
'
' bytes(0 - 3) 'r' 'i' 'f' 'f'
'
' bytes 4 - 7 : length of file, minus the first 8 bytes of the riff description.
'
' (4 bytes for "wave" + 24 bytes for format chunk length +
'
' 8 bytes for data chunk description + actual sample data size.)
'
' bytes(8 - 11) 'w' 'a' 'v' 'e'
'
'
'
' the 24 byte format chunk is constructed like this:
'
' bytes(0 - 3) 'f' 'm' 't' ' '
'
' bytes 4 - 7 : the format chunk length. this is always 16.
'
' bytes 8 - 9 : file padding. always 1.
'
' bytes 10- 11: number of channels. either 1 for mono, or 2 for stereo.
'
' bytes 12- 15: sample rate.
'
' bytes 16- 19: number of bytes per second.
'
' bytes 20- 21: bytes per sample. 1 for 8 bit mono, 2 for 8 bit stereo or
'
' 16 bit mono, 4 for 16 bit stereo.
'
' bytes 22- 23: number of bits per sample.
'
'
'
' the data chunk is constructed like this:
'
' bytes(0 - 3) 'd' 'a' 't' 'a'
'
' bytes 4 - 7 : length of data, in bytes.
'
' bytes 8 -...: actual sample data.
'
'
'
'**************************************************************************
' open up the wave file for writing.
wavefile = new filestream(textbox1.text, filemode.create)
writer = new binarywriter(wavefile)
' set up file with riff chunk info.
dim chunkriff as char() = {"r", "i", "f", "f"}
dim chunktype as char() = {"w", "a", "v", "e"}
dim chunkfmt as char() = {"f", "m", "t", " "}
dim chunkdata as char() = {"d", "a", "t", "a"}
dim shpad as short = 1 ' file padding
dim nformatchunklength as integer = &h10 ' format chunk length.
dim nlength as integer = 0 ' file length, minus first 8 bytes of riff description. this will be filled in later.
dim shbytespersample as short = 0 ' bytes per sample.
' figure out how many bytes there will be per sample.
if 8 = inputformat.bitspersample and 1 = inputformat.channels then
shbytespersample = 1
elseif 8 = inputformat.bitspersample and 2 = inputformat.channels or (16 = inputformat.bitspersample and 1 = inputformat.channels) then
shbytespersample = 2
elseif 16 = inputformat.bitspersample and 2 = inputformat.channels then
shbytespersample = 4
end if
' fill in the riff info for the wave file.
writer.write(chunkriff)
writer.write(nlength)
writer.write(chunktype)
' fill in the format info for the wave file.
writer.write(chunkfmt)
writer.write(nformatchunklength)
writer.write(shpad)
writer.write(inputformat.channels)
writer.write(inputformat.samplespersecond)
writer.write(inputformat.averagebytespersecond)
writer.write(shbytespersample)
writer.write(inputformat.bitspersample)
' now fill in the data chunk.
writer.write(chunkdata)
writer.write(cint(0)) ' the sample length will be written in later.
end sub 'createriff
sub createcapturebuffer()
'-----------------------------------------------------------------------------
' name: createcapturebuffer()
' desc: creates a capture buffer and sets the format
'-----------------------------------------------------------------------------
dim dscheckboxd as new capturebufferdescription
if not nothing is applicationnotify then
applicationnotify.dispose()
applicationnotify = nothing
end if
if not nothing is applicationbuffer then
applicationbuffer.dispose()
applicationbuffer = nothing
end if
if 0 = inputformat.channels then
return
end if
' set the notification size
notifysize = iif(1024 > inputformat.averagebytespersecond / 8, 1024, inputformat.averagebytespersecond / 8)
notifysize -= notifysize mod inputformat.blockalign
' set the buffer sizes
capturebuffersize = notifysize * numberrecordnotifications
' create the capture buffer
dscheckboxd.bufferbytes = capturebuffersize
inputformat.formattag = waveformattag.pcm
dscheckboxd.format = inputformat ' set the format during creatation
applicationbuffer = new capturebuffer(dscheckboxd, cap)
nextcaptureoffset = 0
initnotifications()
end sub 'createcapturebuffer
sub initnotifications()
'-----------------------------------------------------------------------------
' name: initnotifications()
' desc: inits the notifications on the capture buffer which are handled
' in the notify thread.
'-----------------------------------------------------------------------------
if nothing is applicationbuffer then
throw new argumentnullexception
end if
' create a thread to monitor the notify events
if nothing is notifythread then
notifythread = new thread(new threadstart(addressof waitthread))
notifythread.start()
' create a notification event, for when the sound stops playing
notificationevent = new autoresetevent(false)
end if
' setup the notification positions
dim i as integer
for i = 0 to numberrecordnotifications - 1
positionnotify(i).offset = notifysize * i + notifysize - 1
positionnotify(i).eventnotifyhandle = notificationevent.handle
next i
applicationnotify = new notify(applicationbuffer)
' tell directsound when to notify the app. the notification will come in the from
' of signaled events that are handled in the notify thread.
applicationnotify.setnotificationpositions(positionnotify, numberrecordnotifications)
end sub 'initnotifications
private sub waitthread()
while created
'sit here and wait for a message to arrive
notificationevent.waitone(timeout.infinite, true)
recordcaptureddata()
end while
end sub 'waitthread
sub recordcaptureddata()
'-----------------------------------------------------------------------------
' name: recordcaptureddata()
' desc: copies data from the capture buffer to the output buffer
'-----------------------------------------------------------------------------
dim capturedata as byte() = nothing
dim readpos as integer
dim capturepos as integer
dim locksize as integer
if nothing is applicationbuffer or nothing is wavefile then
return
end if
applicationbuffer.getcurrentposition(capturepos, readpos)
locksize = readpos - nextcaptureoffset
if locksize < 0 then
locksize += capturebuffersize
end if
' block align lock size so that we are always write on a boundary
locksize -= locksize mod notifysize
if 0 = locksize then
return
end if
' read the capture buffer.
capturedata = ctype(applicationbuffer.read(nextcaptureoffset, gettype(byte), lockflag.none, locksize), byte())
' write the data into the wav file
writer.write(capturedata, 0, capturedata.length)
' update the number of samples, in bytes, of the file so far.
samplecount += capturedata.length
' move the capture offset along
nextcaptureoffset += capturedata.length
nextcaptureoffset = nextcaptureoffset mod capturebuffersize ' circular buffer
end sub 'recordcaptureddata
private sub listbox2_selectedindexchanged(byval sender as system.object, byval e as system.eventargs) handles listbox2.selectedindexchanged
inputformat = ctype(formats(listbox2.selectedindex), formatinfo).format
label1.text = ctype(listbox2.selecteditem, formatinfo).format.tostring
end sub
sub startorstoprecord(byval startrecording as boolean)
'-----------------------------------------------------------------------------
' name: startorstoprecord()
' desc: starts or stops the capture buffer from recording
'-----------------------------------------------------------------------------
if startrecording then
' create a capture buffer, and tell the capture
' buffer to start recording
createcapturebuffer()
applicationbuffer.start(true)
else
' stop the capture and read any data that
' was not caught by a notification
if nothing is applicationbuffer then
return
end if
' stop the buffer, and read any data that was not
' caught by a notification
applicationbuffer.stop()
recordcaptureddata()
writer.seek(4, seekorigin.begin) ' seek to the length descriptor of the riff file.
writer.write(cint(samplecount + 36)) ' write the file length, minus first 8 bytes of riff description.
writer.seek(40, seekorigin.begin) ' seek to the data length descriptor of the riff file.
writer.write(samplecount) ' write the length of the sample data in bytes.
writer.close() ' close the file now.
writer = nothing ' set the writer to null.
wavefile = nothing ' set the filestream to null.
end if
end sub 'startorstoprecord
private sub button1_click(byval sender as system.object, byval e as system.eventargs) handles button1.click
createriff()
startorstoprecord(true)
end sub
private sub button2_click(byval sender as system.object, byval e as system.eventargs) handles button2.click
startorstoprecord(false)
end sub
private sub button3_click(byval sender as system.object, byval e as system.eventargs) handles button3.click
devplay.setcooperativelevel(me, cooperativelevel.priority)
bufplay = new secondarybuffer(textbox1.text, devplay)
bufplay.play(0, bufferplayflags.default)
end sub
private sub button4_click(byval sender as system.object, byval e as system.eventargs) handles button4.click
bufplay.stop()
bufplay.dispose()
end sub
private sub mainform_closing(byval sender as object, byval e as system.componentmodel.canceleventargs) handles mybase.closing
if not nothing is notificationevent then
notificationevent.set()
end if
if not nothing is applicationbuffer then
if applicationbuffer.capturing then
startorstoprecord(false)
end if
end if
end
end sub 'mainform_closing
end class
=======================================
ok directsound最后的部分寫完了.總體感覺微軟的封裝還是有道理的
既要體現出易用性,而且還要充分發揮硬件的能力.如果你覺得某些特性用不到(很多其實都用不到)
你可以自己在directsound的基礎上制作自己的聲效引擎方便自己使用.
現在也存在不少優秀的聲效引擎(在模擬器里面經常見到),至于是否自己開發,就要看你的興趣了
如果您對directsound感興趣,可以來我的blog或者留言版發表看法.
http://blog.csdn.net/a11s
下一個目標,托管的directplay
(可能跟dsound中間插入ddraw一樣,dplay的時候順便搞定dinput)
==========end directsound 9==================
