DSPACKコンポーネントライブラリを使用してDelphi6で記述されたDirectShowアプリケーションがあります。フィルタで入力行を有効にするという奇妙な問題が発生しています。入力行（この場合は「マイク」という名前）が見つかるまでピンを検索し、フィルターグラフがアクティブなときにput_Enable（true）を呼び出します。これを行うと、HRESULTとして$80004005の「不特定のエラー」が発生します。
入力ラインを有効にする前に、フィルターの出力オーディオメディアタイプを設定していますが、何かが正しく機能していません。アプリケーションを作成するために使用した元のDirectShowサンプルは正常に機能します。フィルタグラフを作成するのとまったく同じ手順を実行していると思います。もちろん、何かを見逃した可能性があります。この問題を解決するために私が試みることができることについて誰かが何かヒントやアイデアを持っていますか？以下のコードスニペットは、私が行っていることを部分的に示していますが、非常に長いため、それに至るまでのすべてのステップではありません。私がテストに使用しているキャプチャデバイスは、「マイク」という名前の単一の入力ラインを備えたVOIPヘッドセットです。
// The function I call to find an enable the first input line I find in the filter.
function findAndEnableFirstInputLineFound(intfBaseFilter: IBaseFilter; out strInputLineUsed: string): boolean;
var
thePinList: TPinList;
i: integer;
ABool: LongBool;
begin
strInputLineUsed := '';
if not Assigned(intfBaseFilter) then
raise Exception.Create('(findAndEnableFirstInputLineFound) The base filter interface object is unassigned.');
// Now enable the first input source we can find.
Result := false;
thePinList := TPinList.Create(intfBaseFilter);
try
if thePinList.Count > 0 then
begin
// Scan the pin list looking for an input pin.
i := 0;
while (i < thePinList.Count) and (not Result) do
begin
if thePinList.PinInfo[i].dir = PINDIR_INPUT then
begin
// Found one. Enable it.
with thePinList.Items[i] as IAMAudioInputMixer do
begin
CheckDSEror(put_Enable(true)); // $80004005 error occurs here.
// Return the name of the input line used.
strInputLineUsed := thePinList.PinInfo[i].achName;
end; // with thePinList.Items[i] as IAMAudioInputMixer do
Result := true;
break; // Stop looping.
end; // if thePinList.PinInfo[i].dir = PINDIR_INPUT then
Inc(i);
end; // while()
end; // if thePinList.Count > 0 then
finally
thePinList.Free;
end; // try
end;
// The initialization procedure that calls the function above. It is run after the
// the Filter Graph is activated but before it is played.
procedure TDXChain_wavaudio.initializeCaptureFilter;
var
theMediaType: TMediaType;
intfCapturePin: IPin;
aryEnabledInputLines: TDynamicStringArray;
begin
theMediaType := nil;
intfCapturePin := nil;
aryEnabledInputLines := nil;
if not FFilterGraph.Active then
raise Exception.Create('(TDXChain_wavaudio.Create::initializeCaptureFilter) The Filter Graph is INACTIVE.');
if Assigned(FCaptureFilter) then
begin
// Make sure the Capture Filter's output pins supports the
// configured WAV format.
with FOwner.ati_WaveFormatEx do
begin
// if not Assigned(findAudioMediaTypeByFormat(FCaptureFilter_mediatypes, nSamplesPerSec, wBitsPerSample, nChannels)) then
theMediaType := findAudioMediaTypeExt_outputs(FCaptureFilter as IBaseFilter, nSamplesPerSec, wBitsPerSample, nChannels);
if not Assigned(theMediaType) then
// The capture device does not directly support the desired
// WAV format. This is not allowed currently.
raise Exception.Create('(TDXChain_wavaudio.Create::initializeCaptureFilter) The audio input device''s output pins does not support the given WAV format: '
+ CRLF
+ Format('(Device name: %s, Sample Rate: %d, Bits Per Sample: %d, Number of Channels: %d)',
[FOwner.FCaptureFilterConfigInfo.filterName, nSamplesPerSec, wBitsPerSample, nChannels])
);
// -------------- SET OUTPUT PINS TO MEDIA TYPE -------------
// Set the output pins to the desired format.
setPinAudMediaType_outputs(FCaptureFilter, theMediaType.AMMediaType);
// Don't need the media type anymore.
FreeAndNil(theMediaType);
end; // with FOwner.ati_WaveFormatEx do
// Enable at least one input line.
if FOwner.FCaptureFilterConfigInfo.inputPinName = '' then
begin
// No input name was specified so use the first one found.
if not findAndEnableFirstInputLineFound(FCaptureFilter as IBaseFilter, FOwner.FInputLineUsed) then
raise Exception.Create(
'(TDXChain_wavaudio.Create::initializeCaptureFilter) Unable to find a suitable input line for the audio input device named: '
+ FOwner.FCaptureFilterConfigInfo.filterName);
end
else
begin
// Now find the desired available input line and enable it.
if not findAndEnableInputLineByName(FOwner.FCaptureFilterConfigInfo.inputPinName, FCaptureFilter as IBaseFilter, FOwner.FInputLineUsed) then
raise Exception.Create(
'(TDXChain_wavaudio.Create::initializeCaptureFilter) Unable to find the input line named ('
+ FOwner.FCaptureFilterConfigInfo.inputPinName
+ ') for the audio input device named: '
+ FOwner.FCaptureFilterConfigInfo.filterName);
end; // else - if FOwner.FCaptureFilterConfigInfo.inputPinName = '' then
aryEnabledInputLines := getEnabledInputLineNames(FCaptureFilter as IBaseFilter);
if Length(aryEnabledInputLines) < 1 then
raise Exception.Create('(TDXChain_wavaudio.Create::initializeCaptureFilter) No input lines are enabled..');
// ------------------ BUFFER LATENCY --------------------
// Get a reference to the output pin for audio the capture device.
with FCaptureFilter as IBaseFilter do
CheckDSError(findPin(StringToOleStr('Capture'), intfCapturePin));
if not Assigned(intfCapturePin) then
raise Exception.Create('(TDXChain_wavaudio.Create::initializeCaptureFilter) Unable to find the audio input device''s Capture output pin.');
// Set the capture device buffer to 50 ms worth of audio data to
// reduce latency. NOTE: This will fail if the device does not
// support the latency you desire so make sure you watch out for that.
setBufferLatency(intfCapturePin as IAMBufferNegotiation, FOwner.ati_BufferLatency_ms, FOwner.FMediaType);
end; // if Assigned(FCaptureFilter) then
end;