// Registers a DataFlavor/FE pair
void nsDataObjCollection::AddDataFlavor(const char * aDataFlavor,
LPFORMATETC aFE)
{
// Add the FormatEtc to our list if it's not already there. We don't care
// about the internal aDataFlavor because nsDataObj handles that.
IEnumFORMATETC * ifEtc;
FORMATETC fEtc;
ULONG num;
if (S_OK != this->EnumFormatEtc(DATADIR_GET, &ifEtc))
return;
while (S_OK == ifEtc->Next(1, &fEtc, &num)) {
NS_ASSERTION(1 == num,
"Bit off more than we can chew in nsDataObjCollection::AddDataFlavor");
if (FormatsMatch(fEtc, *aFE)) {
ifEtc->Release();
return;
}
} // If we didn't find a matching format, add this one
ifEtc->Release();
m_enumFE->AddFormatEtc(aFE);
}
AudioConverterStream::AudioConverterStream(WaveFormat sourceFormat, WaveFormat destFormat, WaveFormat** prevSourceFormats , int numPrevSourceFormats)
: outBuffer(nullptr), outSize(0), outBufferAllocated(0), stream(nullptr), isProxy(false), m_failed(false), subConverter(nullptr), startOffset(0)
{
if (sourceFormat.GetSize() == destFormat.GetSize())
{
LPWAVEFORMATEX src = static_cast<LPWAVEFORMATEX>(sourceFormat);
LPWAVEFORMATEX dest = static_cast<LPWAVEFORMATEX>(destFormat);
if (memcmp(src, dest, sourceFormat.GetSize()) == 0)
{
// Source and destination formats are identical, so we'll just pass the input through to
// the output
isProxy = true;
return;
}
}
MMRESULT mm = acmStreamOpen(&stream, nullptr, sourceFormat, destFormat, nullptr, 0, 0, ACM_STREAMOPENF_NONREALTIME);
if (mm != MMSYSERR_NOERROR)
{
// Not supported directly, so try letting ACM suggest an intermediate format, so we can
// perform the conversion in multiple stages.
WaveFormat intermediateFormat;
// This weird looping structure is because we must try all combinations of four flags, and
// even when a given combination yields a valid suggestion, we must be able to backtrack and
// continue looping (tryMoreSuggestions) if the conversion based on that suggestion later
// fails or dead-ends.
bool foundSuggest = false;
int chan, samp, bits, form, done;
for (done = 0; done < 1 && !foundSuggest; foundSuggest ? 0 : ++done)
{
for (chan = 1; chan >= 0 && !foundSuggest; foundSuggest ? 0 : --chan)
{
for (samp = 1; samp >= 0 && !foundSuggest; foundSuggest ? 0 : --samp)
{
for (bits = 0; bits <= 1 && !foundSuggest; foundSuggest ? 0 : ++bits)
{
for (form = 0; form <= 1 && !foundSuggest; foundSuggest ? 0 : ++form)
{
int flags = 0;
flags |= chan ? ACM_FORMATSUGGESTF_NCHANNELS : 0;
flags |= samp ? ACM_FORMATSUGGESTF_NSAMPLESPERSEC : 0;
flags |= bits ? ACM_FORMATSUGGESTF_WBITSPERSAMPLE : 0;
flags |= form ? ACM_FORMATSUGGESTF_WFORMATTAG : 0;
intermediateFormat = destFormat;
MMRESULT mmSuggest = acmFormatSuggest(NULL, sourceFormat, intermediateFormat, intermediateFormat.GetSize(), flags);
if (mmSuggest == MMSYSERR_NOERROR)
{
// Got a possibly-valid suggestion, but it might be a suggestion to
// do absolutely nothing (which would be bad), so we first make sure
// there's some sort of change involved:
if (!FormatsMatch(sourceFormat, intermediateFormat))
{
// We got a suggestion
foundSuggest = true;
// Now check to see if it's identical to a previous conversion
// state. If it is, then we'll revert foundSuggest to false to
// prevent endless conversion cycles.
for (int prev = 0; prev < numPrevSourceFormats && prevSourceFormats && foundSuggest; prev++)
{
WaveFormat& oldFormat = *prevSourceFormats[prev];
if (FormatsMatch(oldFormat, intermediateFormat))
{
// We already went through this exact format
foundSuggest = false;
}
}
}
}
tryMoreSuggestions:
continue;
}
}
}
}
}
if (!foundSuggest)
{
m_failed = true;
return;
}
// we'll handle conversion to the intermediate format
mm = acmStreamOpen(&stream, nullptr, sourceFormat, intermediateFormat, nullptr, 0, 0, ACM_STREAMOPENF_NONREALTIME);
if (mm != MMSYSERR_NOERROR)
{
if (!done)
{
foundSuggest = false;
goto tryMoreSuggestions; // continue the search
}
// reached dead end
m_failed = true;
return;
}
// create temporary updated conversion history for cycle prevention
size_t prevSize = sizeof(WaveFormat*) * (numPrevSourceFormats + 1);
WaveFormat** prevFormats = static_cast<WaveFormat**>(alloca(prevSize));
if (prevSourceFormats)
{
memcpy(prevFormats, prevSourceFormats, prevSize);
}
prevFormats[numPrevSourceFormats] = &sourceFormat;
// delegate the rest of the conversion to a new converter (recursive construction)
subConverter = new AudioConverterStream(intermediateFormat, destFormat, prevFormats, numPrevSourceFormats + 1);
if (subConverter->m_failed)
{
delete subConverter;
subConverter = nullptr;
if (!done)
{
foundSuggest = false;
goto tryMoreSuggestions; // continue the search
}
// reached dead end
m_failed = true;
return;
}
}
// prepare the stream header
memset(&header, 0, sizeof(ACMSTREAMHEADER));
header.cbStruct = sizeof(ACMSTREAMHEADER);
header.pbSrc = inWorkBuffer;
header.cbSrcLength = sizeof(inWorkBuffer);
header.pbDst = outWorkBuffer;
header.cbDstLength = sizeof(outWorkBuffer);
mm = acmStreamPrepareHeader(stream, &header, 0);
if (mm != MMSYSERR_NOERROR)
{
m_failed = true;
}
}
