wmfunctions.cpp File Reference

Implements that which uses the Windows Media SDK codec, profile, and information functions such as enumeration of codecs and their formats and matching mixer audio formats to codec inputs. More...

#include "stdafx.h"
#include "wmfunctions.h"
#include "exports.h"
#include <wmsdk.h>
#include <map>
#include "AudRecordInt.h"
#include "misc.h"

Classes
struct	CodecConfigTemp
struct	InputFormat
Typedefs
typedef std::vector < CodecConfigTemp >	CodecConfigList
typedef CodecConfigList::iterator	CodecConfigIter
typedef CodecConfigList::const_iterator	CodecConfigConstIter
typedef std::map< std::wstring, CodecConfigList >	CodecInformation
typedef CodecInformation::iterator	CodecInfoIter
typedef CodecInformation::const_iterator	CodecInfoConstIter
typedef std::vector< InputFormat >	FormatVector
Functions
HRESULT	GetCodecAndProfileDescriptions (CodecConfigs *&pConfigs)
void	FreeCodecAndProfileDescriptions (CodecConfigs *pCodecConfigs)
HRESULT	MatchCodecInputFormat (IWMWriter *pWriter, const WAVEFORMATEX &sourceFormat, WAVEFORMATEX &codecFormat)
HRESULT	CreateAudRecordObject (CodecConfiguration *pCodecConfig, IAudRecord **ppAudRecord)

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Detailed Description

Implements that which uses the Windows Media SDK codec, profile, and information functions such as enumeration of codecs and their formats and matching mixer audio formats to codec inputs.

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Function Documentation

HRESULT CreateAudRecordObject	(	CodecConfiguration *	pCodecConfig,
		IAudRecord **	ppAudRecord
	)

Creates a IWMWriter interface then creates an AudRecord object

Parameters:

	pCodecConfig	Initial codec configuration for the recording stream
[out]	ppAudRecord	Pointer that receives the new interface pointer

Returns:

The value returned by AudRecord::Create()

void FreeCodecAndProfileDescriptions

(

CodecConfigs *

pCodecConfigs

)

Frees the memory and references associasted with the codecs and their configurations

Returns:

pCodecConfigs Codec configurations to release

HRESULT GetCodecAndProfileDescriptions

(

CodecConfigs *&

pConfigs

)

Enumerates all codecs available for use on the system and their CBR and VBR configurations.

Loops through all the codecs getting their name and configurations and stores them in a map. The map is then serialised into one big memory block by SerializeCodecConfigs(). The references

Parameters:

[out]

pConfigs

On success, a pointer that is set to a struct containing information about the codecs and their info

Returns:

S_OK on success, COM or NS_E_* error code on failure

HRESULT MatchCodecInputFormat	(	IWMWriter *	pWriter,
		const WAVEFORMATEX &	sourceFormat,
		WAVEFORMATEX &	codecFormat
	)

Finds the closest codec input wave format for a source wave format

Enumerates all input formats available on the writer, then tries to match the number of channels, sample rate, and bits per sample of the input format. If there isn't an exact match, the algorithm to find a match uses the following steps: Bits per sample is continually degraded by 8 bits until there's a match Sample format is set to integer PCM then step 1 is retried again Number of channels is reduced to 2, then step 2 is retried again Gives up

Parameters:

pWriter	The Windows Media writer whose codec input formats are to be used
sourceFormat	Source format to try and match
codecFormat	Closest match returned by the function

Returns:

S_OK if a match was found, NS_E_INVALID_INPUT_FORMAT if a match couldn't be found or a standard COM or NS_E_* error on other failure