IFFmpegSourceSettings Interface Reference¶

Overview¶

The IFFmpegSourceSettings interface provides advanced configuration options for the FFMPEG Source DirectShow filter. This interface enables developers to control hardware acceleration, buffering behavior, custom FFmpeg options, and various callbacks for media playback.

Interface Definition¶

Interface Name: IFFmpegSourceSettings
GUID: {1974D893-83E4-4F89-9908-795C524CC17E}
Inherits From: IUnknown

Interface Definition Files¶

Complete interface definitions are available on GitHub:

C# (.NET): IFFmpegSourceSettings.cs
C++ Header: IFFmpegSourceSettings.h
Delphi: VCFiltersAPI.pas (search for IFFMPEGSourceSettings)

All interface definitions include:

Complete method signatures with proper marshalling attributes
Callback delegate definitions
Enumeration types (buffering modes, media types)
Usage documentation and examples

Methods Reference¶

Hardware Acceleration¶

GetHWAccelerationEnabled¶

Retrieves the current hardware acceleration state.

Syntax (C++):

BOOL GetHWAccelerationEnabled();

Syntax (C#):

[PreserveSig]
bool GetHWAccelerationEnabled();

Returns: TRUE if hardware acceleration is enabled, FALSE otherwise.

Default: TRUE

SetHWAccelerationEnabled¶

Enables or disables hardware video decoding acceleration. Syntax (C++):

HRESULT SetHWAccelerationEnabled(BOOL enabled);

Syntax (C#):

[PreserveSig]
int SetHWAccelerationEnabled([MarshalAs(UnmanagedType.Bool)] bool enabled);

Parameters: - enabled: Set to TRUE to enable hardware acceleration, FALSE to disable. Returns: S_OK (0) on success, error code otherwise. Usage Notes: - Must be called before connecting downstream video filters - When enabled, the filter attempts to use hardware decoding (DXVA, NVDEC, QuickSync, etc.) - Falls back to software decoding if hardware acceleration is unavailable - Hardware acceleration significantly improves performance for H.264, H.265, VP9, and AV1 codecs Example (C++):

IFFmpegSourceSettings* pSettings = nullptr;
pFilter->QueryInterface(IID_IFFmpegSourceSettings, (void**)&pSettings);
// Enable hardware acceleration
pSettings->SetHWAccelerationEnabled(TRUE);
pSettings->Release();

Example (C#):

var settings = filter as IFFmpegSourceSettings;
if (settings != null)
{
    // Enable hardware acceleration
    settings.SetHWAccelerationEnabled(true);
}

Load Timeout Configuration¶

GetLoadTimeOut¶

Retrieves the current source loading timeout value.

Syntax (C++):

DWORD GetLoadTimeOut();

Syntax (C#):

[PreserveSig]
uint GetLoadTimeOut();

Returns: Timeout value in milliseconds.

Default: 15000 (15 seconds)

SetLoadTimeOut¶

Sets the timeout duration for source loading operations. Syntax (C++):

HRESULT SetLoadTimeOut(DWORD milliseconds);

Syntax (C#):

[PreserveSig]
int SetLoadTimeOut(uint milliseconds);

Parameters: - milliseconds: Timeout duration in milliseconds. Returns: S_OK (0) on success. Usage Notes: - Must be called before loading the source file/URL - Particularly important for network streams that may have slow connection times - Set higher values for slow network connections or large files - Set lower values to fail fast on unreachable sources Example (C++):

// Set 30-second timeout for network streams
pSettings->SetLoadTimeOut(30000);
// Load RTSP stream
IFileSourceFilter* pFileSource = nullptr;
pFilter->QueryInterface(IID_IFileSourceFilter, (void**)&pFileSource);
pFileSource->Load(L"rtsp://example.com/stream", nullptr);

Buffering Configuration¶

GetBufferingMode¶

Retrieves the current buffering mode.

Syntax (C++):

FFMPEG_SOURCE_BUFFERING_MODE GetBufferingMode();

Syntax (C#):

[PreserveSig]
FFMPEG_SOURCE_BUFFERING_MODE GetBufferingMode();

Returns: Current buffering mode (see enumeration below).

Default: FFMPEG_SOURCE_BUFFERING_MODE_AUTO

SetBufferingMode¶

Sets the buffering mode for live sources. Syntax (C++):

HRESULT SetBufferingMode(FFMPEG_SOURCE_BUFFERING_MODE mode);

Syntax (C#):

[PreserveSig]
int SetBufferingMode(FFMPEG_SOURCE_BUFFERING_MODE mode);

Parameters: - mode: Buffering mode to use. Returns: S_OK (0) on success. Usage Notes: - Must be called before loading the source - Affects latency and stability for live streams Buffering Modes: | Mode | Value | Description | Use Case | |------|-------|-------------|----------| | FFMPEG_SOURCE_BUFFERING_MODE_AUTO | 0 | Automatically detect if buffering is needed | Default - recommended for most scenarios | | FFMPEG_SOURCE_BUFFERING_MODE_ON | 1 | Force buffering enabled | Use for unstable network streams | | FFMPEG_SOURCE_BUFFERING_MODE_OFF | 2 | Force buffering disabled | Use for low-latency live streams | Example (C++):

// Disable buffering for low-latency RTSP stream
pSettings->SetBufferingMode(FFMPEG_SOURCE_BUFFERING_MODE_OFF);
pSettings->SetLoadTimeOut(5000); // 5-second timeout

Example (C#):

// Enable buffering for unstable network
settings.SetBufferingMode(FFMPEG_SOURCE_BUFFERING_MODE.ON);

Custom FFmpeg Options¶

SetCustomOption¶

Sets a custom FFmpeg option for the demuxer or decoder.

Syntax (C++):

HRESULT SetCustomOption(LPSTR name, LPSTR value);

Syntax (C#):

[PreserveSig]
int SetCustomOption([MarshalAs(UnmanagedType.LPStr)] string name,
                     [MarshalAs(UnmanagedType.LPStr)] string value);

Parameters:

name: Option name (ASCII string).
value: Option value (ASCII string).

Returns: S_OK (0) on success.

Usage Notes:

Must be called before loading the source
Allows passing any FFmpeg AVFormatContext or AVCodecContext option
Options are passed directly to FFmpeg libraries
Invalid options are ignored with a warning

Common Options:

Option	Value	Description
`rtsp_transport`	`tcp` or `udp`	Force RTSP transport protocol
`timeout`	Microseconds	Network timeout for protocols
`buffer_size`	Bytes	Input buffer size
`analyzeduration`	Microseconds	Duration to analyze stream
`probesize`	Bytes	Size of data to probe
`fflags`	`nobuffer`	Disable buffering
`threads`	Number	Decoder thread count

Example (C++):

// Configure RTSP to use TCP transport
pSettings->SetCustomOption("rtsp_transport", "tcp");

// Set network timeout to 5 seconds
pSettings->SetCustomOption("timeout", "5000000"); // 5 seconds in microseconds

// Increase probe size for better format detection
pSettings->SetCustomOption("probesize", "10000000"); // 10MB

Example (C#):

// Low-latency configuration
settings.SetCustomOption("fflags", "nobuffer");
settings.SetCustomOption("flags", "low_delay");
settings.SetCustomOption("probesize", "32");

ClearCustomOptions¶

Clears all previously set custom options. Syntax (C++):

HRESULT ClearCustomOptions();

Syntax (C#):

[PreserveSig]
int ClearCustomOptions();

Returns: S_OK (0) on success. Usage Notes: - Must be called before loading the source - Resets all custom options to FFmpeg defaults Example (C++):

pSettings->ClearCustomOptions();

Callback Configuration¶

SetDataCallback¶

Sets a callback function to receive decoded video/audio data.

Syntax (C++):

HRESULT SetDataCallback(FFMPEGDataCallbackDelegate callback);

Syntax (C#):

[PreserveSig]
int SetDataCallback([MarshalAs(UnmanagedType.FunctionPtr)] FFMPEGDataCallbackDelegate callback);

Parameters:

callback: Pointer to callback function.

Returns: S_OK (0) on success.

Callback Signature (C++):

typedef HRESULT(_stdcall* FFMPEGDataCallbackDelegate) (
    BYTE* buffer,        // Pointer to data buffer
    int bufferLen,       // Buffer length in bytes
    int dataType,        // 0 = video, 1 = audio
    LONGLONG startTime,  // Start timestamp (100-nanosecond units)
    LONGLONG stopTime    // Stop timestamp (100-nanosecond units)
);

Usage Notes:

Callback is invoked for each decoded frame/audio sample
Called from filter's streaming thread - keep processing minimal
Buffer data is valid only during callback execution
Return S_OK from callback to continue processing

Example (C++):

HRESULT __stdcall DataCallback(BYTE* buffer, int bufferLen, int dataType,
                                LONGLONG startTime, LONGLONG stopTime)
{
    if (dataType == 0) // Video
    {
        // Process video frame
        ProcessVideoFrame(buffer, bufferLen, startTime);
    }
    else // Audio
    {
        // Process audio data
        ProcessAudioData(buffer, bufferLen);
    }
    return S_OK;
}

// Set callback
pSettings->SetDataCallback(&DataCallback);

SetTimestampCallback¶

Sets a callback function to receive timestamp information. Syntax (C++):

HRESULT SetTimestampCallback(FFMPEGTimestampCallbackDelegate callback);

Syntax (C#):

[PreserveSig]
int SetTimestampCallback([MarshalAs(UnmanagedType.FunctionPtr)] FFMPEGTimestampCallbackDelegate callback);

Parameters: - callback: Pointer to callback function. Returns: S_OK (0) on success. Callback Signature (C++):

typedef HRESULT(_stdcall* FFMPEGTimestampCallbackDelegate) (
    int mediaType,              // 0 = video, 1 = audio
    __int64 demuxerStartTime,   // Demuxer start time
    __int64 streamStartTime,    // Stream start time
    __int64 timestamp           // Current timestamp
);

Usage Notes: - Useful for timestamp analysis and synchronization debugging - Called for each decoded frame/sample

Audio Control¶

SetAudioEnabled¶

Enables or disables audio stream processing.

Syntax (C++):

HRESULT SetAudioEnabled(BOOL enabled);

Syntax (C#):

[PreserveSig]
int SetAudioEnabled([MarshalAs(UnmanagedType.Bool)] bool enabled);

Parameters:

enabled: Set to TRUE to enable audio, FALSE to disable.

Returns: S_OK (0) on success.

Usage Notes:

Must be called before loading the source
When disabled, audio streams are not decoded (saves CPU/memory)
Useful for video-only applications

Example (C++):

// Disable audio for video-only processing
pSettings->SetAudioEnabled(FALSE);

IFileSourceFilter - Standard DirectShow interface for loading files/URLs
IAMStreamSelect - Select between multiple audio/video streams
IMediaSeeking - Seek to specific positions in the media
IAMStreamConfig - Configure video/audio format

IFFmpegSourceSettings Interface Reference¶

Overview¶

Interface Definition¶

Interface Definition Files¶

Methods Reference¶

Hardware Acceleration¶

GetHWAccelerationEnabled¶

SetHWAccelerationEnabled¶

Load Timeout Configuration¶

GetLoadTimeOut¶

SetLoadTimeOut¶

Buffering Configuration¶

GetBufferingMode¶

SetBufferingMode¶

Custom FFmpeg Options¶

SetCustomOption¶

ClearCustomOptions¶

Callback Configuration¶

SetDataCallback¶

SetTimestampCallback¶

Audio Control¶

SetAudioEnabled¶

See Also¶

Documentation¶

Interface Definitions¶

Working Samples¶

External Resources¶

IFFmpegSourceSettings Interface Reference¶

Overview¶

Interface Definition¶

Interface Definition Files¶

Methods Reference¶

Hardware Acceleration¶

GetHWAccelerationEnabled¶

SetHWAccelerationEnabled¶

Load Timeout Configuration¶

GetLoadTimeOut¶

SetLoadTimeOut¶

Buffering Configuration¶

GetBufferingMode¶

SetBufferingMode¶

Custom FFmpeg Options¶

SetCustomOption¶

ClearCustomOptions¶

Callback Configuration¶

SetDataCallback¶

SetTimestampCallback¶

Audio Control¶

SetAudioEnabled¶

Related Interfaces¶

See Also¶

Documentation¶

Interface Definitions¶

Working Samples¶

External Resources¶