How to Play a File Clip

[MFPlay is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. ]

This topic describes how to play a segment of a media file in MFPlay, by setting the start and stop times for playback.

Ee663591.wedge(en-us,VS.85).gifTo Play a File Clip

  1. Call IMFPMediaPlayer::CreateMediaItemFromURL or IMFPMediaPlayer::CreateMediaItemFromObject to create a media item for the file.
  2. Optionally, get the total duration of the file, as described in How to Get the Playback Duration.
  3. Call IMFPMediaItem::SetStartStopPosition to set the start and stop times. The stop time must not exceed the file duration.
  4. Call IMFPMediaPlayer::SetMediaItem to start playback.

The following example uses the blocking version of CreateMediaItemFromURL. If the non-blocking version is used, the code that appears after CreateMediaItemFromURL should be placed in the handler for the MFP_EVENT_TYPE_MEDIAITEM_CREATED event. For more information about events in MFPlay, see Receiving Events From the Player.

To get the file duration, this example calls the GetPlaybackDuration function shown in the topic How to Get the Playback Duration.


HRESULT PlayMediaClip(
    IMFPMediaPlayer *pPlayer,
    PCWSTR pszURL,
    LONGLONG    hnsStart,
    LONGLONG    hnsEnd
    )
{
    IMFPMediaItem *pItem = NULL;
    PROPVARIANT varStart, varEnd;

    ULONGLONG hnsDuration = 0;

    HRESULT hr = pPlayer->CreateMediaItemFromURL(pszURL, TRUE, 0, &pItem);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = GetPlaybackDuration(pItem, &hnsDuration);
    if (FAILED(hr))
    {
        goto done;
    }

    if ((ULONGLONG)hnsEnd > hnsDuration)
    {
        hnsEnd = hnsDuration;
    }

    hr = InitPropVariantFromInt64(hnsStart, &varStart);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = InitPropVariantFromInt64(hnsEnd, &varEnd);
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pItem->SetStartStopPosition(
        &MFP_POSITIONTYPE_100NS,
        &varStart,
        &MFP_POSITIONTYPE_100NS,
        &varEnd
        );
    if (FAILED(hr))
    {
        goto done;
    }

    hr = pPlayer->SetMediaItem(pItem);

done:
    SafeRelease(&pItem);
    return hr;
}


Requirements

MFPlay requires Windows 7.

Related topics

Using MFPlay for Audio/Video Playback

 

 

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