AVCapture

Supported Hardware Devices: Pro Capture cards

Contents Demonstrated in the Sample:

1. Preview captured video and monitor captured audio
2. Freely select video capture devices and their corresponding audio devices
3. Freely switch capture parameters: resolution, frame rate, color space
4. Support multi-channel capture: simultaneously capture one or two audio/video streams and render them separately.
5. Record captured audio and video data as FLV files.

Call Logic:

1. Obtain version information, initialize and enumerate devices: MWGetVersion, MWCaptureInitInstance, MWRefreshDevice, MWGetChannelCount
2. Filter supported devices based on device information and interface information: MWGetChannelInfoByIndex
3. Create a video rendering layer and overlay it on the current window: createPreviewLayer
4. Open channel: MWGetDevicePath, MWOpenChannelByPath
5. Create audio renderer: MWAudioRenderCreate, MWAudioRenderStart
6. Start video capture and rendering thread
7. Start audio capture and rendering thread
8. Enter main thread loop
9. Click menu to switch audio/video channels or capture parameters:
   1. Stop audio capture and rendering thread
   2. Stop video capture and rendering thread
   3. Destroy audio renderer: MWAudioRenderStop, MWAudioRenderDestroy
   4. Close channel: MWCloseChannel
   5. Open channel and capture/render according to set channel and capture parameters: steps 4, 5, 6, 7
10. After clicking the close button, exit capture and release resources:
    1. Stop audio capture and rendering thread
    2. Stop video capture and rendering thread
    3. Destroy audio renderer: MWAudioRenderStop, MWAudioRenderDestroy
    4. Close channel: MWCloseChannel
    5. Destroy instance: MWCaptureExitInstance.

Video Capture and Rendering Thread:

1. Start video capture: MMWStartVideoCapture
2. Create Event: MWCreateEvent
3. Register timer: MWRegisterTimer
4. Set time schedule: MWScheduleTimer
5. Wait for Event: MWTryWaitEvent, MWWaitEvent, MWMultiWaitEvent
6. Capture video data: MWCaptureVideoFrameToVirtualAddressEx
7. Get current capture status and release capture card resources: MWGetVideoCaptureStatus
8. Repeat steps 4, 5, 6, 7 until thread exits
9. Unregister timer: MWUnregisterTimer
10. Close Event: MWCloseEvent
11. Stop capture: MWStopVideoCapture

Audio Capture and Rendering Thread:

1. Start audio capture: MWStartAudioCapture
2. Create Event: MWCreateEvent
3. Register message notification: MWRegisterNotify
4. Wait for Event: MWTryWaitEvent, MWWaitEvent, MWMultiWaitEvent
5. Capture audio data: MWCaptureAudioFrame
6. Render audio data
7. Repeat steps 4, 5, 6 until thread exits
8. Unregister message notification: MWUnregisterNotify
9. Close Event: MWCloseEvent
10. Stop capture: MWStopAudioCapture

Result:

Flowchart: