External source properties

The video capture API includes constants for managing the retrieval and deinterlacing of frames brought in from an external source.

The following constants are used to set properties when getting and deinterlacing frames from videos brought in from an external source such as a USB memory stick:

CAPTURE_FLAG_EXTERNAL_SOURCE
0x0002
Bit to set if the context to create is for an external source.

The following properties are used for deinterlacing frames brought in from an external source. They are relevant only when the CAPTURE_FLAG_EXTERNAL_SOURCE flag is set.

CAPTURE_FLAG_FREE_BUFFER
0x0002
Request a free buffer in which to put a frame from an external source.
CAPTURE_BUFFER_USAGE_RDONLY
0x001
Mark the buffer as read-only.
CAPTURE_PROPERTY_BUFFER_USAGE
CAPTURE_PROPERTY( 'Q', 'B', 'U', 'S' )
Read/Write [] uint32_t
An array of buffer usage flags. Element i indicates if the capture driver has only read (CAPTURE_BUFFER_USAGE_RDONLY) or read/write (CAPTURE_BUFFER_USAGE_RDWR) permission for buffer >i. The default is read-write permission.
CAPTURE_PROPERTY_BUFFER_INDEX
CAPTURE_PROPERTY( 'Q', 'B', 'I', 'X' )
Write uint32_t
The index of the buffer to be injected by capture_put_buffer().
CAPTURE_PROPERTY_BUFFER_NFIELDS
CAPTURE_PROPERTY( 'Q', 'B', 'N', 'F' )
Write uint32_t
The number of fields contained in the buffer injected by capture_put_buffer().
CAPTURE_PROPERTY_BUFFER_PLANAR_OFFSETS
CAPTURE_PROPERTY( 'Q', 'B', 'P', 'O' )
Write [][3] int32_t
A per-buffer array. The array has one row per field. Each row indicates the offset from the base address for each of the Y, U, and V components of planar YUV formats.
CAPTURE_PROPERTY_BUFFER_FLAGS
CAPTURE_PROPERTY( 'Q', 'B', 'F', 'L' )
Write [] uint32_t
A per-buffer array of buffer flag. The flag is a bit-field.
CAPTURE_PROPERTY_BUFFER_SEQNO
CAPTURE_PROPERTY( 'Q', 'B', 'S', 'N' )
Write [] uint32_t
A per-buffer array of sequence numbers. Each element indicates the sequence number of the field contained in the buffer.