Buffer.mapRange

bool mapRange(uint idx, int length, out gst.map_info.MapInfo info, gst.types.MapFlags flags)

Fills info with the #GstMapInfo of length merged memory blocks starting at idx in buffer. When length is -1, all memory blocks starting from idx are merged and mapped.

flags describe the desired access of the memory. When flags is #GST_MAP_WRITE, buffer should be writable (as returned from gst_buffer_is_writable()).

When buffer is writable but the memory isn't, a writable copy will automatically be created and returned. The readonly copy of the buffer memory will then also be replaced with this writable copy.

The memory in info should be unmapped with [gst.buffer.Buffer.unmap] after usage.

Parameters

`idx`	an index
`length`	a length
`info`	info about the mapping
`flags`	flags for the mapping

Returns

true if the map succeeded and info contains valid

data.