nBits = 8 + uint32(bitCount[a>>8])
	}
	e.emitHuff(h, runLength<<4|int32(nBits))
	if nBits > 0 {
		e.emit(uint32(b)&(1<<nBits-1), nBits)
	}
}

// writeMarkerHeader writes the header for a marker with the given length.
func (e *encoder) writeMarkerHeader(marker uint8, markerlen int) {
	e.buf[0] = 0xff
	e.buf[1] = marker
	e.buf[2] = uint8(markerlen >> 8)
	e.buf[3] = uint8(markerlen & 0xff)
	e.write(e.buf[:4])
}